GCFGlobal Logo

  • Get started with computers
  • Learn Microsoft Office
  • Apply for a job
  • Improve my work skills
  • Design nice-looking docs
  • Getting Started
  • Smartphones & Tablets
  • Typing Tutorial
  • Online Learning
  • Basic Internet Skills
  • Online Safety
  • Social Media
  • Zoom Basics
  • Google Docs
  • Google Sheets
  • Career Planning
  • Resume Writing
  • Cover Letters
  • Job Search and Networking
  • Business Communication
  • Entrepreneurship 101
  • Careers without College
  • Job Hunt for Today
  • 3D Printing
  • Freelancing 101
  • Personal Finance
  • Sharing Economy
  • Decision-Making
  • Graphic Design
  • Photography
  • Image Editing
  • Learning WordPress
  • Language Learning
  • Critical Thinking
  • For Educators
  • Translations
  • Staff Picks
  • English expand_more expand_less

Critical Thinking and Decision-Making  - Logical Fallacies

Critical thinking and decision-making  -, logical fallacies, critical thinking and decision-making logical fallacies.

GCFLearnFree Logo

Critical Thinking and Decision-Making: Logical Fallacies

Lesson 7: logical fallacies.

/en/problem-solving-and-decision-making/how-critical-thinking-can-change-the-game/content/

Logical fallacies

If you think about it, vegetables are bad for you. I mean, after all, the dinosaurs ate plants, and look at what happened to them...

illustration of a dinosaur eating leaves while a meteor falls in the background

Let's pause for a moment: That argument was pretty ridiculous. And that's because it contained a logical fallacy .

A logical fallacy is any kind of error in reasoning that renders an argument invalid . They can involve distorting or manipulating facts, drawing false conclusions, or distracting you from the issue at hand. In theory, it seems like they'd be pretty easy to spot, but this isn't always the case.

Watch the video below to learn more about logical fallacies.

Sometimes logical fallacies are intentionally used to try and win a debate. In these cases, they're often presented by the speaker with a certain level of confidence . And in doing so, they're more persuasive : If they sound like they know what they're talking about, we're more likely to believe them, even if their stance doesn't make complete logical sense.

illustration of a politician saying, "I know for a fact..."

False cause

One common logical fallacy is the false cause . This is when someone incorrectly identifies the cause of something. In my argument above, I stated that dinosaurs became extinct because they ate vegetables. While these two things did happen, a diet of vegetables was not the cause of their extinction.

illustration showing that extinction was not caused by some dinosaurs being vegetarians

Maybe you've heard false cause more commonly represented by the phrase "correlation does not equal causation ", meaning that just because two things occurred around the same time, it doesn't necessarily mean that one caused the other.

A straw man is when someone takes an argument and misrepresents it so that it's easier to attack . For example, let's say Callie is advocating that sporks should be the new standard for silverware because they're more efficient. Madeline responds that she's shocked Callie would want to outlaw spoons and forks, and put millions out of work at the fork and spoon factories.

illustration of Maddie accusing Callie of wanting to outlaw spoons and forks

A straw man is frequently used in politics in an effort to discredit another politician's views on a particular issue.

Begging the question

Begging the question is a type of circular argument where someone includes the conclusion as a part of their reasoning. For example, George says, “Ghosts exist because I saw a ghost in my closet!"

illustration of George claiming that ghosts exists and him seeing one in his closet

George concluded that “ghosts exist”. His premise also assumed that ghosts exist. Rather than assuming that ghosts exist from the outset, George should have used evidence and reasoning to try and prove that they exist.

illustration of George using math and reasoning to try and prove that ghosts exist

Since George assumed that ghosts exist, he was less likely to see other explanations for what he saw. Maybe the ghost was nothing more than a mop!

illustration of a splitscreen showing a ghost in a closet on the left, and that same closet with a mop in it on the right

False dilemma

The false dilemma (or false dichotomy) is a logical fallacy where a situation is presented as being an either/or option when, in reality, there are more possible options available than just the chosen two. Here's an example: Rebecca rings the doorbell but Ethan doesn't answer. She then thinks, "Oh, Ethan must not be home."

illustration showing the false dilemma of either Ethan being home or his home being empty

Rebecca posits that either Ethan answers the door or he isn't home. In reality, he could be sleeping, doing some work in the backyard, or taking a shower.

illustration of Ethan sleeping, doing yard work, and taking a shower

Most logical fallacies can be spotted by thinking critically . Make sure to ask questions: Is logic at work here or is it simply rhetoric? Does their "proof" actually lead to the conclusion they're proposing? By applying critical thinking, you'll be able to detect logical fallacies in the world around you and prevent yourself from using them as well.

previous

Library Home

Introduction to Logic and Critical Thinking

(10 reviews)

critical thinking and logical fallacies

Matthew Van Cleave, Lansing Community College

Copyright Year: 2016

Publisher: Matthew J. Van Cleave

Language: English

Formats Available

Conditions of use.

Attribution

Learn more about reviews.

Reviewed by "yusef" Alexander Hayes, Professor, North Shore Community College on 6/9/21

Formal and informal reasoning, argument structure, and fallacies are covered comprehensively, meeting the author's goal of both depth and succinctness. read more

Comprehensiveness rating: 5 see less

Formal and informal reasoning, argument structure, and fallacies are covered comprehensively, meeting the author's goal of both depth and succinctness.

Content Accuracy rating: 5

The book is accurate.

Relevance/Longevity rating: 5

While many modern examples are used, and they are helpful, they are not necessarily needed. The usefulness of logical principles and skills have proved themselves, and this text presents them clearly with many examples.

Clarity rating: 5

It is obvious that the author cares about their subject, audience, and students. The text is comprehensible and interesting.

Consistency rating: 5

The format is easy to understand and is consistent in framing.

Modularity rating: 5

This text would be easy to adapt.

Organization/Structure/Flow rating: 5

The organization is excellent, my one suggestion would be a concluding chapter.

Interface rating: 5

I accessed the PDF version and it would be easy to work with.

Grammatical Errors rating: 5

The writing is excellent.

Cultural Relevance rating: 5

This is not an offensive text.

Reviewed by Susan Rottmann, Part-time Lecturer, University of Southern Maine on 3/2/21

I reviewed this book for a course titled "Creative and Critical Inquiry into Modern Life." It won't meet all my needs for that course, but I haven't yet found a book that would. I wanted to review this one because it states in the preface that it... read more

Comprehensiveness rating: 4 see less

I reviewed this book for a course titled "Creative and Critical Inquiry into Modern Life." It won't meet all my needs for that course, but I haven't yet found a book that would. I wanted to review this one because it states in the preface that it fits better for a general critical thinking course than for a true logic course. I'm not sure that I'd agree. I have been using Browne and Keeley's "Asking the Right Questions: A Guide to Critical Thinking," and I think that book is a better introduction to critical thinking for non-philosophy majors. However, the latter is not open source so I will figure out how to get by without it in the future. Overall, the book seems comprehensive if the subject is logic. The index is on the short-side, but fine. However, one issue for me is that there are no page numbers on the table of contents, which is pretty annoying if you want to locate particular sections.

Content Accuracy rating: 4

I didn't find any errors. In general the book uses great examples. However, they are very much based in the American context, not for an international student audience. Some effort to broaden the chosen examples would make the book more widely applicable.

Relevance/Longevity rating: 4

I think the book will remain relevant because of the nature of the material that it addresses, however there will be a need to modify the examples in future editions and as the social and political context changes.

Clarity rating: 3

The text is lucid, but I think it would be difficult for introductory-level students who are not philosophy majors. For example, in Browne and Keeley's "Asking the Right Questions: A Guide to Critical Thinking," the sub-headings are very accessible, such as "Experts cannot rescue us, despite what they say" or "wishful thinking: perhaps the biggest single speed bump on the road to critical thinking." By contrast, Van Cleave's "Introduction to Logic and Critical Thinking" has more subheadings like this: "Using your own paraphrases of premises and conclusions to reconstruct arguments in standard form" or "Propositional logic and the four basic truth functional connectives." If students are prepared very well for the subject, it would work fine, but for students who are newly being introduced to critical thinking, it is rather technical.

It seems to be very consistent in terms of its terminology and framework.

Modularity rating: 4

The book is divided into 4 chapters, each having many sub-chapters. In that sense, it is readily divisible and modular. However, as noted above, there are no page numbers on the table of contents, which would make assigning certain parts rather frustrating. Also, I'm not sure why the book is only four chapter and has so many subheadings (for instance 17 in Chapter 2) and a length of 242 pages. Wouldn't it make more sense to break up the book into shorter chapters? I think this would make it easier to read and to assign in specific blocks to students.

Organization/Structure/Flow rating: 4

The organization of the book is fine overall, although I think adding page numbers to the table of contents and breaking it up into more separate chapters would help it to be more easily navigable.

Interface rating: 4

The book is very simply presented. In my opinion it is actually too simple. There are few boxes or diagrams that highlight and explain important points.

The text seems fine grammatically. I didn't notice any errors.

The book is written with an American audience in mind, but I did not notice culturally insensitive or offensive parts.

Overall, this book is not for my course, but I think it could work well in a philosophy course.

critical thinking and logical fallacies

Reviewed by Daniel Lee, Assistant Professor of Economics and Leadership, Sweet Briar College on 11/11/19

This textbook is not particularly comprehensive (4 chapters long), but I view that as a benefit. In fact, I recommend it for use outside of traditional logic classes, but rather interdisciplinary classes that evaluate argument read more

Comprehensiveness rating: 3 see less

This textbook is not particularly comprehensive (4 chapters long), but I view that as a benefit. In fact, I recommend it for use outside of traditional logic classes, but rather interdisciplinary classes that evaluate argument

To the best of my ability, I regard this content as accurate, error-free, and unbiased

The book is broadly relevant and up-to-date, with a few stray temporal references (sydney olympics, particular presidencies). I don't view these time-dated examples as problematic as the logical underpinnings are still there and easily assessed

Clarity rating: 4

My only pushback on clarity is I didn't find the distinction between argument and explanation particularly helpful/useful/easy to follow. However, this experience may have been unique to my class.

To the best of my ability, I regard this content as internally consistent

I found this text quite modular, and was easily able to integrate other texts into my lessons and disregard certain chapters or sub-sections

The book had a logical and consistent structure, but to the extent that there are only 4 chapters, there isn't much scope for alternative approaches here

No problems with the book's interface

The text is grammatically sound

Cultural Relevance rating: 4

Perhaps the text could have been more universal in its approach. While I didn't find the book insensitive per-se, logic can be tricky here because the point is to evaluate meaningful (non-trivial) arguments, but any argument with that sense of gravity can also be traumatic to students (abortion, death penalty, etc)

No additional comments

Reviewed by Lisa N. Thomas-Smith, Graduate Part-time Instructor, CU Boulder on 7/1/19

The text covers all the relevant technical aspects of introductory logic and critical thinking, and covers them well. A separate glossary would be quite helpful to students. However, the terms are clearly and thoroughly explained within the text,... read more

The text covers all the relevant technical aspects of introductory logic and critical thinking, and covers them well. A separate glossary would be quite helpful to students. However, the terms are clearly and thoroughly explained within the text, and the index is very thorough.

The content is excellent. The text is thorough and accurate with no errors that I could discern. The terminology and exercises cover the material nicely and without bias.

The text should easily stand the test of time. The exercises are excellent and would be very helpful for students to internalize correct critical thinking practices. Because of the logical arrangement of the text and the many sub-sections, additional material should be very easy to add.

The text is extremely clearly and simply written. I anticipate that a diligent student could learn all of the material in the text with little additional instruction. The examples are relevant and easy to follow.

The text did not confuse terms or use inconsistent terminology, which is very important in a logic text. The discipline often uses multiple terms for the same concept, but this text avoids that trap nicely.

The text is fairly easily divisible. Since there are only four chapters, those chapters include large blocks of information. However, the chapters themselves are very well delineated and could be easily broken up so that parts could be left out or covered in a different order from the text.

The flow of the text is excellent. All of the information is handled solidly in an order that allows the student to build on the information previously covered.

The PDF Table of Contents does not include links or page numbers which would be very helpful for navigation. Other than that, the text was very easy to navigate. All the images, charts, and graphs were very clear

I found no grammatical errors in the text.

Cultural Relevance rating: 3

The text including examples and exercises did not seem to be offensive or insensitive in any specific way. However, the examples included references to black and white people, but few others. Also, the text is very American specific with many examples from and for an American audience. More diversity, especially in the examples, would be appropriate and appreciated.

Reviewed by Leslie Aarons, Associate Professor of Philosophy, CUNY LaGuardia Community College on 5/16/19

This is an excellent introductory (first-year) Logic and Critical Thinking textbook. The book covers the important elementary information, clearly discussing such things as the purpose and basic structure of an argument; the difference between an... read more

This is an excellent introductory (first-year) Logic and Critical Thinking textbook. The book covers the important elementary information, clearly discussing such things as the purpose and basic structure of an argument; the difference between an argument and an explanation; validity; soundness; and the distinctions between an inductive and a deductive argument in accessible terms in the first chapter. It also does a good job introducing and discussing informal fallacies (Chapter 4). The incorporation of opportunities to evaluate real-world arguments is also very effective. Chapter 2 also covers a number of formal methods of evaluating arguments, such as Venn Diagrams and Propositional logic and the four basic truth functional connectives, but to my mind, it is much more thorough in its treatment of Informal Logic and Critical Thinking skills, than it is of formal logic. I also appreciated that Van Cleave’s book includes exercises with answers and an index, but there is no glossary; which I personally do not find detracts from the book's comprehensiveness.

Overall, Van Cleave's book is error-free and unbiased. The language used is accessible and engaging. There were no glaring inaccuracies that I was able to detect.

Van Cleave's Textbook uses relevant, contemporary content that will stand the test of time, at least for the next few years. Although some examples use certain subjects like former President Obama, it does so in a useful manner that inspires the use of critical thinking skills. There are an abundance of examples that inspire students to look at issues from many different political viewpoints, challenging students to practice evaluating arguments, and identifying fallacies. Many of these exercises encourage students to critique issues, and recognize their own inherent reader-biases and challenge their own beliefs--hallmarks of critical thinking.

As mentioned previously, the author has an accessible style that makes the content relatively easy to read and engaging. He also does a suitable job explaining jargon/technical language that is introduced in the textbook.

Van Cleave uses terminology consistently and the chapters flow well. The textbook orients the reader by offering effective introductions to new material, step-by-step explanations of the material, as well as offering clear summaries of each lesson.

This textbook's modularity is really quite good. Its language and structure are not overly convoluted or too-lengthy, making it convenient for individual instructors to adapt the materials to suit their methodological preferences.

The topics in the textbook are presented in a logical and clear fashion. The structure of the chapters are such that it is not necessary to have to follow the chapters in their sequential order, and coverage of material can be adapted to individual instructor's preferences.

The textbook is free of any problematic interface issues. Topics, sections and specific content are accessible and easy to navigate. Overall it is user-friendly.

I did not find any significant grammatical issues with the textbook.

The textbook is not culturally insensitive, making use of a diversity of inclusive examples. Materials are especially effective for first-year critical thinking/logic students.

I intend to adopt Van Cleave's textbook for a Critical Thinking class I am teaching at the Community College level. I believe that it will help me facilitate student-learning, and will be a good resource to build additional classroom activities from the materials it provides.

Reviewed by Jennie Harrop, Chair, Department of Professional Studies, George Fox University on 3/27/18

While the book is admirably comprehensive, its extensive details within a few short chapters may feel overwhelming to students. The author tackles an impressive breadth of concepts in Chapter 1, 2, 3, and 4, which leads to 50-plus-page chapters... read more

While the book is admirably comprehensive, its extensive details within a few short chapters may feel overwhelming to students. The author tackles an impressive breadth of concepts in Chapter 1, 2, 3, and 4, which leads to 50-plus-page chapters that are dense with statistical analyses and critical vocabulary. These topics are likely better broached in manageable snippets rather than hefty single chapters.

The ideas addressed in Introduction to Logic and Critical Thinking are accurate but at times notably political. While politics are effectively used to exemplify key concepts, some students may be distracted by distinct political leanings.

The terms and definitions included are relevant, but the examples are specific to the current political, cultural, and social climates, which could make the materials seem dated in a few years without intentional and consistent updates.

While the reasoning is accurate, the author tends to complicate rather than simplify -- perhaps in an effort to cover a spectrum of related concepts. Beginning readers are likely to be overwhelmed and under-encouraged by his approach.

Consistency rating: 3

The four chapters are somewhat consistent in their play of definition, explanation, and example, but the structure of each chapter varies according to the concepts covered. In the third chapter, for example, key ideas are divided into sub-topics numbering from 3.1 to 3.10. In the fourth chapter, the sub-divisions are further divided into sub-sections numbered 4.1.1-4.1.5, 4.2.1-4.2.2, and 4.3.1 to 4.3.6. Readers who are working quickly to master new concepts may find themselves mired in similarly numbered subheadings, longing for a grounded concepts on which to hinge other key principles.

Modularity rating: 3

The book's four chapters make it mostly self-referential. The author would do well to beak this text down into additional subsections, easing readers' accessibility.

The content of the book flows logically and well, but the information needs to be better sub-divided within each larger chapter, easing the student experience.

The book's interface is effective, allowing readers to move from one section to the next with a single click. Additional sub-sections would ease this interplay even further.

Grammatical Errors rating: 4

Some minor errors throughout.

For the most part, the book is culturally neutral, avoiding direct cultural references in an effort to remain relevant.

Reviewed by Yoichi Ishida, Assistant Professor of Philosophy, Ohio University on 2/1/18

This textbook covers enough topics for a first-year course on logic and critical thinking. Chapter 1 covers the basics as in any standard textbook in this area. Chapter 2 covers propositional logic and categorical logic. In propositional logic,... read more

This textbook covers enough topics for a first-year course on logic and critical thinking. Chapter 1 covers the basics as in any standard textbook in this area. Chapter 2 covers propositional logic and categorical logic. In propositional logic, this textbook does not cover suppositional arguments, such as conditional proof and reductio ad absurdum. But other standard argument forms are covered. Chapter 3 covers inductive logic, and here this textbook introduces probability and its relationship with cognitive biases, which are rarely discussed in other textbooks. Chapter 4 introduces common informal fallacies. The answers to all the exercises are given at the end. However, the last set of exercises is in Chapter 3, Section 5. There are no exercises in the rest of the chapter. Chapter 4 has no exercises either. There is index, but no glossary.

The textbook is accurate.

The content of this textbook will not become obsolete soon.

The textbook is written clearly.

The textbook is internally consistent.

The textbook is fairly modular. For example, Chapter 3, together with a few sections from Chapter 1, can be used as a short introduction to inductive logic.

The textbook is well-organized.

There are no interface issues.

I did not find any grammatical errors.

This textbook is relevant to a first semester logic or critical thinking course.

Reviewed by Payal Doctor, Associate Professro, LaGuardia Community College on 2/1/18

This text is a beginner textbook for arguments and propositional logic. It covers the basics of identifying arguments, building arguments, and using basic logic to construct propositions and arguments. It is quite comprehensive for a beginner... read more

This text is a beginner textbook for arguments and propositional logic. It covers the basics of identifying arguments, building arguments, and using basic logic to construct propositions and arguments. It is quite comprehensive for a beginner book, but seems to be a good text for a course that needs a foundation for arguments. There are exercises on creating truth tables and proofs, so it could work as a logic primer in short sessions or with the addition of other course content.

The books is accurate in the information it presents. It does not contain errors and is unbiased. It covers the essential vocabulary clearly and givens ample examples and exercises to ensure the student understands the concepts

The content of the book is up to date and can be easily updated. Some examples are very current for analyzing the argument structure in a speech, but for this sort of text understandable examples are important and the author uses good examples.

The book is clear and easy to read. In particular, this is a good text for community college students who often have difficulty with reading comprehension. The language is straightforward and concepts are well explained.

The book is consistent in terminology, formatting, and examples. It flows well from one topic to the next, but it is also possible to jump around the text without loosing the voice of the text.

The books is broken down into sub units that make it easy to assign short blocks of content at a time. Later in the text, it does refer to a few concepts that appear early in that text, but these are all basic concepts that must be used to create a clear and understandable text. No sections are too long and each section stays on topic and relates the topic to those that have come before when necessary.

The flow of the text is logical and clear. It begins with the basic building blocks of arguments, and practice identifying more and more complex arguments is offered. Each chapter builds up from the previous chapter in introducing propositional logic, truth tables, and logical arguments. A select number of fallacies are presented at the end of the text, but these are related to topics that were presented before, so it makes sense to have these last.

The text is free if interface issues. I used the PDF and it worked fine on various devices without loosing formatting.

1. The book contains no grammatical errors.

The text is culturally sensitive, but examples used are a bit odd and may be objectionable to some students. For instance, President Obama's speech on Syria is used to evaluate an extended argument. This is an excellent example and it is explained well, but some who disagree with Obama's policies may have trouble moving beyond their own politics. However, other examples look at issues from all political viewpoints and ask students to evaluate the argument, fallacy, etc. and work towards looking past their own beliefs. Overall this book does use a variety of examples that most students can understand and evaluate.

My favorite part of this book is that it seems to be written for community college students. My students have trouble understanding readings in the New York Times, so it is nice to see a logic and critical thinking text use real language that students can understand and follow without the constant need of a dictionary.

Reviewed by Rebecca Owen, Adjunct Professor, Writing, Chemeketa Community College on 6/20/17

This textbook is quite thorough--there are conversational explanations of argument structure and logic. I think students will be happy with the conversational style this author employs. Also, there are many examples and exercises using current... read more

This textbook is quite thorough--there are conversational explanations of argument structure and logic. I think students will be happy with the conversational style this author employs. Also, there are many examples and exercises using current events, funny scenarios, or other interesting ways to evaluate argument structure and validity. The third section, which deals with logical fallacies, is very clear and comprehensive. My only critique of the material included in the book is that the middle section may be a bit dense and math-oriented for learners who appreciate the more informal, informative style of the first and third section. Also, the book ends rather abruptly--it moves from a description of a logical fallacy to the answers for the exercises earlier in the text.

The content is very reader-friendly, and the author writes with authority and clarity throughout the text. There are a few surface-level typos (Starbuck's instead of Starbucks, etc.). None of these small errors detract from the quality of the content, though.

One thing I really liked about this text was the author's wide variety of examples. To demonstrate different facets of logic, he used examples from current media, movies, literature, and many other concepts that students would recognize from their daily lives. The exercises in this text also included these types of pop-culture references, and I think students will enjoy the familiarity--as well as being able to see the logical structures behind these types of references. I don't think the text will need to be updated to reflect new instances and occurrences; the author did a fine job at picking examples that are relatively timeless. As far as the subject matter itself, I don't think it will become obsolete any time soon.

The author writes in a very conversational, easy-to-read manner. The examples used are quite helpful. The third section on logical fallacies is quite easy to read, follow, and understand. A student in an argument writing class could benefit from this section of the book. The middle section is less clear, though. A student learning about the basics of logic might have a hard time digesting all of the information contained in chapter two. This material might be better in two separate chapters. I think the author loses the balance of a conversational, helpful tone and focuses too heavily on equations.

Consistency rating: 4

Terminology in this book is quite consistent--the key words are highlighted in bold. Chapters 1 and 3 follow a similar organizational pattern, but chapter 2 is where the material becomes more dense and equation-heavy. I also would have liked a closing passage--something to indicate to the reader that we've reached the end of the chapter as well as the book.

I liked the overall structure of this book. If I'm teaching an argumentative writing class, I could easily point the students to the chapters where they can identify and practice identifying fallacies, for instance. The opening chapter is clear in defining the necessary terms, and it gives the students an understanding of the toolbox available to them in assessing and evaluating arguments. Even though I found the middle section to be dense, smaller portions could be assigned.

The author does a fine job connecting each defined term to the next. He provides examples of how each defined term works in a sentence or in an argument, and then he provides practice activities for students to try. The answers for each question are listed in the final pages of the book. The middle section feels like the heaviest part of the whole book--it would take the longest time for a student to digest if assigned the whole chapter. Even though this middle section is a bit heavy, it does fit the overall structure and flow of the book. New material builds on previous chapters and sub-chapters. It ends abruptly--I didn't realize that it had ended, and all of a sudden I found myself in the answer section for those earlier exercises.

The simple layout is quite helpful! There is nothing distracting, image-wise, in this text. The table of contents is clearly arranged, and each topic is easy to find.

Tiny edits could be made (Starbuck's/Starbucks, for one). Otherwise, it is free of distracting grammatical errors.

This text is quite culturally relevant. For instance, there is one example that mentions the rumors of Barack Obama's birthplace as somewhere other than the United States. This example is used to explain how to analyze an argument for validity. The more "sensational" examples (like the Obama one above) are helpful in showing argument structure, and they can also help students see how rumors like this might gain traction--as well as help to show students how to debunk them with their newfound understanding of argument and logic.

The writing style is excellent for the subject matter, especially in the third section explaining logical fallacies. Thank you for the opportunity to read and review this text!

Reviewed by Laurel Panser, Instructor, Riverland Community College on 6/20/17

This is a review of Introduction to Logic and Critical Thinking, an open source book version 1.4 by Matthew Van Cleave. The comparison book used was Patrick J. Hurley’s A Concise Introduction to Logic 12th Edition published by Cengage as well as... read more

This is a review of Introduction to Logic and Critical Thinking, an open source book version 1.4 by Matthew Van Cleave. The comparison book used was Patrick J. Hurley’s A Concise Introduction to Logic 12th Edition published by Cengage as well as the 13th edition with the same title. Lori Watson is the second author on the 13th edition.

Competing with Hurley is difficult with respect to comprehensiveness. For example, Van Cleave’s book is comprehensive to the extent that it probably covers at least two-thirds or more of what is dealt with in most introductory, one-semester logic courses. Van Cleave’s chapter 1 provides an overview of argumentation including discerning non-arguments from arguments, premises versus conclusions, deductive from inductive arguments, validity, soundness and more. Much of Van Cleave’s chapter 1 parallel’s Hurley’s chapter 1. Hurley’s chapter 3 regarding informal fallacies is comprehensive while Van Cleave’s chapter 4 on this topic is less extensive. Categorical propositions are a topic in Van Cleave’s chapter 2; Hurley’s chapters 4 and 5 provide more instruction on this, however. Propositional logic is another topic in Van Cleave’s chapter 2; Hurley’s chapters 6 and 7 provide more information on this, though. Van Cleave did discuss messy issues of language meaning briefly in his chapter 1; that is the topic of Hurley’s chapter 2.

Van Cleave’s book includes exercises with answers and an index. A glossary was not included.

Reviews of open source textbooks typically include criteria besides comprehensiveness. These include comments on accuracy of the information, whether the book will become obsolete soon, jargon-free clarity to the extent that is possible, organization, navigation ease, freedom from grammar errors and cultural relevance; Van Cleave’s book is fine in all of these areas. Further criteria for open source books includes modularity and consistency of terminology. Modularity is defined as including blocks of learning material that are easy to assign to students. Hurley’s book has a greater degree of modularity than Van Cleave’s textbook. The prose Van Cleave used is consistent.

Van Cleave’s book will not become obsolete soon.

Van Cleave’s book has accessible prose.

Van Cleave used terminology consistently.

Van Cleave’s book has a reasonable degree of modularity.

Van Cleave’s book is organized. The structure and flow of his book is fine.

Problems with navigation are not present.

Grammar problems were not present.

Van Cleave’s book is culturally relevant.

Van Cleave’s book is appropriate for some first semester logic courses.

Table of Contents

Chapter 1: Reconstructing and analyzing arguments

  • 1.1 What is an argument?
  • 1.2 Identifying arguments
  • 1.3 Arguments vs. explanations
  • 1.4 More complex argument structures
  • 1.5 Using your own paraphrases of premises and conclusions to reconstruct arguments in standard form
  • 1.6 Validity
  • 1.7 Soundness
  • 1.8 Deductive vs. inductive arguments
  • 1.9 Arguments with missing premises
  • 1.10 Assuring, guarding, and discounting
  • 1.11 Evaluative language
  • 1.12 Evaluating a real-life argument

Chapter 2: Formal methods of evaluating arguments

  • 2.1 What is a formal method of evaluation and why do we need them?
  • 2.2 Propositional logic and the four basic truth functional connectives
  • 2.3 Negation and disjunction
  • 2.4 Using parentheses to translate complex sentences
  • 2.5 “Not both” and “neither nor”
  • 2.6 The truth table test of validity
  • 2.7 Conditionals
  • 2.8 “Unless”
  • 2.9 Material equivalence
  • 2.10 Tautologies, contradictions, and contingent statements
  • 2.11 Proofs and the 8 valid forms of inference
  • 2.12 How to construct proofs
  • 2.13 Short review of propositional logic
  • 2.14 Categorical logic
  • 2.15 The Venn test of validity for immediate categorical inferences
  • 2.16 Universal statements and existential commitment
  • 2.17 Venn validity for categorical syllogisms

Chapter 3: Evaluating inductive arguments and probabilistic and statistical fallacies

  • 3.1 Inductive arguments and statistical generalizations
  • 3.2 Inference to the best explanation and the seven explanatory virtues
  • 3.3 Analogical arguments
  • 3.4 Causal arguments
  • 3.5 Probability
  • 3.6 The conjunction fallacy
  • 3.7 The base rate fallacy
  • 3.8 The small numbers fallacy
  • 3.9 Regression to the mean fallacy
  • 3.10 Gambler's fallacy

Chapter 4: Informal fallacies

  • 4.1 Formal vs. informal fallacies
  • 4.1.1 Composition fallacy
  • 4.1.2 Division fallacy
  • 4.1.3 Begging the question fallacy
  • 4.1.4 False dichotomy
  • 4.1.5 Equivocation
  • 4.2 Slippery slope fallacies
  • 4.2.1 Conceptual slippery slope
  • 4.2.2 Causal slippery slope
  • 4.3 Fallacies of relevance
  • 4.3.1 Ad hominem
  • 4.3.2 Straw man
  • 4.3.3 Tu quoque
  • 4.3.4 Genetic
  • 4.3.5 Appeal to consequences
  • 4.3.6 Appeal to authority

Answers to exercises Glossary/Index

Ancillary Material

About the book.

This is an introductory textbook in logic and critical thinking. The goal of the textbook is to provide the reader with a set of tools and skills that will enable them to identify and evaluate arguments. The book is intended for an introductory course that covers both formal and informal logic. As such, it is not a formal logic textbook, but is closer to what one would find marketed as a “critical thinking textbook.”

About the Contributors

Matthew Van Cleave ,   PhD, Philosophy, University of Cincinnati, 2007.  VAP at Concordia College (Moorhead), 2008-2012.  Assistant Professor at Lansing Community College, 2012-2016. Professor at Lansing Community College, 2016-

Contribute to this Page

Logo for OPEN OKSTATE

3 Fallacies

I. what a re fallacies 1.

Fallacies are mistakes of reasoning, as opposed to making mistakes that are of a factual nature. If I counted twenty people in the room when there were in fact twenty-one, then I made a factual mistake. On the other hand, if I believe that there are round squares I believe something that is contradictory. A belief in “round squares” is a mistake of reasoning and contains a fallacy because, if my reasoning were good, I would not believe something that is logically inconsistent with reality.

In some discussions, a fallacy is taken to be an undesirable kind of argument or inference. In our view, this definition of fallacy is rather narrow, since we might want to count certain mistakes of reasoning as fallacious even though they are not presented as arguments. For example, making a contradictory claim seems to be a case of fallacy, but a single claim is not an argument. Similarly, putting forward a question with an inappropriate presupposition might also be regarded as a fallacy, but a question is also not an argument. In both of these situations though, the person is making a mistake of reasoning since they are doing something that goes against one or more principles of correct reasoning. This is why we would like to define fallacies more broadly as violations of the principles of critical thinking , whether or not the mistakes take the form of an argument.

The study of fallacies is an application of the principles of critical thinking. Being familiar with typical fallacies can help us avoid them and help explain other people’s mistakes.

There are different ways of classifying fallacies. Broadly speaking, we might divide fallacies into four kinds:

  • Fallacies of inconsistency: cases where something inconsistent or self-defeating has been proposed or accepted.
  • Fallacies of relevance: cases where irrelevant reasons are being invoked or relevant reasons being ignored.
  • Fallacies of insufficiency: cases where the evidence supporting a conclusion is insufficient or weak.
  • Fallacies of inappropriate presumption: cases where we have an assumption or a question presupposing something that is not reasonable to accept in the relevant conversational context.

II. Fallacies of I nconsistency

Fallacies of inconsistency are cases where something inconsistent, self-contradictory or self-defeating is presented.

1. Inconsistency

Here are some examples:

  • “One thing that we know for certain is that nothing is ever true or false.” – If there is something we know for certain, then there is at least one truth that we know. So it can’t be the case that nothing is true or false.
  • “Morality is relative and is just a matter of opinion, and so it is always wrong to impose our opinions on other people.” – But if morality is relative, it is also a relative matter whether we should impose our opinions on other people. If we should not do that, there is at least one thing that is objectively wrong.
  • “All general claims have exceptions.” – This claim itself is a general claim, and so if it is to be regarded as true we must presuppose that there is an exception to it, which would imply that there exists at least one general claim that does not have an exception. So the claim itself is inconsistent.

2. Self- D efeating C laims

A self-defeating statement is a statement that, strictly speaking, is not logically inconsistent but is instead obviously false. Consider these examples:

  • Very young children are fond of saying “I am not here” when they are playing hide-and-seek. The statement itself is not logically consistent, since it is not logically possible for the child not to be where she is. What is impossible is to  utter the sentence as a true sentence  (unless it is used for example in a telephone recorded message.)
  • Someone who says, “I cannot speak any English.”
  • Here is an actual example: A TV program in Hong Kong was critical of the Government. When the Hong Kong Chief Executive Mr. Tung was asked about it, he replied, “I shall not comment on such distasteful programs.” Mr. Tung’s remark was not logically inconsistent, because what it describes is a possible state of affairs. But it is nonetheless self-defeating because calling the program “distasteful” is to pass a comment!

III. Fallacies of R elevance

1. taking irrelevant considerations into account.

This includes defending a conclusion by appealing to irrelevant reasons, e.g., inappropriate appeal to pity, popular opinion, tradition, authority, etc. An example would be when a student failed a course and asked the teacher to give him a pass instead, because “his parents will be upset.” Since grades should be given on the basis of performance, the reason being given is quite irrelevant.

Similarly, suppose someone criticizes the Democratic Party’s call for direct elections in Hong Kong as follows: “These arguments supporting direct elections have no merit because they are advanced by Democrats who naturally stand to gain from it.” This is again fallacious because whether the person advancing the argument has something to gain from direct elections is a completely different issue from whether there ought to be direct elections.

2. Failing to T ake R elevant C onsiderations into A ccount

For example, it is not unusual for us to ignore or downplay criticisms because we do not like them, even when those criticisms are justified. Or sometimes we might be tempted to make a snap decision, believing knee-jerk reactions are the best when, in fact, we should be investigating the situation more carefully and doing more research.

Of course, if we fail to consider a relevant fact simply because we are ignorant of it, then this lack of knowledge does not constitute a fallacy.

IV. Fallacies of Insufficiency

Fallacies of insufficiency are cases where insufficient evidence is provided in support of a claim. Most common fallacies fall within this category. Here are a few popular types:

1. Limited S ampling

  • Momofuku Ando, the inventor of instant noodles, died at the age of 96. He said he ate instant noodles every day. So instant noodles cannot be bad for your health.
  • A black cat crossed my path this morning, and I got into a traffic accident this afternoon. Black cats are really unlucky.

In both cases the observations are relevant to the conclusion, but a lot more data is needed to support the conclusion, e.g., studies show that many other people who eat instant noodles live longer, and those who encounter black cats are more likely to suffer from accidents.

2. Appeal to I gnorance

  • We have no evidence showing that he is innocent. So he must be guilty.

If someone is guilty, it would indeed be hard to find evidence showing that he is innocent. But perhaps there is no evidence to point either way, so a lack of evidence is not enough to prove guilt.

3. Naturalistic F allacy

  • Many children enjoy playing video games, so we should not stop them from playing.

Many naturalistic fallacies are examples of fallacy of insufficiency. Empirical facts by themselves are not sufficient for normative conclusions, even if they are relevant.

There are many other kinds of fallacy of insufficiency. See if you can identify some of them.

V. Fallacies of Inappropriate Presumption

Fallacies of inappropriate presumption are cases where we have explicitly or implicitly made an assumption that is not reasonable to accept in the relevant context. Some examples include:

  • Many people like to ask whether human nature is good or evil. This presupposes that there is such a thing as human nature and that it must be either good or bad. But why should these assumptions be accepted, and are they the only options available? What if human nature is neither good nor bad? Or what if good or bad nature applies only to individual human beings?
  • Consider the question “Have you stopped being an idiot?” Whether you answer “yes” or “no,” you admit that you are, or have been, an idiot. Presumably you do not want to make any such admission. We can point out that this question has a false assumption.
  • “Same-sex marriage should not be allowed because by definition a marriage should be between a man and a woman.” This argument assumes that only a heterosexual conception of marriage is correct. But this begs the question against those who defend same-sex marriages and is not an appropriate assumption to make when debating this issue.

VI. List of Common Fallacies

A theory is discarded not because of any evidence against it or lack of evidence for it, but because of the person who argues for it. Example:

A: The Government should enact minimum-wage legislation so that workers are not exploited. B: Nonsense. You say that only because you cannot find a good job.

ad ignorantiam (appeal to ignorance)

The truth of a claim is established only on the basis of lack of evidence against it. A simple obvious example of such fallacy is to argue that unicorns exist because there is no evidence against their existence. At first sight it seems that many theories that we describe as “scientific” involve such a fallacy. For example, the first law of thermodynamics holds because so far there has not been any negative instance that would serve as evidence against it. But notice, as in cases like this, there is evidence for the law, namely positive instances. Notice also that this fallacy does not apply to situations where there are only two rival claims and one has already been falsified. In situations such as this, we may justly establish the truth of the other even if we cannot find evidence for or against it.

ad misericordiam (appeal to pity)

In offering an argument, pity is appealed to. Usually this happens when people argue for special treatment on the basis of their need, e.g., a student argues that the teacher should let them pass the examination because they need it in order to graduate. Of course, pity might be a relevant consideration in certain conditions, as in contexts involving charity.

ad populum (appeal to popularity)

The truth of a claim is established only on the basis of its popularity and familiarity. This is the fallacy committed by many commercials. Surely you have heard of commercials implying that we should buy a certain product because it has made to the top of a sales rank, or because the brand is the city’s “favorite.”

Affirming the consequent

Inferring that P is true solely because Q is true and it is also true that if P is true, Q is true.

The problem with this type of reasoning is that it ignores the possibility that there are other conditions apart from P that might lead to Q. For example, if there is a traffic jam, a colleague may be late for work. But if we argue from his being late to there being a traffic jam, we are guilty of this fallacy – the colleague may be late due to a faulty alarm clock.

Of course, if we have evidence showing that P is the only or most likely condition that leads to Q, then we can infer that P is likely to be true without committing a fallacy.

Begging the question ( petito principii )

In arguing for a claim, the claim itself is already assumed in the premise. Example: “God exists because this is what the Bible says, and the Bible is reliable because it is the word of God.”

Complex question or loaded question

A question is posed in such a way that a person, no matter what answer they give to the question, will inevitably commit themselves to some other claim, which should not be presupposed in the context in question.

A common tactic is to ask a yes-no question that tricks people into agreeing to something they never intended to say. For example, if you are asked, “Are you still as self-centered as you used to be?”, no matter whether you answer “yes” or ”no,” you are bound to admit that you were self-centered in the past. Of course, the same question would not count as a fallacy if the presupposition of the question were indeed accepted in the conversational context, i.e., that the person being asked the question had been verifiably self-centered in the past.

Composition (opposite of division)

The whole is assumed to have the same properties as its parts. Anne might be humorous and fun-loving and an excellent person to invite to the party. The same might be true of Ben, Chris and David, considered individually. But it does not follow that it will be a good idea to invite all of them to the party. Perhaps they hate each other and the party will be ruined.

Denying the antecedent

Inferring that Q is false just because if P is true, Q is also true, but P is false.

This fallacy is similar to the fallacy of affirming the consequent. Again the problem is that some alternative explanation or cause might be overlooked. Although P is false, some other condition might be sufficient to make Q true.

Example: If there is a traffic jam, a colleague may be late for work. But it is not right to argue in the light of smooth traffic that the colleague will not be late. Again, his alarm clock may have stopped working.

Division (opposite of composition)

The parts of a whole are assumed to have the same properties as the whole. It is possible that, on a whole, a company is very effective, while some of its departments are not. It would be inappropriate to assume they all are.

Equivocation

Putting forward an argument where a word changes meaning without having it pointed out. For example, some philosophers argue that all acts are selfish. Even if you strive to serve others, you are still acting selfishly because your act is just to satisfy your desire to serve others. But surely the word “selfish” has different meanings in the premise and the conclusion – when we say a person is selfish we usually mean that he does not strive to serve others. To say that a person is selfish because he is doing something he wants, even when what he wants is to help others, is to use the term “selfish” with a different meaning.

False dilemma

Presenting a limited set of alternatives when there are others that are worth considering in the context. Example: “Every person is either my enemy or my friend. If they are my enemy, I should hate them. If they’re my friend, I should love them. So I should either love them or hate them.” Obviously, the conclusion is too extreme because most people are neither your enemy nor your friend.

Gambler’s fallacy

Assumption is made to take some independent statistics as dependent. The untrained mind tends to think that, for example, if a fair coin is tossed five times and the results are all heads, then the next toss will more likely be a tail. It will not be, however. If the coin is fair, the result for each toss is completely independent of the others. Notice the fallacy hinges on the fact that the final result is not known. Had the final result been known already, the statistics would have been dependent.

Genetic fallacy

Thinking that because X derives from Y, and because Y has a certain property, that X must also possess that same property. Example: “His father is a criminal, so he must also be up to no good.”

Non sequitur

A conclusion is drawn that does not follow from the premise. This is not a specific fallacy but a very general term for a bad argument. So a lot of the examples above and below can be said to be non sequitur.

Post hoc, ergo propter hoc  (literally, “ after this, therefore because of this ” )

Inferring that X must be the cause of Y just because X is followed by Y.

For example, having visited a graveyard, I fell ill and infer that graveyards are spooky places that cause illnesses. Of course, this inference is not warranted since this might just be a coincidence. However, a lot of superstitious beliefs commit this fallacy.

Red herring

Within an argument some irrelevant issue is raised that diverts attention from the main subject. The function of the red herring is sometimes to help express a strong, biased opinion. The red herring (the irrelevant issue) serves to increase the force of the argument in a very misleading manner.

For example, in a debate as to whether God exists, someone might argue that believing in God gives peace and meaning to many people’s lives. This would be an example of a red herring since whether religions can have a positive effect on people is irrelevant to the question of the existence of God. The positive psychological effect of a belief is not a reason for thinking that the belief is true.

Slippery slope

Arguing that if an opponent were to accept some claim C 1 , then they have to accept some other closely related claim C 2 , which in turn commits the opponent to a still further claim C 3 , eventually leading to the conclusion that the opponent is committed to something absurd or obviously unacceptable.

This style of argumentation constitutes a fallacy only when it is inappropriate to think if one were to accept the initial claim, one must accept all the other claims.

An example: “The government should not prohibit drugs. Otherwise the government should also ban alcohol or cigarettes. And then fatty food and junk food would have to be regulated too. The next thing you know, the government would force us to brush our teeth and do exercises every day.”

Attacking an opponent while falsely attributing to them an implausible position that is easily defeated.

Example: When many people argue for more democracy in Hong Kong, a typical “straw man” reply is to say that more democracy is not warranted because it is wrong to believe that democracy is the solution to all of Hong Kong’s problems. But those who support more democracy in Hong Kong never suggest that democracy can solve  all  problems (e.g., pollution), and those who support more democracy in Hong Kong might even agree that  blindly  accepting anything is rarely the correct course of action, whether it is democracy or not. Theses criticisms attack implausible “straw man” positions and do not address the real arguments for democracy.

Suppressed evidence

Where there is contradicting evidence, only confirming evidence is presented.

VII. Exercises

Identify any fallacy in each of these passages. If no fallacy is committed, select “no fallacy involved.”

1. Mr. Lee’s views on Japanese culture are wrong. This is because his parents were killed by the Japanese army during World War II and that made him anti-Japanese all his life.

2. Every ingredient of this soup is tasty. So this must be a very tasty soup.

3. Smoking causes cancer because my father was a smoker and he died of lung cancer.

4. Professor Lewis, the world authority on logic, claims that all wives cook for their husbands. But the fact is that his own wife does not cook for him. Therefore, his claim is false.

5. If Catholicism is right, then no women should be allowed to be priests. But Catholicism is wrong. Therefore, some women should be allowed to be priests.

6. God does not exist because every argument for the existence of God has been shown to be unsound.

7. The last three times I have had a cold I took large doses of vitamin C. On each occasion, the cold cleared up within a few days. So vitamin C helped me recover from colds.

8. The union’s case for more funding for higher education can be ignored because it is put forward by the very people – university staff – who would benefit from the increased money.

9. Children become able to solve complex problems and think of physical objects objectively at the same time that they learn language. Therefore, these abilities are caused by learning a language.

10. If cheap things are no good then this cheap watch is no good. But this watch is actually quite good. So some good things are cheap.

Critical Thinking Copyright © 2019 by Brian Kim is licensed under a Creative Commons Attribution 4.0 International License , except where otherwise noted.

Share This Book

Everyday Psychology. Critical Thinking and Skepticism.

What are Logical Fallacies? | Critical Thinking Basics

Logical fallacies are errors in reasoning or flawed arguments that can mislead or deceive. They often appear plausible but lack sound evidence or valid reasoning, undermining the credibility of an argument. These errors can be categorized into various types, such as ad hominem attacks, strawman arguments, and false cause correlations.

Impact on Critical Thinking, Communication, and Social Interactions

The presence of logical fallacies hampers critical thinking by leading individuals away from rational and evidence-based conclusions. In communication, they can create confusion, weaken the persuasiveness of an argument, and hinder the exchange of ideas.

In social interactions, reliance on fallacious reasoning can strain relationships, impede collaboration, and contribute to misunderstandings.

Benefits of Identifying and Managing Logical Fallacies

Learning to identify logical fallacies enhances critical thinking skills, enabling individuals to analyze arguments more effectively and make informed decisions. In communication, recognizing fallacies empowers individuals to construct more compelling and convincing arguments, fostering clearer and more meaningful exchanges.

Moreover, the ability to manage logical fallacies promotes healthier social interactions by minimizing misunderstandings, encouraging constructive dialogue, and fostering a more intellectually robust and collaborative environment.

RETURN TO THE MAIN RESOURCE PAGE: CRITICAL THINKING BASICS

Share this:

Jessie Ball duPont Library

Critical thinking skills, watch the fallacies.

  • Need Research Help?
  • Research Help

Profile Photo

Although there are more than two dozen types and subtypes of logical fallacies, these are the most common forms that you may encounter in writing, argument, and daily life:

Example: Special education students should not be required to take standardized tests because such tests are meant for nonspecial education students.
Example: Two out of three patients who were given green tea before bedtime reported sleeping more soundly. Therefore, green tea may be used to treat insomnia.
  • Sweeping generalizations  are related to the problem of hasty generalizations. In the former, though, the error consists in assuming that a particular conclusion drawn from a particular situation and context applies to all situations and contexts. For example, if I research a particular problem at a private performing arts high school in a rural community, I need to be careful not to assume that my findings will be generalizable to all high schools, including public high schools in an inner city setting.
Example: Professor Berger has published numerous articles in immunology. Therefore, she is an expert in complementary medicine.
Example: Drop-out rates increased the year after NCLB was passed. Therefore, NCLB is causing kids to drop out.
Example: Japanese carmakers must implement green production practices, or Japan‘s carbon footprint will hit crisis proportions by 2025.

In addition to claims of policy, false dilemma seems to be common in claims of value. For example, claims about abortion‘s morality (or immorality) presuppose an either-or about when "life" begins. Our earlier example about sustainability (―Unsustainable business practices are unethical.‖) similarly presupposes an either/or: business practices are either ethical or they are not, it claims, whereas a moral continuum is likelier to exist.

Begging the Question/Circular Reasoning

Hasty Generalization

Sweeping Generalization

Non Sequitur

Post Hoc Ergo Propter Hoc

False Dilemma

  • << Previous: Abduction
  • Next: Need Research Help? >>
  • Last Updated: Jul 28, 2020 5:53 PM
  • URL: https://library.sewanee.edu/critical_thinking

Research Tools

  • Find Articles
  • Find Research Guides
  • Find Databases
  • Ask a Librarian
  • Learn Research Skills
  • How-To Videos
  • Borrow from Another Library (Sewanee ILL)
  • Find Audio and Video
  • Find Reserves
  • Access Electronic Resources

Services for...

  • College Students
  • The School of Theology
  • The School of Letters
  • Community Members

Spaces & Places

  • Center for Leadership
  • Center for Speaking and Listening
  • Center for Teaching
  • Floor Maps & Locations
  • Ralston Listening Library
  • Study Spaces
  • Tech Help Desk
  • Writing Center

About the Library

  • Where is the Library?
  • Library Collections
  • New Items & Themed Collections
  • Library Policies
  • Library Staff
  • Friends of the Library

Jessie Ball duPont Library, University of the South

178 Georgia Avenue, Sewanee, TN 37383

931.598.1664

Logo for M Libraries Publishing

Want to create or adapt books like this? Learn more about how Pressbooks supports open publishing practices.

11.3 Persuasive Reasoning and Fallacies

Learning objectives.

  • Define inductive, deductive, and causal reasoning.
  • Evaluate the quality of inductive, deductive, and causal reasoning.
  • Identify common fallacies of reasoning.

Persuasive speakers should be concerned with what strengthens and weakens an argument. Earlier we discussed the process of building an argument with claims and evidence and how warrants are the underlying justifications that connect the two. We also discussed the importance of evaluating the strength of a warrant, because strong warrants are usually more persuasive. Knowing different types of reasoning can help you put claims and evidence together in persuasive ways and help you evaluate the quality of arguments that you encounter. Further, being able to identify common fallacies of reasoning can help you be a more critical consumer of persuasive messages.

Reasoning refers to the process of making sense of things around us. In order to understand our experiences, draw conclusions from information, and present new ideas, we must use reasoning. We often reason without being aware of it, but becoming more aware of how we think can empower us to be better producers and consumers of communicative messages. The three types of reasoning we will explore are inductive, deductive, and causal.

Inductive Reasoning

Inductive reasoning reaches conclusions through the citation of examples and is the most frequently used form of logical reasoning (Walter, 1966). While introductory speakers are initially attracted to inductive reasoning because it seems easy, it can be difficult to employ well. Inductive reasoning, unlike deductive reasoning, doesn’t result in true or false conclusions. Instead, since conclusions are generalized based on observations or examples, conclusions are “more likely” or “less likely.” Despite the fact that this type of reasoning isn’t definitive, it can still be valid and persuasive.

Some arguments based on inductive reasoning will be more cogent, or convincing and relevant, than others. For example, inductive reasoning can be weak when claims are made too generally. An argument that fraternities should be abolished from campus because they contribute to underage drinking and do not uphold high academic standards could be countered by providing examples of fraternities that sponsor alcohol education programming for the campus and have members that have excelled academically (Walter, 1966). In this case, one overly general claim is countered by another general claim, and both of them have some merit. It would be more effective to present a series of facts and reasons and then share the conclusion or generalization that you have reached from them.

You can see inductive reasoning used in the following speech excerpt from President George W. Bush’s address to the nation on the evening of September 11, 2001. Notice how he lists a series of events from the day, which builds to his conclusion that the terrorist attacks failed in their attempt to shake the foundation of America.

Today, our fellow citizens, our way of life, our very freedom came under attack in a series of deliberate and deadly terrorist acts. The victims were in airplanes or in their offices: secretaries, business men and women, military and federal workers, moms and dads, friends and neighbors. Thousands of lives were suddenly ended by evil, despicable acts of terror. The pictures of airplanes flying into buildings, fires burning, huge—huge structures collapsing have filled us with disbelief, terrible sadness, and a quiet, unyielding anger. These acts of mass murder were intended to frighten our nation into chaos and retreat. But they have failed. Our country is strong. A great people has been moved to defend a great nation. Terrorist attacks can shake the foundations of our biggest buildings, but they cannot touch the foundation of America.

11.3.0N

Using inductive reasoning, speakers reach conclusions through the citation of examples.

Claire Sambrook – UM… – CC BY-NC 2.0.

If a speaker is able to provide examples that are concrete, proxemic, and relevant to the audience, as Bush did in this example, audience members are prompted to think of additional examples that connect to their own lives. Inductive reasoning can be useful when an audience disagrees with your proposition. As you present logically connected examples as evidence that build to a conclusion, the audience may be persuaded by your evidence before they realize that the coming conclusion will counter what they previously thought. This also sets up cognitive dissonance, which is a persuasive strategy we will discuss later.

Reasoning by analogy is a type of inductive reasoning that argues that what is true in one set of circumstances will be true in another (Walter, 1966). Reasoning by analogy has been criticized and questioned by logicians, since two sets of circumstances are never exactly the same. While this is true, our goal when using reasoning by analogy in persuasive speaking is not to create absolutely certain conclusions but to cite cases and supporting evidence that can influence an audience. For example, let’s say you are trying to persuade a university to adopt an alcohol education program by citing the program’s success at other institutions. Since two universities are never exactly the same, the argument can’t be airtight. To better support this argument, you could first show that the program was actually successful using various types of supporting material such as statistics from campus offices and testimony from students and staff. Second, you could show how the cases relate by highlighting similarities in the campus setting, culture, demographics, and previous mission. Since you can’t argue that the schools are similar in all ways, choose to highlight significant similarities. Also, it’s better to acknowledge significant limitations of the analogy and provide additional supporting material to address them than it is to ignore or hide such limitations.

So how do we evaluate inductive reasoning? When inductive reasoning is used to test scientific arguments, there is rigorous testing and high standards that must be met for a conclusion to be considered valid. Inductive reasoning in persuasive speaking is employed differently. A speaker cannot cite every example that exists to build to a conclusion, so to evaluate inductive reasoning you must examine the examples that are cited in ways other than quantity. First, the examples should be sufficient, meaning that enough are cited to support the conclusion. If not, you risk committing the hasty generalization fallacy. A speaker can expect that the audience will be able to think of some examples as well, so there is no set number on how many examples is sufficient. If the audience is familiar with the topic, then fewer examples are probably sufficient, while more may be needed for unfamiliar topics. A speaker can make his or her use of reasoning by example more powerful by showing that the examples correspond to the average case, which may require additional supporting evidence in the form of statistics. Arguing that teacher salaries should be increased by providing an example of a teacher who works side jobs and pays for his or her own school supplies could be effectively supported by showing that this teacher’s salary corresponds to the national average (Walter, 1966).

Second, the examples should be typical, meaning they weren’t cherry-picked to match the point being argued. A speaker who argues to defund the National Endowment for the Arts (NEA) because the organization supports art that is “pornographic and offensive” may cite five examples of grants given for projects that caused such controversy. Failing to mention that these examples were pulled from the more than 128,000 grants issued by the NEA would be an inappropriate use of inductive reasoning since the examples aren’t sufficient or typical enough to warrant the argument. Another way to support inductive arguments is to show that the examples are a fair sample, meaning they are representative of the larger whole. Arguing that college athletes shouldn’t receive scholarships because they do not have the scholastic merit of other students and have less academic achievement could be supported by sharing several examples. But if those examples were not representative, then they are biased, and the reasoning faulty. A speaker would need to show that the athletes used in the example are representative, in terms of their race, gender, sport, and background, of the population of athletes at the university.

Deductive Reasoning

Deductive reasoning derives specifics from what is already known. It was the preferred form of reasoning used by ancient rhetoricians like Aristotle to make logical arguments (Cooper & Nothstine, 1996). A syllogism is an example of deductive reasoning that is commonly used when teaching logic. A syllogism is an example of deductive reasoning in which a conclusion is supported by major and minor premises. The conclusion of a valid argument can be deduced from the major and minor premises. A commonly used example of a syllogism is “All humans are mortal. Socrates is a human. Socrates is mortal.” In this case, the conclusion, “Socrates is mortal,” is derived from the major premise, “All humans are mortal,” and the minor premise, “Socrates is a human.” In some cases, the major and minor premises of a syllogism may be taken for granted as true. In the previous example, the major premise is presumed true because we have no knowledge of an immortal person to disprove the statement. The minor premise is presumed true because Socrates looks and acts like other individuals we know to be human. Detectives or scientists using such logic would want to test their conclusion. We could test our conclusion by stabbing Socrates to see if he dies, but since the logic of the syllogism is sound, it may be better to cut Socrates a break and deem the argument valid. Since most arguments are more sophisticated than the previous example, speakers need to support their premises with research and evidence to establish their validity before deducing their conclusion.

A syllogism can lead to incorrect conclusions if one of the premises isn’t true, as in the following example:

  • All presidents have lived in the White House. (Major premise)
  • George Washington was president. (Minor premise)
  • George Washington lived in the White House. (Conclusion)

In the previous example, the major premise was untrue, since John Adams, our second president, was the first president to live in the White House. This causes the conclusion to be false. A syllogism can also exhibit faulty logic even if the premises are both true but are unrelated, as in the following example:

  • Penguins are black and white. (Major premise)
  • Some old television shows are black and white. (Minor premise)
  • Some penguins are old television shows. (Conclusion)

11.3.1N

Like in the game of Clue, real-life detectives use deductive reasoning to draw a conclusion about who committed a crime based on the known evidence.

Sleepmyf – Lego detective – CC BY-NC-ND 2.0.

Causal Reasoning

Causal reasoning argues to establish a relationship between a cause and an effect. When speakers attempt to argue for a particular course of action based on potential positive or negative consequences that may result, they are using causal reasoning. Such reasoning is evident in the following example: Eating more local foods will boost the local economy and make you healthier. The “if/then” relationship that is set up in causal reasoning can be persuasive, but the reasoning isn’t always sound. Rather than establishing a true cause-effect relationship, speakers more often set up a correlation, which means there is a relationship between two things but there are other contextual influences.

To use causal reasoning effectively and ethically, speakers should avoid claiming a direct relationship between a cause and an effect when such a connection cannot be proven. Instead of arguing that “x caused y,” it is more accurate for a speaker to say “x influenced y.” Causal thinking is often used when looking to blame something or someone, as can be seen in the following example: It’s the president’s fault that the economy hasn’t recovered more. While such a statement may garner a speaker some political capital, it is not based on solid reasoning. Economic and political processes are too complex to distill to such a simple cause-effect relationship. A speaker would need to use more solid reasoning, perhaps inductive reasoning through examples, to build up enough evidence to support that a correlation exists and a causal relationship is likely. When using causal reasoning, present evidence that shows the following: (1) the cause occurred before the effect, (2) the cause led to the effect, and (3) it is unlikely that other causes produced the effect.

Review of Types of Reasoning

  • Inductive. Arguing from examples to support a conclusion; includes reasoning by analogy. Examples should be sufficient, typical, and representative to warrant a strong argument.
  • Deductive. Deriving specifics from what is already known; includes syllogisms. Premises that lead to a conclusion must be true, relevant, and related for the argument to be valid.
  • Causal. Argues to establish a relationship between a cause and an effect. Usually involves a correlation rather than a true causal relationship.

Fallacies of Reasoning

Fallacies are flaws within the logic or reasoning of an argument. Although we will discuss 10 common fallacies, more than 125 have been identified and named. It’s important to note that the presence of a fallacy in an argument doesn’t mean that it can’t be persuasive. In fact, many people are persuaded by fallacious arguments because they do not identify the fallacy within the argument. Fallacies are often the last effort of uninformed or ill-prepared speakers who find that they have nothing better to say. Being aware of the forms of reasoning and fallacies makes us more critical consumers of persuasive messages, which is a substantial benefit of studying persuasive speaking that affects personal, political, and professional aspects of our lives.

Hasty Generalization

The hasty generalization fallacy relates to inductive reasoning and is the result of too few examples being cited to warrant the generalization. Jumping to conclusions is tempting, especially when pressed for time, but making well-researched and supported arguments is key to being an effective and ethical speaker. Making a claim that train travel is not safe and citing two recent derailments that resulted in injury doesn’t produce a strong warrant when viewed in relation to the number of train passengers who travel safely every day.

False Analogy

The false analogy fallacy also relates to inductive reasoning and results when the situations or circumstances being compared are not similar enough. A common false analogy that people make is comparing something to putting a person on the moon: “If we can put a person on the moon, why can’t we figure out a way to make the tax code easier to understand?” This question doesn’t acknowledge the different skill sets and motivations involved in the two examples being compared.

False Cause

The false cause fallacy relates to causal reasoning and occurs when a speaker argues, with insufficient evidence, that one thing caused or causes another. When I was in high school, teachers used to say that wearing baseball caps would make us go bald when we got older. In an attempt to persuade us to not wear hats in the classroom, they were arguing, fallaciously, that wearing baseball caps is what causes baldness. When a false cause argument is made after the “effect,” it is referred to in Latin as post hoc ergo propter hoc , which means “after this, therefore because of this.” Blaming bad fortune on superstitions is a good example of faulty reasoning that tries to argue for a connection between an “effect” that has already occurred and its preceding “cause.” My bad luck is more likely attributable to poor decisions I have made or random interference than the mirror I broke while moving two years ago.

11.3.2N

Superstitious beliefs often exemplify the false cause fallacy. Is the broken mirror really the cause of your bad luck?

Tim Sheerman-Chase – Seven Years Bad Luck – CC BY 2.0.

False Authority

The false authority fallacy results when the person making an argument doesn’t actually have the qualifications to be credible but is perceived as credible because they are respected or admired. Despite the fact that this form of argument is fallacious, it is obviously quite effective. Advertisers spend millions of dollars to get celebrities and athletes to sell us their products because of the persuasive potential these stars carry in their persona, not in their ability to argue a point. Voters might be persuaded to support a candidate because of a famous musician’s endorsement without questioning the political beliefs of either the musician or the politician to see if they match up with their own.

Parents and other sources of guidance in our lives have tried to keep us from falling for the bandwagon fallacy. When your mom responds to your argument that you should get to go to the party because everyone else is by asking, “If everyone else jumped off a bridge, would you?” she is rightfully pointing out the fallacy in your argument. In a public-speaking-related example, I have had students try to persuade their audience to buy and eat more organic foods based on their increasing popularity. In short, popular appeal and frequency of use are not strong warrants to support an argument. Just because something is popular, doesn’t mean it’s good.

False Dilemma

The false dilemma fallacy occurs when a speaker rhetorically backs his or her audience into a corner, presenting them with only two options and arguing that they must choose either one or the other. This is also known as the “either/or” fallacy. Critical thinkers know that the world can’t be simplified to black and white, good and bad, or right and wrong. Yet many people rely on such oversimplifications when making arguments. A speaker who argues that immigrants to the United States should learn English or go back to their own country doesn’t acknowledge that there are many successful immigrants who have successful lives and contribute to society without speaking English fluently. The speaker also ignores the fact that many immigrants do not have access to English language instruction or the time to take such classes because they are busy with their own jobs and families. Granted, such a rhetorical strategy does make it easier to discuss complex issues and try to force people into a decision, but it also removes gray area in the form of context that can be really important for making a decision. Be critical of speakers and messages that claim there are only two options from which to choose.

Ad hominem means “to the person” in Latin and refers to a common fallacy of attacking a person rather than an argument. Elementary school playgrounds and middle school hallways are often sites of ad hominem attacks. When one person runs out of good reasons to support their argument and retorts to the other, “Well you’re ugly!” they have resorted to a fallacious ad hominem argument. You probably aren’t surprised to know that politicians frequently rely on personal attacks, especially when they are sponsored by political action committees (PACs). The proliferation of these organizations resulted in an increase in “attack ads” during the 2012 presidential race. While all fallacious arguments detract from the quality of public communication, ad hominem arguments in particular diminish the civility of our society.

Slippery Slope

The slippery slope fallacy occurs when a person argues that one action will inevitably lead to a series of other actions. If we take one step down an icy hill it becomes difficult to get back up and you slide all the way down even though you only wanted to take one step. A slippery slope fallacy in a speech about US foreign policy might take the form of the following argument: If the United States goes to help this country in need, then we will be expected to intervene any time there’s a conflict in the world.

Red Herring

The red herring fallacy is my favorite because it has an interesting origin—and it was used in Scooby Doo ! The origin of the name of this fallacy comes from old foxhunting practices in England. When the hunters were training their dogs to stay on the trail of a fox, they would mark a trail with fox scent so the dog could practice following the scent. As a further test, they would take the smell of fish (like a red herring) and create a second trail leading in another direction. If a dog left the scent of the fox trail to follow the stronger and more noticeable scent trail left by the red herring, then the dog failed the test. The smartest and best-trained dogs weren’t distracted by the fishy trail and stayed on the path. Basically every episode of Scooby Doo involves a red herring trick—for example, when the ghost at the amusement park turns out to be a distraction created by the owner to cover up his financial problems and shady business practices. A speaker who uses the red herring fallacy makes an argument that distracts from the discussion at hand. Bringing up socialism during an argument about nationalized health care is an example of a red herring fallacy.

Appeal to Tradition

The appeal to tradition fallacy argues that something should continue because “it’s the way things have been done before.” Someone may use this type of argument when they feel threatened by a potential change. People who oppose marriage rights for gay and lesbian people often argue that the definition of marriage shouldn’t change because of its traditional meaning of a “union between one man and one woman.” Such appeals often overstate the history and prevalence of the “tradition.” Within the United States, many departures from traditional views of marriage have led to changes that we accept as normal today. Within the past one hundred years we have seen law changes that took away men’s rights to beat their wives and make decisions for them. And it wasn’t until 1993 that every state made marital rape a crime, which changed the millennia-old “tradition” that women were obligated to have sex with their husbandsf (Coontz, 2006). Many people are resistant to or anxious about change, which is understandable, but this doesn’t form the basis of a good argument.

Review of Fallacies

  • Hasty generalization. Inductive reasoning fallacy that occurs when too few examples are cited to warrant a conclusion.
  • False analogy. Inductive reasoning fallacy that occurs when situations or circumstances being compared are not similar enough.
  • False cause. Causal reasoning fallacy that occurs when a speaker argues with insufficient evidence that one thing caused/causes another.
  • False authority. Fallacy that occurs when a person making an argument doesn’t have the knowledge or qualifications to be credible but is perceived as credible because they are respected or admired.
  • Bandwagon. Fallacy that relies on arguing for a course of action or belief because it is commonly done or held.
  • False dilemma. Fallacy that occurs when a speaker presents an audience only two options and argues they must choose one or the other.
  • Ad hominem. Fallacy that occurs when a speaker attacks another person rather than his or her argument.
  • Slippery slope. Fallacy that occurs when a person argues that one action will inevitably lead to a series of other actions.
  • Red herring. Fallacy that occurs when a speaker poses an argument that is meant to distract from the argument at hand.
  • Appeal to tradition. Fallacy that results when a speaker argues that something should continue because “it’s the way things have been done before.”

Key Takeaways

We use reasoning to make sense of the world around us and draw conclusions. Three types of reasoning are inductive, deductive, and causal.

  • Inductive reasoning refers to arguments that persuade by citing examples that build to a conclusion. Examples should be sufficient, typical, and representative to warrant a strong argument. Reasoning by analogy argues that what is true in one set of circumstances will be true in another, and is an example of inductive reasoning.
  • Deductive reasoning refers to arguments that derive specifics from what is already known and includes syllogisms. Premises that lead to the conclusion must be true and relevant for the argument to be valid.
  • Causal reasoning refers to arguments that establish a relationship between a cause and an effect and usually involves a correlation rather than a true causal relationship.
  • Fallacies refer to flaws within the logic or reasoning of an argument. Ten fallacies of reasoning discussed in this chapter are hasty generalization, false analogy, false cause, false authority, false dilemma, ad hominem, slippery slope, red herring, and appeal to tradition.
  • Identify examples of inductive, deductive, and causal reasoning in the sample persuasive speech on education in prisons included in Section 4.3 “Nonverbal Communication Competence” .
  • People often use fallacies in arguments, usually without knowing it. Being able to identify fallacies is an important critical thinking skill. Find a letter to the editor in a paper or online and see if you can identify any of the ten fallacies discussed in this chapter.
  • Of the ten fallacies discussed in the chapter, which do you think is the most unethical and why?

Coontz, S., “Traditional Marriage Has Changed a Lot,” Seattle Post Intelligencer , February 23, 2006, accessed March 6, 2012, http://www.seattlepi.com/default/article/Traditional-marriage-has-changed-a-lot-1196563.php .

Cooper, M. D., and William L. Nothstine, Power Persuasion: Moving an Ancient Art into the Media Age (Greenwood, IN: Educational Video Group, 1996), 27.

Walter, O. M., Speaking to Inform and Persuade (New York: Macmillan, 1966), 58.

Communication in the Real World Copyright © 2016 by University of Minnesota is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

Effectiviology

Logical Fallacies: What They Are and How to Counter Them

A Basic Guide to Logical Fallacies

  • A logical fallacy is a pattern of reasoning that contains a flaw, either in its logical structure or in its premises.

An example of a logical fallacy is the false dilemma , which is a logical fallacy that occurs when a limited number of options are incorrectly presented as being mutually exclusive to one another or as being the only options that exist, in a situation where that isn’t the case. For instance, a false dilemma occurs in a situation where someone says that we must choose between options A or B, without mentioning that option C also exists.

Fallacies, in their various forms, play a significant role in how people think and in how they communicate with each other, so it’s important to understand them. As such, the following article serves as an introductory guide to logical fallacies, which will help you understand what logical fallacies are, what types of them exist, and what you can do in order to counter them successfully.

Examples of logical fallacies

One example of a logical fallacy is the ad hominem fallacy , which is a fallacy that occurs when someone attacks the source of an argument directly, without addressing the argument itself. For instance, if a person brings up a valid criticism of the company that they work in, someone using the ad hominem fallacy might reply by simply telling them that if they don’t like the way things are done, then that’s their problem and they should leave.

Another example of a logical fallacy is the loaded question fallacy , which occurs when someone asks a question in a way that presupposes an unverified assumption that the person being questioned is likely to disagree with. An example of a loaded question is the following:

“Can you get this task done for me, or are you too busy slacking off?”

This question is fallacious, because it has a flawed premise, and specifically because it suggests that if the person being questioned says that they can’t get the task done, then that must be because they’re too busy slacking off.

Finally, another example of a logical fallacy is the argument from incredulity , which occurs when someone concludes that since they can’t believe that a certain concept is true, then it must be false, and vice versa. For instance, this fallacy is demonstrated in the following saying:

“I just can’t believe that these statistics are true, so that means they must be false.”

In this case, the speaker’s reasoning is fallacious, because their premises are flawed, and specifically their assumption that if they can’t believe the statistics that they’re shown are true, then that must mean that the statistics are false.

Formal and informal logical fallacies

There are two main types of logical fallacies:

  • Formal fallacies. A formal logical fallacy occurs when there is a flaw in the logical structure of an argument, which renders the argument invalid and consequently also unsound . For example, a formal fallacy can occur because the conclusion of the argument isn’t based on its premises.
  • Informal fallacies. An informal logical fallacy occurs when there is a flaw in the premises of an argument, which renders the argument  unsound , even though it may still be valid . For example, an informal fallacy can occur because the premises of an argument are false , or because they’re unrelated to the discussion at hand.

Therefore, there are two main differences between formal and informal logical fallacies. First, formal fallacies contain a flaw in their logical structure , while informal fallacies contain a flaw in their premises . Second, formal fallacies are invalid patterns of reasoning (and are consequently also unsound), while informal fallacies are unsound patterns of reasoning, but can still be valid.

For instance, the following is an example of a formal fallacy :

Premise 1: If it’s raining, then the sky will be cloudy. Premise 2: The sky is cloudy. Conclusion:  It’s raining.

Though both the premises in this example are true, the argument is invalid , since there is a flaw in its logical structure.

Specifically, premise 1 tells us that if it’s raining, then the sky will be cloudy, but that doesn’t mean that if the sky is cloudy (which we know it is, based on premise 2), then it’s necessarily raining. That is, it’s possible for the sky to be cloudy, without it raining, which is why we can’t reach the conclusion that is specified in the argument, and which is why this argument is invalid, despite the fact that its premises are true.

On the other hand, the following is an example of an informal fallacy :

Premise 1: The weatherman said that it’s going to rain next week. Premise 2: The weatherman is always right. Conclusion:  It’s going to rain next week.

Here, the logical structure of the argument is valid. Specifically, since premise 1 tells us that the weatherman said that it’s going to rain next week, and premise 2 tells us that the weatherman is always right, then based on what we know (i.e. on these premises), we can logically conclude that it’s going to rain next week.

However, there is a problem with this line of reasoning, since our assumption that the weatherman is always right (premise 2) is false . As such, even though the logical structure of the argument is valid, the use of a flawed premise means that the overall argument is unsound .

Overall, a sound argument is one that has a valid logical structure and true premises. A formal logical fallacy means that the argument is invalid, due to a flaw in its logical structure, which also means that it’s unsound. An informal logical fallacy means that the argument is unsound, due to a flaw in its premises, even though it has a valid logical structure.

Example of a formal logical fallacy

As we saw above, a formal fallacy occurs when there is an issue with the logical structure of an argument, which renders the argument invalid.

An example of a formal logical fallacy is the masked-man fallacy , which is committed when someone assumes that if two or more names or descriptions refer to the same thing, then they can be freely substituted with one another, in a situation where that’s not the case. For example:

Premise 1: The citizens of Metropolis know that Superman saved their city. Premise 2: Clark Kent is Superman. Conclusion: The citizens of Metropolis know that Clark Kent saved their city.

This argument is invalid, because even though Superman is in fact Clark Kent, the citizens of Metropolis don’t necessarily know Superman’s true identity, and therefore don’t necessarily know that Clark Kent saved their city. As such, even though both the premises of the argument are true, there is a flaw in the argument’s logical structure, which renders it invalid.

Example of an informal logical fallacy

As we saw above, an informal fallacy occurs when there is a flaw in the premises of an argument, which renders the argument unsound.

An example of an informal logical fallacy is the  strawman fallacy , which occurs when a person distorts their opponent’s argument, in order to make it easier to attack. For example:

Alex: I think we should increase the education budget. Bob: I disagree, because if we spend the entire budget on education, there won’t be any money left for other essential things.

Here, Bob’s argument is valid from a formal, logical perspective: if we spend the entire budget on education, there won’t be anything left to spend on other things.

However, Bob’s reasoning is nevertheless fallacious, because his argument contains a false, implicit premise, and namely the assumption that when Alex suggests that we should increase the education budget, he means that the entire budget should be allocated to education. As such, Bob’s argument is unsound, because it relies on flawed premises, and counters an irrelevant point that his opponent wasn’t trying to make.

Fallacious techniques that aren’t logical fallacies

The term ‘fallacious’ has two primary meanings:

  • Containing a logical fallacy.
  • Tending to deceive or mislead.

Accordingly, some misleading rhetorical techniques and patterns of reasoning can be described as “fallacious”, even if they don’t contain a logical fallacy.

For example, the Gish gallop is a fallacious debate technique, which involves attempting to overwhelm your opponent by bringing up as many arguments as possible, with no regard for the relevance, validity, or accuracy of those arguments. Though a Gish gallop may have some arguments that contain logical fallacies, it isn’t a single argument by itself, and therefore isn’t considered a logical fallacy. However, because its overall argumentation pattern revolves around the intent to deceive, this technique is said to be fallacious.

In this regard, note that logical fallacies, in general, tend to include a form of reasoning that is not only logically invalid or unsound in some way, but that is also misleading.

However, it’s important to keep in mind that fallacies and other fallacious techniques aren’t always used with the intention of misleading others. Rather, people often use fallacious arguments unintentionally, both when they’re talking to other people, as well as when they conduct their own internal reasoning process, because the fact that such arguments are misleading can lead those who use them to not notice that they’re flawed in the first place.

Logical fallacies are different from factual errors

It’s important to note that logical fallacies are errors in reasoning, rather than simple factual errors.

For example, though the statement “humans are birds” is flawed, that’s because it contains a simple factual error, rather than a logical fallacy. Conversely, the argument “humans have eyes, and birds also have eyes, therefore humans are birds” contains a logical fallacy, since there is a flaw in its logical structure, which renders it invalid.

How to counter logical fallacies

To counter the use of a logical fallacy, you should first identify the flaw in reasoning that it contains, and then point it out and explain why it’s a problem, or provide a strong opposing argument that counters it implicitly.

For example, consider a situation where someone uses the appeal to nature , which is an informal logical fallacy that involving claiming that something is either good because it’s considered ‘natural’, or bad because it’s considered ‘unnatural’.

Once you’ve identified the use of the fallacy, you can counter it by explaining why its premises are flawed. To achieve this, you can provide examples that demonstrate that things that are “natural” can be bad and that things that are “unnatural” can be good, or you can provide examples that demonstrate the issues with trying to define what “natural” and “unnatural” mean in the first place.

The steps in this approach, where you first identify the use of the fallacy and then either explain why it’s a problem or provide strong counterarguments, are generally the main ones to follow regardless of which fallacy is being used. However, there is some variability in terms of how you implement these steps when it comes to different fallacies and different circumstances, and an approach that will work well in one situation may fail in another.

For example, while a certain approach might work well when it comes to resolving a formal fallacy that you’ve used unintentionally in your own reasoning process, the same approach might be ineffective when it comes to countering an informal fallacy that was used intentionally by someone else for rhetorical purposes.

Finally, it’s also important to keep in mind that sometimes, when responding to the use of fallacious reasoning, dismantling the logic behind your opponent’s reasoning and highlighting its flaws might not work. This is because, in practice, human interactions and debates are highly complex, and involve more than just exchanging logically sound arguments with one another.

Accordingly, you should accept the fact that in some cases, the best way to respond to a logical fallacy in practice isn’t necessarily to properly address it from a logical perspective. For example, your best option might be to modify your original argument in order to counter the fallacious reasoning without explicitly addressing the fact that it’s fallacious, or your best option might be to refuse to engage with the fallacious argument entirely.

Account for unintentional use of fallacies

When you counter fallacies that other people use, it’s important to remember that not every use of a logical fallacy is intentional, and to act accordingly, since accounting for this fact can help you formulate a more effective response.

A useful concept to keep in mind in this regard is  Hanlon’s razor , which is a philosophical principle that suggests that when someone does something that leads to a negative outcome, you should avoid assuming that they acted out of an intentional desire to cause harm, as long as there is a different plausible explanation for their behavior. In this context, Hanlon’s razor means that, if you notice that someone is using a logical fallacy, you should avoid assuming that they’re doing so intentionally, as long as it’s reasonable to do so.

In addition, it’s important to remember that you too might be using logical fallacies unintentionally in your thinking and in your communication with others. To identify cases where you are doing this, try to examine your reasoning, and see if you can identify any flaws, either in the way that your arguments are structured, or in the premises that you rely on in order to make those arguments. Then, adjust your reasoning accordingly, in order to fix these flaws.

Make sure arguments are fallacious before countering

Before you counter an argument that you think is fallacious, you should make sure that it is indeed fallacious, to the best of your ability.

There are various ways to do this, including slowing down your own reasoning process so you can properly think through the argument, or asking the person who proposed the argument to clarify their position.

The approach of asking the other person to clarify their position is highly beneficial in general, because it helps demonstrate that you’re truly interested in what the other person has to say. Furthermore, in cases where the argument in question does turn out to be fallacious, this approach can often help expose the issues with it, and can also help the other person internalize these issues, in a way that you won’t always be able to achieve by pointing them out yourself.

Finally, note that a useful tool to remember in this regard is the principle of charity , which is a philosophical principle that denotes that, when interpreting someone’s statement, you should assume that the best possible interpretation of that statement is the one that the speaker meant to convey. In this context, the principle of charity means that you should not attribute falsehoods, logical fallacies, or irrationality to people’s argument, when there is a plausible, rational alternative available.

Remember fallacious arguments can have true conclusions

It’s important to keep in mind that even if an argument is fallacious, it can still have a true conclusion. Assuming that just because an argument is fallacious then its conclusion must necessarily be false is a logical fallacy in itself, which is known as the fallacy fallacy .

For instance, consider the following example of a formal logical fallacy (which we saw earlier, and which is known as affirming the consequent ):

Premise 1: If it’s raining, then the sky will be cloudy. Premise 2: The sky is cloudy. Conclusion: It’s raining.

This argument is logically invalid, since we can’t be sure that its conclusion is true based on the premises that we have (because it’s possible that the sky is cloudy but that it’s not raining at the same time). However, even though the argument itself is flawed, that doesn’t mean that its conclusion is necessarily false. Rather, it’s possible that the conclusion is true and that it is currently raining; we just can’t conclude this based on the premises

The same holds for informal fallacies. For example, consider the following argument:

Alex: It’s amazing how accurate this personality test I took is. Bob: No it isn’t, it’s pure nonsense.

Here, Bob is using an appeal to the stone , which is a logical fallacy that occurs when a person dismisses their opponent’s argument as absurd, without actually addressing it, or without providing sufficient evidence in order to prove its absurdity. However, even though Bob’s argument is fallacious, that doesn’t mean that its conclusion is wrong; it’s possible that the personality test in question is indeed nonsense, we just can’t tell whether that’s the case based on this argument alone.

Overall, the important thing to understand is that an argument can be fallacious and still have a conclusion that is factually correct. To assume otherwise is fallacious, which is why you shouldn’t discount people’s conclusions simply because the argument that they used to reach those conclusions contains a logical fallacy.

The difference between logical fallacies and cognitive biases

While logical fallacies and cognitive biases appear to be similar to each other, they are two different phenomena. Specifically, while logical fallacies are flawed patterns of argumentation , and are therefore a philosophical concept, cognitive biases are systematic errors in cognition , and are therefore a psychological concept.

Cognitive biases often occur at a more basic level of thinking, particularly when they’re rooted in people’s intuition, and they can lead to the use of various logical fallacies.

For example, the appeal to novelty is a logical fallacy that occurs when something is assumed to be either good or better than something else, simply because it’s perceived as being new and novel.

In some cases, people might use this fallacy due to a cognitive bias that causes them to instinctively prefer things that they perceive as newer. However, people can experience this instinctive preference for newer things without it leading to the use of the appeal to novelty, in cases where they recognize this preference and account for it properly. Furthermore, people can use arguments that rely on the appeal to novelty even if they don’t experience this instinctive preference, and even if they don’t truly believe in what they’re saying.

Overall, the main difference between logical fallacies and cognitive biases is that logical fallacies are a philosophical concept, that has to do with argumentation , while cognitive biases are a psychological concept, that has to do with cognition . In some cases, there is an association between cognitive biases and certain logical fallacies, but there are many situations where one appears entirely without the other.

Summary and conclusions

  • To counter the use of a logical fallacy, you should first identify the flaw in reasoning that it involves, and then point it out and explain why it’s a problem, or provide a strong opposing argument that counters it implicitly.
  • Note that there is some variability in terms of how you should counter different fallacies under different circumstances, and an approach that will work well in one situation may fail in another.
  • When responding to the use of a logical fallacy, it’s important to make sure that it’s indeed a fallacy, to remember that the use of the fallacy might be intentional, and to keep in mind that just because an argument is fallacious doesn’t mean that its conclusion is necessarily wrong.
  • Certain rhetorical techniques and patterns of reasoning can be described as “fallacious” even if they don’t contain a logical fallacy, because they’re used with the intent to deceive or mislead listeners.

Other articles you may find interesting:

  • False Premise: When Arguments Are Built on Bad Foundations
  • False Dilemmas and False Dichotomies: What They Are and How to Respond to Them
  • The Fallacy Fallacy: Why Fallacious Arguments Can Have True Conclusions

SEP home page

  • Table of Contents
  • Random Entry
  • Chronological
  • Editorial Information
  • About the SEP
  • Editorial Board
  • How to Cite the SEP
  • Special Characters
  • Advanced Tools
  • Support the SEP
  • PDFs for SEP Friends
  • Make a Donation
  • SEPIA for Libraries
  • Entry Contents

Bibliography

Academic tools.

  • Friends PDF Preview
  • Author and Citation Info
  • Back to Top

Two competing conceptions of fallacies are that they are false but popular beliefs and that they are deceptively bad arguments. These we may distinguish as the belief and argument conceptions of fallacies. Academic writers who have given the most attention to the subject of fallacies insist on, or at least prefer, the argument conception of fallacies, but the belief conception is prevalent in popular and non-scholarly discourse. As we shall see, there are yet other conceptions of what fallacies are, but the present inquiry focuses on the argument conception of fallacies.

Being able to detect and avoid fallacies has been viewed as a supplement to criteria of good reasoning. The knowledge of fallacies is needed to arm us against the most enticing missteps we might take with arguments—so thought not only Aristotle but also the early nineteenth century logicians Richard Whately and John Stuart Mill. But as the course of logical theory from the late nineteenth-century forward turned more and more to axiomatic systems and formal languages, the study of reasoning and natural language argumentation received much less attention, and hence developments in the study of fallacies almost came to a standstill. Until well past the middle of the twentieth century, discussions of fallacies were for the most part relegated to introductory level textbooks. It was only when philosophers realized the ill fit between formal logic, on the one hand, and natural language reasoning and argumentation, on the other, that the interest in fallacies has returned. Since the 1970s the utility of knowing about fallacies has been acknowledged (Johnson and Blair 1993), and the way in which fallacies are incorporated into theories of argumentation has been taken as a sign of a theory’s level of adequacy (Biro and Siegel 2007, van Eemeren 2010).

In modern fallacy studies it is common to distinguish formal and informal fallacies. Formal fallacies are those readily seen to be instances of identifiable invalid logical forms such as undistributed middle and denying the antecedent. Although many of the informal fallacies are also invalid arguments, it is generally thought to be more profitable, from the points of view of both recognition and understanding, to bring their weaknesses to light through analyses that do not involve appeal to formal languages. For this reason it has become the practice to eschew the symbolic language of formal logic in the analysis of these fallacies; hence the term ‘informal fallacy’ has gained wide currency. In the following essay, which is in four parts, it is what is considered the informal-fallacy literature that will be reviewed. Part 1 is an introduction to the core fallacies as brought to us by the tradition of the textbooks. Part 2 reviews the history of the development of the conceptions of fallacies as it is found from Aristotle to Copi. Part 3 surveys some of the most recent innovative research on fallacies, and Part 4 considers some of the current research topics in fallacy theory.

1. The core fallacies

2.1 aristotle, 2.3 arnauld and nicole, 2.6 bentham, 2.7 whately, 3.1 renewed interest, 3.2 doubts about fallacies, 3.3 the informal logic approach to fallacies, 3.4 the formal approach to informal fallacies, 3.5 the epistemic approach to fallacies, 3.6 dialectical/dialogical approaches to fallacies, 4.1 the nature of fallacies, 4.2 the appearance condition, 4.3 teaching, other internet resources, related entries.

Irving Copi’s 1961 Introduction to Logic gives a brief explanation of eighteen informal fallacies. Although there is some variation in competing textbooks, Copi’s selection captured what for many was the traditional central, core fallacies. [ 1 ] In the main, these fallacies spring from two fountainheads: Aristotle’s Sophistical Refutations and John Locke’s An Essay Concerning Human Understanding (1690). By way of introduction, a brief review of the core fallacies, especially as they appear in introductory level textbooks, will be given. Only very general definitions and illustrations of the fallacies can be given. This proviso is necessary first, because, the definitions (or identity conditions) of each of the fallacies is often a matter of contention and so no complete or final definition can be given in an introductory survey; secondly, some researchers wish that only plausible and realistic instances of each fallacy be used for illustration. This also is not possible at this stage. The advantage of the stock examples of fallacies is that they are designed to highlight what the mistake associated with each kind of fallacy is supposed to be. Additional details about some of the fallacies are found in Sections 2 and 3. As an initial working definition of the subject matter, we may take a fallacy to be an argument that seems to be better than it really is.

1. The fallacy of equivocation is an argument which exploits the ambiguity of a term or phrase which has occurred at least twice in an argument, such that on the first occurrence it has one meaning and on the second another meaning. A familiar example is:

The end of life is death. Happiness is the end of life. So, death is happiness.

‘The end of life’ first means ceasing to live, then it means purpose. That the same set of words is used twice conceals the fact that the two distinct meanings undermine the continuity of the reasoning, resulting in a non-sequitur .

2. The fallacy of amphiboly is, like the fallacy of equivocation, a fallacy of ambiguity; but here the ambiguity is due to indeterminate syntactic structure. In the argument:

The police were told to stop drinking on campus after midnight. So, now they are able to respond to emergencies much better than before

there are several interpretations that can be given to the premise because it is grammatically ambiguous. On one reading it can be taken to mean that it is the police who have been drinking and are now to stop it; this makes for a plausible argument. On another reading what is meant is that the police were told to stop others (e.g., students) from drinking after midnight. If that is the sense in which the premise is intended, then the argument can be said to be a fallacy because despite initial appearances, it affords no support for the conclusion.

3 & 4. The fallacies of composition and division occur when the properties of parts and composites are mistakenly thought to be transferable from one to the other. Consider the two sentences:

  • Every member of the investigative team was an excellent researcher.
  • It was an excellent investigative team.

Here it is ‘excellence’ that is the property in question. The fallacy of composition is the inference from (a) to (b) but it need not hold if members of the team cannot work cooperatively with each other. The reverse inference from (b) to (a)—the fallacy of division—may also fail if some essential members of the team have a supportive or administrative role rather than a research role.

5. The fallacy of begging the question ( petitio principii ) can occur in a number of ways. One of them is nicely illustrated with Whately’s (1875 III §13) example: “to allow everyman an unbounded freedom of speech must always be, on the whole, advantageous to the State; for it is highly conducive to the interest of the Community, that each individual should enjoy a liberty perfectly unlimited, of expressing his sentiments.” This argument begs the question because the premise and conclusion are the very same proposition, albeit expressed in different words. It is a disguised instance of repetition which gives no reason for its apparent conclusion.

Another version of begging the question can occur in contexts of argumentation where there are unsettled questions about key terms. Suppose, for example, that everyone agrees that to murder someone requires doing something that is wrong, but not everyone agrees that capital punishment is a form of ‘murder’; some think it is justified killing. Then, should an arguer gives this argument:

Capital punishment requires an act of murdering human beings. So, capital punishment is wrong.

one could say that this is question-begging because in this context of argumentation, the arguer is smuggling in as settled a question that remains open. That is, if the premise is accepted without further justification, the arguer is assuming the answer to a controversial question without argument.

Neither of these versions of begging the question are faulted for their invalidity, so they are not charged with being non-sequitors like most of the core fallacies; they are, however, attempted proofs that do not transparently display their weakness. This consideration, plus its ancient lineage back to Aristotle, might explain begging the question’s persistent inclusion among fallacies. But, given our allegiance to the modern conception of logic as being solely concerned with the following-from relation, forms of begging the question should be thought of as epistemic rather than logical fallacies.

Some versions of begging the question are more involved and are called circular reasoning. They include more than one inference. Descartes illustrated this kind of fallacy with the example of our belief in the Bible being justified because it is the word of God, and our belief in God’s existence being justified because it is written in the Bible. [ 2 ] The two propositions lead back and forth to each other, in a circle, each having only the support of the other.

6. The fallacy known as complex question or many questions is usually explained as a fallacy associated with questioning. For example, in a context where a Yes or No answer must be given, the question, “Are you still a member of the Ku Klux Klan?” is a fallacy because either response implies that one has in the past been a member of the Klan, a proposition that may not have been established as true. Some say that this kind of mistake is not really a fallacy because to ask a question is not to make an argument.

7. There are a number of fallacies associated with causation, the most frequently discussed is post hoc ergo propter hoc , (after this, therefore because of this). This fallacy ascribes a causal relationship between two states or events on the basis of temporal succession. For example,

Unemployment decreased in the fourth quarter because the government eliminated the gasoline tax in the second quarter.

The decrease in unemployment that took place after the elimination of the tax may have been due to other causes; perhaps new industrial machinery or increased international demand for products. Other fallacies involve confusing the cause and the effect, and overlooking the possibility that two events are not directly related to each other but are both the effect of a third factor, a common cause. These fallacies are perhaps better understood as faults of explanation than faults of arguments.

8. The fallacy of ignoratio elenchi , or irrelevant conclusion, is indicative of misdirection in argumentation rather than a weak inference. The claim that Calgary is the fastest growing city in Canada, for example, is not defeated by a sound argument showing that it is not the biggest city in Canada. A variation of ignoratio elenchi , known under the name of the straw man fallacy, occurs when an opponent’s point of view is distorted in order to make it easier to refute. For example, in opposition to a proponent’s view that (a) industrialization is the cause of global warming, an opponent might substitute the proposition that (b) all ills that beset mankind are due to industrialization and then, having easily shown that (b) is false, leave the impression that (a), too, is false. Two things went wrong: the proponent does not hold (b), and even if she did, the falsity of (b) does not imply the falsity of (a).

There are a number of common fallacies that begin with the Latin prefix ‘ ad ’ (‘to’ or ‘toward’) and the most common of these will be described next.

9. The ad verecundiam fallacy concerns appeals to authority or expertise. Fundamentally, the fallacy involves accepting as evidence for a proposition the pronouncement of someone who is taken to be an authority but is not really an authority. This can happen when non-experts parade as experts in fields in which they have no special competence—when, for example, celebrities endorse commercial products or social movements. Similarly, when there is controversy, and authorities are divided, it is an error to base one’s view on the authority of just some of them. (See also 2.4 below.)

10. The fallacy ad populum is similar to the ad verecundiam , the difference being that the source appealed to is popular opinion, or common knowledge, rather than a specified authority. So, for example:

These days everyone (except you) has a car and knows how to drive; So, you too should have a car and know how to drive.

Often in arguments like this the premises aren’t true, but even if they are generally true they may provide only scant support for their conclusions because that something is widely practised or believed is not compelling evidence that it is true or that it should be done. There are few subjects on which the general public can be said to hold authoritative opinions. Another version of the ad populum fallacy is known as “playing to the gallery” in which a speaker seeks acceptance for his view by arousing relevant prejudices and emotions in his audience in lieu of presenting it with good evidence.

11. The ad baculum fallacy is one of the most controversial because it is hard to see that it is a fallacy or even that it involves bad reasoning. Ad baculum means “appeal to the stick” and is generally taken to involve a threat of injury of harm to the person addressed. So, for example,

If you don’t join our demonstration against the expansion of the park, we will evict you from your apartment; So, you should join our demonstration against the expansion of the park.

Such threats do give us reasons to act and, unpleasant as the interlocutor may be, there seems to be no fallacy here. In labour disputes, and perhaps in international relations, using threats such as going on strike, or cutting off trade routes, are not normally considered fallacies, even though they do involve intimidation and the threat of harm. However, if we change to doxastic considerations, then the argument that you should believe that candidate \(X\) is the one best suited for public office because if you do not believe this you will be evicted from your apartment, certainly is a good instance of irrelevant evidence.

12. The fallacy ad misericordiam is a companion to the ad baculum fallacy: it occurs not when threats are out of place but when appeals for sympathy or pity are mistakenly thought to be evidence. To what extent our sympathy for others should influence our actions depends on many factors, including circumstances and our ethical views. However, sympathy alone is generally not evidence for believing any proposition. Hence,

You should believe that he is not guilty of embezzling those paintings; think of how much his family suffered during the Depression.

Ad misericordiam arguments, like ad baculum arguments, have their natural home in practical reasoning; it is when they are used in theoretical (doxastic) argumentation that the possibility of fallacy is more likely.

13. The ad hominem fallacy involves bringing negative aspects of an arguer, or their situation, to bear on the view they are advancing. There are three commonly recognized versions of the fallacy. The abusive ad hominem fallacy involves saying that someone’s view should not be accepted because they have some unfavorable property.

Thompson’s proposal for the wetlands may safely be rejected because last year she was arrested for hunting without a license.

The hunter Thompson, although she broke the law, may nevertheless have a very good plan for the wetlands.

Another, more subtle version of the fallacy is the circumstantial ad hominem in which, given the circumstances in which the arguer finds him or herself, it is alleged that their position is supported by self-interest rather than by good evidence. Hence, the scientific studies produced by industrialists to show that the levels of pollution at their factories are within the law may be undeservedly rejected because they are thought to be self-serving. Yet it is possible that the studies are sound: just because what someone says is in their self-interest, does not mean it should be rejected.

The third version of the ad hominem fallacy is the tu quoque . It involves not accepting a view or a recommendation because the espouser him- or herself does not follow it. Thus, if our neighbor advises us to exercise regularly and we reject her advice on the basis that she does not exercise regularly, we commit the tu quoque fallacy: the value of advice is not wholly dependent on the integrity of the advisor.

We may finish our survey of the core fallacies by considering just two more.

14. The fallacy of faulty analogy occurs when analogies are used as arguments or explanations and the similarities between the two things compared are too remote to support the conclusion.

If a child gets a new toy he or she will want to play with it; So, if a nation gets new weapons, it will want to use them.

In this example (due to Churchill 1986, 349) there is a great difference between using (playing with) toys and using (discharging) weapons. The former is done for amusement, the latter is done to inflict harm on others. Playing with toys is a benign activity that requires little justification; using weapons against others nations is something that is usually only done after extensive deliberation and as a last resort. Hence, there is too much of a difference between using toys and using weapons to conclude that a nation, if it acquires weapons, will want to use them as readily as children will want to play with their toys.

15. The fallacy of the slippery slope generally takes the form that from a given starting point one can by a series of incremental inferences arrive at an undesirable conclusion, and because of this unwanted result, the initial starting point should be rejected. The kinds of inferences involved in the step-by-step argument can be causal, as in:

You have decided not to go to college; If you don’t go to college, you won’t get a degree; If you don’t get a degree, you won’t get a good job; If you don’t get a good job, you won’t be able to enjoy life; But you should be able to enjoy life; So, you should go to college.

The weakness in this argument, the reason why it is a fallacy, lies in the second and third causal claims. The series of small steps that lead from an acceptable starting point to an unacceptable conclusion may also depend on vague terms rather than causal relations. Lack of clear boundaries is what enables the puzzling slippery slope arguments known as “the beard” and “the heap.” In the former, a person with a full beard eventually becomes beardless as hairs of the beard are removed one-by-one; but because the term ‘beard’ is vague it is unclear at which intermediate point we are to say that the man is now beardless. Hence, at each step in the argument until the final hair-plucking, we should continue to conclude that the man is bearded. In the second case, because ‘heap’ is vague, it is unclear at what point piling scattered stones together makes them a heap of stones: if it is not a heap to begin with, adding one more stone will not make it a heap, etc. In both these cases apparently good reasoning leads to a false conclusion.

Many other fallacies have been named and discussed, some of them quite different from the ones mentioned above, others interesting and novel variations of the above. Some of these will be mentioned in the review of historical and contemporary sources that follows.

2. History of Fallacy Theory

The history of the study of fallacies begins with Aristotle’s work, On Sophistical Refutations . It is among his earlier writings and the work appears to be a continuation of the Topics , his treatise on dialectical argumentation. Although his most extensive and theoretically detailed discussion of fallacies is in the Sophistical Refutations , Aristotle also discusses fallacies in the Prior Analytics and On Rhetoric . Here we will concentrate on summarizing the account given in the Sophistical Refutations . In that work, four things are worth noting: (a) the different conceptions of fallacy; (b) the basic concepts used to explain fallacies; (c) Aristotle’s explanation of why fallacies can be deceptive; and (d) his enumeration and classification of fallacies.

2.1.1 Definitions

At the beginning of Topics (I, i), Aristotle distinguishes several kinds of deductions (syllogisms). They are distinguished first on the basis of the status of their premises. (1) Those that begin from true and primary premises, or are owed to such, are demonstrations. (2) Those which have dialectical premises—propositions acceptable to most people, or to the wise—are dialectical deductions. (3) Deductions that start from premises which only appear to be dialectical, are fallacious deductions because of their starting points, as are (4) those “deductions” that do have dialectical premises but do not really necessitate their conclusions. Other fallacies mentioned and associated with demonstrations are (5) those which only appear to start from what is true and primary ( Top ., I, i 101a5). What this classification leaves out are (6) the arguments that do start from true and primary premises but then fail to necessitate their conclusions; two of these, begging the question and non-cause are discussed in Prior Analytics (II, 16, 17). It is the “fallacious deductions” characterized in (4), however, that come closest to the focus of the Sophistical Refutations . Nevertheless, in many of the examples given what stands out is that the premises are given as answers in dialogue and are to be maintained by the answerer, not necessarily that they are dialectical in the sense of being common opinions. This variation on dialectical deductions Aristotle calls examination arguments ( SR 2 165b4).

2.1.2 The basic concepts

There are three closely related concepts needed to understand sophistical refutations. By a deduction (a syllogism [ 3 ] ) Aristotle meant an argument which satisfies three conditions: it “is based on certain statements made in such a way as necessarily to cause the assertion of things other than those statements and as a result of those statements” ( SR 1 165a1–2). Thus an argument may fail to be a syllogism in three different ways. The premises may fail to necessitate the conclusion, the conclusion may be the same as one of the premises, and the conclusion may not be caused by (grounded in) the premises. The concept of a proof underlying Sophistical Refutations is similar to what is demanded of demonstrative knowledge in Posterior Analytics (I ii 71b20), viz., that the premises must be “true, primary, immediate, better known than, prior to, and causative of the conclusion,” except that the first three conditions do not apply to deductions in which the premises are obtained through questioning. A refutation , Aristotle says, is “a proof of the contradictory” ( SR 6, 168a37)—a proof of the proposition which is the contradictory of the thesis maintained by the answerer. In a context of someone, S , maintaining a thesis, T , a dialectical refutation will consist in asking questions of S , and then taking S ’s answers and using them as the premises of a proof via a deduction of not-T : this will be a refutation of T relative to the answerer ( SR 8 170a13). The concept of contradiction can be found in Categories : it is those contraries which are related such that “one opposite needs must be true, while the other must always be false” (13b2–3). A refutation will be sophistical if either the proof is only an apparent proof or the contradiction is only an apparent contradiction. Either way, according to Aristotle, there is a fallacy. Hence, the opening of his treatise: “Let us now treat of sophistical refutations, that is, arguments which appear to be refutations but are really fallacies and not refutations” ( SR 1 164a20).

2.1.3 The appearance condition

Aristotle observed that “reasoning and refutation are sometimes real and sometimes not, but appear to be real owing to men’s inexperience; for the inexperienced are like those who view things from a distance” ( SR , 1 164b25). The ideas here are first that there are arguments that appear to be better than they really are; and second that people inexperienced in arguments may mistake the appearance for the reality and thus be taken in by a bad argument or refutation. Apparent refutations are primarily explained in terms of apparent deductions: thus, with one exception, Aristotle’s fallacies are in the main a catalogue of bad deductions that appear to be good deductions. The exception is ignoratio elenchi in which, in one of its guises, the deduction contains no fallacy but the conclusion proved only appears to contradict the answerer’s thesis.

Aristotle devotes considerable space to explaining how the appearance condition may arise. At the outset he mentions the argument that turns upon names ( SR 1 165a6), saying that it is the most prolific and usual explanation: because there are more things than names, some names will have to denote more than one thing, thereby creating the possibility of ambiguous terms and expressions. That the ambiguous use of a term goes unnoticed allows the illusion that an argument is a real deduction. The explanation of how the false appearance can arise is in the similarity of words or expressions with different meanings, and the smallness of differences in meaning between some expressions ( SR 7 169a23–169b17).

2.1.4 List and classification

Aristotle discusses thirteen ways in which refutations can be sophistical and divides them into two groups. The first group, introduced in Chapter 4 of On Sophistical Refutations , includes those Aristotle considers dependent on language ( in dictione ), and the second group, introduced in Chapter 5, includes those characterized as not being dependent on language ( extra dictionem ). Chapter 6 reviews all the fallacies from the view point of failed refutations, and Chapter 7 explains how the appearance of correctness is made possible for each fallacy. Chapters 19–30 advise answerers on how to avoid being taken in by sophistical refutations.

The fallacies dependent on language are equivocation, amphiboly, combination of words, division of words, accent and form of expression. Of these the first two have survived pretty much as Aristotle thought of them. Equivocation results from the exploitation of a term’s ambiguity and amphiboly comes about through indefinite grammatical structure. The one has to do with semantical ambiguity, the other with syntactical ambiguity. However, the way that Aristotle thought of the combination and division fallacies differs significantly from modern treatments of composition and division. Aristotle’s fallacies are the combinations and divisions of words which alter meanings, e.g., “walk while sitting” vs. “walk-while-sitting,” (i.e., to have the ability to walk while seated vs. being able to walk and sit at the same time). For division, Aristotle gives the example of the number 5: it is 2 and 3. But 2 is even and 3 is odd, so 5 is even and odd. Double meaning is also possible with those words whose meanings depend on how they are pronounced, this is the fallacy of accent, but there were no accents in written Greek in Aristotle’s day; accordingly, this fallacy would be more likely in written work. What Aristotle had in mind is something similar to the double meanings that can be given to ‘unionized’ and ‘invalid’ depending on how they are pronounced. Finally, the fallacy that Aristotle calls form of expression exploits the kind of ambiguity made possible by what we have come to call category mistakes, in this case, fitting words to the wrong categories. Aristotle’s example is the word ‘flourishing’ which may appear to be a verb because of its ‘ing’ ending (as in ‘cutting’ or ‘running’) and so belongs to the category of actions, whereas it really belongs in the category of quality. Category confusion was, for Aristotle, the key cause of metaphysical mistakes.

There are seven kinds of sophistical refutation that can occur in the category of refutations not dependent on language: accident, secundum quid , consequent, non-cause, begging the question, ignoratio elenchi and many questions.

The fallacy of accident is the most elusive of the fallacies on Aristotle’s list. It turns on his distinction between two kinds of predication, unique properties and accidents ( Top . I 5). The fallacy is defined as occurring when “it is claimed that some attribute belongs similarly to the thing and to its accident” ( SR 5 166b28). What belongs to a thing are its unique properties which are counterpredicable (Smith 1997, 60), i.e., if \(A\) is an attribute of \(B\), \(B\) is an attribute of \(A\). However, attributes that are accidents are not counterpredicates and to treat them as such is false reasoning, and can lead to paradoxical results; for example, if it is a property of triangles that they are equal to two right angles, and a triangle is accidentally a first principle, it does not follow that all first principles have two right angles (see Schreiber 2001, ch. 7).

Aristotle considers the fallacy of consequent to be a special case of the fallacy of accident, observing that consequence is not convertible, i.e., “if \(A\) is, \(B\) necessarily is, men also fancy that, if \(B\) is, \(A\) necessarily is” ( SR 5 169b3). One of Aristotle’s examples is that it does not follow that “a man who is hot must be in a fever because a man who is in a fever is hot” ( SR 5 169b19). This fallacy is sometimes claimed as being an early statement of the formal fallacy of affirming the consequent.

The fallacy of secundum quid comes about from failing to appreciate the distinction between using words absolutely and using them with qualification. Spruce trees, for example, are green with respect to their foliage (they are ‘green’ with qualification); it would be a mistake to infer that they are green absolutely because they have brown trunks and branches. It is because the difference between using words absolutely and with qualification can be minute that this fallacy is possible, thinks Aristotle.

Begging the question is explained as asking for the answer (the proposition) which one is supposed to prove, in order to avoid having to make a proof of it. Some subtlety is needed to bring about this fallacy such as a clever use of synonymy or an intermixing of particular and universal propositions ( Top . VIII, 13). If the fallacy succeeds the result is that there will be no deduction: begging the question and non-cause are directly prohibited by the second and third conditions respectively of being a deduction ( SR 6 168b23).

The fallacy of non-cause occurs in contexts of ad impossibile arguments when one of the assumed premises is superfluous for deducing the conclusion. The superfluous premise will then not be a factor in deducing the conclusion and it will be a mistake to infer that it is false since it is a non-cause of the impossibility. This is not the same fallacy mentioned by Aristotle in the Rhetoric (II 24) which is more akin to a fallacy of empirical causation and is better called false cause (see Woods and Hansen 2001).

Aristotle’s fallacy of many questions occurs when two questions are asked as if they are one proposition. A proposition is “a single predication about a single subject” ( SR 6 169a8). Thus with a single answer to two questions one has two premises for a refutation , and one of them may turn out to be idle, thus invalidating the deduction (it becomes a non-cause fallacy). Also possible is that extra-linguistic part-whole mistakes may happen when, for example, given that something is partly good and partly not-good, the double question is asked whether it is all good or all not-good? Either answer will lead to a contradiction (see Schreiber 2000, 156–59). Despite its name, this fallacy consists in the ensuing deduction, not in the question which merely triggers the fallacy.

On one interpretation ignoratio elenchi is considered to be Aristotle’s thirteenth fallacy, in which an otherwise successful deduction fails to end with the required contradictory of the answerer’s thesis. Seen this way, ignoratio elenchi is unlike all the other fallacies in that it is not an argument that fails to meet one of the criteria of a good deduction, but a genuine deduction that turns out to be irrelevant to the point at issue. On another reading, ignoratio elenchi is not a separate fallacy but an alternative to the language dependent / language independent way of classifying the other twelve fallacies: they all fail to meet, in one way or another, the requirements of a sound refutation.

[A] refutation is a contradiction of one and the same predicate, not of a name but of a thing, and not of a synonymous name but of an identical name, based on the given premises and following necessarily from them (the original point at issue not being included) in the same respect, manner and time. ( SR 5 167a23–27)

Each of the other twelve fallacies is analysed as failing to meet one of the conditions in this definition of refutation ( SR 6). Aristotle seems to favour this second reading, but it leaves the problem of explaining how refutations that miss their mark can seem like successful refutations. A possible explanation is that a failure to contradict a given thesis can be made explicit by adding the negation of the thesis as a last step of the deduction, thereby insuring the contradiction of the thesis, but only at the cost (by the last step) of introducing one of the other twelve fallacies in the deduction.

2.1.5 Different interpretations

I have given only the briefest possible explanation of Aristotle’s fallacies. To really understand them a much longer engagement with the original text and the secondary sources is necessary. The second chapter of Hamblin’s (1970) book is a useful introduction to the Sophistical Refutations , and a defence of the dialectical nature of the fallacies. Hamblin thinks that a dialectical framework is indispensable for an understanding of Aristotle’s fallacies and that part of the poverty of contemporary accounts of fallacies is due to a failure to understand their assumed dialectical setting. This approach to the fallacies is continued in contemporary research by some argumentation theorists, most notably Douglas Walton (1995) who also follows Aristotle in recognizing a number of different kinds of dialogues in which argumentation can occur; Frans van Eemeren and Rob Grootendorst (2004) who combine dialectical and pragmatic insights with an ideal model of a critical discussion; and Jaakko Hintikka who analyses the Aristotelian fallacies as mistakes in question-dialogues (Hintikka 1987; Bachman 1995.) According to Hintikka (1997) it is an outright mistake to think of Aristotle’s fallacies primarily as mistaken inferences, either deductive or inductive. A non-dialogue oriented interpretation of Aristotle fallacies is found in Woods and Hansen (1997 and 2001) who argue that the fallacies (apparent deductions) are basic to apparent refutations, and that Aristotle’s interest in the fallacies extended beyond dialectical contests, as is shown by his interest in them in the Prior Analytics and the Rhetoric (II 24). What gives unity to Aristotle’s different fallacies on this view is not a dialogue structure but rather their dependence on the concepts of deduction and proof. The most thorough recent study of these questions is in Schreiber (2003), who emphasizes Aristotle’s concern with resolving (exposing) fallacies and argues that it is Aristotelian epistemology and metaphysics that is needed for a full understanding of the fallacies in the Sophistical Refutations .

Francis Bacon deserves a brief mention in the history of fallacy theory, not because he made any direct contribution to our knowledge of the fallacies but because of his attention to prejudice and bias in scientific investigation, and the effect they could have on our beliefs. He spoke of false idols (1620, aphorisms 40–44) as having the same relation to the interpretation of nature that fallacies have to logic. The idol of the tribe is human nature which distorts our view of the natural world (it is a false mirror). The idol of the cave is the peculiarity of each individual man, our different abilities and education that affect how we interpret nature. The idols of the theatre are the acquired false philosophies, systems and methods, both new and ancient, that rule men’s minds. These three idols all fall into the category of explanations of why we may misperceive the world. A fourth of Bacon’s idols, the idol of the market place, is the one that comes closest to the Aristotelian tradition as it points to language as the source of our mistaken ideas: “words plainly force and overrule the understanding, and throw all into confusion, and lead men away into numberless empty controversies and idle fancies” (1620, aphorism 43). Although Bacon identifies no particular fallacies in Aristotle’s sense, he opens the door to the possibility that there may be false assumptions associated with the investigation of the natural world. The view of The New Organon is that just as logic is the cure for fallacies, so will the true method of induction be a cure for the false idols.

Antoine Arnauld and Pierre Nicole were the authors of Logic, or the Art of Thinking (1662), commonly known as the Port-Royal Logic. According to Benson Mates (1965, 214) it “is an outstanding early example of the ‘how to think straight’ genre.” The work includes chapters on sophisms, with the justification that “examples of mistakes to be avoided are often more striking than the examples to be imitated” (Bk. III, xix). The Port-Royal Logic does not continue Aristotle’s distinction between fallacies that are dependent on language and those that are not; instead there is a division between sophisms associated with scientific subjects (ibid.)—these are nearly all from the Sophistical Refutations —and those committed in everyday life and ordinary discourse (Bk III, xx). The division is not exclusive, with some of the sophisms fitting both classes.

The Port-Royal Logic includes eight of Aristotle’s original thirteen fallacies, several of them modified to fit the bent to natural philosophy rather than dialectical argumentation. Several kinds of causal errors are considered under the broad heading, non causa pro causa and they are illustrated with reference to scientific explanations that have assigned false causes for empirical phenomena. Also identified as a common fallacy of the human mind is post hoc, ergo propter hoc : “This happened following a certain thing, hence that thing must be its cause” (Bk. III, xix 3). Begging the questions is included and illustrated, interestingly, with examples drawn from Aristotelian science. Two new sophisms are included: one is imperfect enumeration, the error of overlooking an alternative, the other is a faulty (incomplete) induction, what we might call hasty generalization. Although the discussions here are brief, they mark the entry of inductive fallacies into the pool of present day recognized fallacies. Ignoratio elenchi retains its dialogical setting but is extended beyond the mere failure to contradict a thesis, “to attribut[ing] to our adversaries something remote from their views to gain an advantage over them, or to impute to them consequences we imagine can be drawn from their doctrines, although they disavow and deny them” (Bk. III, xix 1). The other Aristotelian fallacies included are accident, combination and division, secundum quid and ambiguity.

The sophisms of everyday life and ordinary discourse are eight in number and two of them, the sophisms of authority and manner, should be noticed. In these sophisms, external marks of speakers contribute to the persuasiveness of their arguments. Although authority is not to be doubted in church doctrines, in matters that God has left to the discernment of humans we can be led away from the truth by being too deferential. Here we find one of the earliest statements of the modern appeal to false authority: people are often persuaded by certain qualities that are irrelevant to the truth of the issue being discussed. Thus there are a number of people who unquestioningly believe those who are the oldest and most experienced, even in matters that depend neither on age nor experience, but only on mental insight (Bk. III, xx 6). To age and experience Arnauld and Nicole add noble birth as an unwarranted source of deference in matters intellectual (Bk. III, xx 7), and towards the end of their discussion they add the sophism of manner, cautioning that “grace, fluency, seriousness, moderation and gentleness” is not necessarily a mark of truth (Bk. III, xx 8). The authors seem to have the rhetorical flourishes of royal courtiers especially in mind.

It is John Locke who is credited with intentionally creating a class of ad -arguments, and inadvertently giving birth to the class of ad -fallacies. In An Essay Concerning Human Understanding (1690), he identified three kinds of arguments, the ad verecundiam , ad ignorantiam , and ad hominem arguments, each of which he contrasted with ad judicium arguments which are arguments based on “the foundations of knowledge and probability” and are reliable routes to truth and knowledge. Locke did not speak of ad -arguments as fallacies—that was left to others to do later—but rather as kinds of arguments “that men, in their reasoning with others, do ordinarily make use of to prevail on their assent; or at least so to awe them as to silence their opposition.” (Bk IV, xvii, 19–22).

Two of the ad arguments have developed beyond how Locke originally conceived them. His characterization of the ad verecundiam is considered the locus classicus of appeal-to-authority arguments. When it is a fallacy it is either on the ground that authorities (experts) are fallible or for the reason that appealing to authority is an abandonment of an individual’s epistemic responsibility. It seems unlikely, however, that Locke thought we should never rely on the expertise and superior knowledge of others when engaged in knowledge-gathering and argumentation. This leads us to consider what kind of authority Locke might have had in mind. In addition to epistemic and legal (command) authority there is also what might be called social authority, demanding respect and deference from others due to one’s higher social standing, something much more a part of seventeenth-century society than it is a part of ours. The language that Locke used in connection with the ad verecundiam , words like ‘eminency’, ‘dignity’, ‘breach of modesty’, and ‘having too much pride’ suggests that what he had in mind was the kind of authority that demands respect for the social standing of sources rather than for their expertise; hence, by this kind of authority a person could be led to accept a conclusion because of their modesty or shame, more so than for the value of the argument (see Goodwin 1998, Hansen 2006). Hence, we understand Locke better when we translate ad verecundiam literally, as “appeal to modesty.”

The argumentum ad hominem , as Locke defined it, has subsequently developed into three different fallacies. His original description was that it was a way “to press a man with consequences drawn from his own principles or concessions.” That is, to argue that an opponent’s view is inconsistent, logically or pragmatically, with other things he has said or to which he is committed. Locke’s observation was that such arguments do not advance us towards truth, but that they can serve to promote agreement or stall disagreement. To argue that way is not a fallacy but an acceptable mode of argumentation. Henry Johnstone (1952) thought it captured the essential character of philosophical argumentation. The modern descendants of the Lockean ad hominem are the abusive ad hominem which is an argument to the effect that a position should not be accepted because of some telling negative property of its espouser; the circumstantial ad hominem , an argument to the effect that someone’s position should be rejected because circumstances suggest that their view is the result of self-interested bias; and finally, the tu quoque ad hominem argument which attempts to deflect a criticism by pointing out that it applies equally to the accuser. Recent scholarship suggests that these post-Lockean kinds of ad hominem arguments are sometimes used fairly, and sometimes fallaciously; but none of them is what Locke described as the argumentum ad hominem .

Ad ignorantiam translates as “appeal to ignorance.” Locke’s characterization of this kind of argument is that it demands “the adversary to admit what they allege as a proof, or to assign a better.” The ignorance in question is comparative, it is not that the opponent has no evidence, it is that s/he has no better evidence. However, the inability of an opponent to produce a better argument is not sufficient reason to think the proponent’s argument must be accepted. Modern versions of this kind of argument take it as a fallacy to infer a proposition to be true because there is no evidence against it (see Krabbe, 1995).

The introduction and discussion of the ad -arguments appears almost as an afterthought in Locke’s Essay . It is found at the end of the chapter, “Of Reason,” in which Locke devotes considerable effort to criticizing syllogistic logic. Reasoning by syllogisms, he maintained, was neither necessary nor useful for knowledge. Locke clearly thought that the three ad -arguments were inferior to ad judicium arguments, but he never used the term ‘fallacy’ in connection with them, although he did use it in connection with errors of syllogistic reasoning.

Was Locke the first to discuss these kinds of arguments? Hamblin (1970, 161–62) and Nuchelmans (1993) trace the idea of ad hominem arguments back to Aristotle, and Locke’s remark that the name argumentum ad hominem was already known has been investigated by Finocchiaro (1974) who finds the term and the argument kind in Galileo’s writings more than a half-century before the Essay Concerning Human Understanding . And Arnauld and Nicole’s discussion of the sophism of authority, that “people speak the truth because they are of noble birth or wealthy or in high office,” which seems to be part of Locke’s ad verecundiam , was most likely known to him. Subsequently more ad -arguments were added to the four that Locke identified (see Watts, and Copi, below).

Isaac Watts in his Logick; or, The Right Use of Reason (1724), furthered the ad -argument tradition by adding three more arguments: argumentum ad fidem (appeal to faith), argumentum ad passiones (appeal to passion), and argumentum ad populum (a public appeal to passions). Like Locke, Watts does not consider these arguments as fallacies but as kinds of arguments. However, the Logick does consider sophisms and introduces “false cause” as an alternative name for non causa pro causa which here, as in the Port-Royal Logic, is understood as a fallacy associated with empirical causation. According to Watts it occurs whenever anyone assigns “the reasons of natural appearances, without sufficient experiments to prove them” (1796, Pt. III, 3 i 4). Another sophism included by Watts is imperfect enumeration or false induction, the mistake of generalizing on insufficient evidence. Also, the term ‘strawman fallacy’ may have its origins in Watts’s discussion of ignoratio elenchi : after having dressed up the opinions and sentiments of their adversaries as they please to make “images of straw”, disputers “triumph over their adversary as though they had utterly confuted his opinions” (1796, Pt. III 3 i 1).

Jeremy Bentham’s Handbook of Political Fallacies (1824) was written in the years leading up to the first Reform Bill (1832). His interest was in political argumentation, particularly in exposing the different means used by parliamentarians and law makers to defeat or delay reform legislation. Hence, it was not philosophy or science that interested him, but political debate. Fallacies he took to be arguments or topics that would through the use of deception produce erroneous beliefs in people (1824, 3). These tactics he (or his editor) divided into four classes: fallacies of authority, danger, delay and confusion. Bentham was aware of the developing ad -fallacies tradition since each of the thirty or so fallacies he described is also labelled as belonging either to the kind ad verecundiam (appeal to shame or modesty), ad odium (appeal to hate or contempt), ad metum (appeal to fear or threats), ad quietem (appeal to rest or inaction), ad judicium , and ad socordiam (appeal to postponement or delay). Most of Bentham’s fallacies have not become staples of fallacy theory but many of them show interesting insights into the motives and techniques of debaters (see e.g., Rudanko’s (2005, 2009) analyses of the ad socordiam ).

Bentham’s Handbook has not taken a central place in the history of fallacy studies (Hamblin 1970, 165–69); nevertheless, it is historically interesting in several respects. It discusses authority at length, identifying four conditions for reliable appeals to authority and maintaining that the failure of any one of them cancels the strength of the appeal. Fallacies of authority in political debate occur when authority “is employed in the place of such relevant arguments as might have been brought forward” (1824, 25). Bentham’s fear is that debaters will resort to “the authority” of traditional beliefs and principles instead of considering the advantages of the reform measures under discussion.

Under the heading “fallacies of danger” Bentham named a number of what he called vituperative fallacies—imputations of bad character, bad motive, inconsistency, and suspicious connections—which have as their common characteristic, “the endeavour to draw aside attention from the measure to the man , in such a way as to cause the latter’s badness to be imputed to the measure he supports, or his goodness to his opposition” (1824, 83). This characterization fits well with the way we have come to think of the ad hominem fallacy as a view disparaged by putting forth a negative characterization of its supporter or his circumstances.

Bentham places the fallacies in the immediate context of debate, identifying ways in which arguers frustrate the eventual resolution of disagreements by using insinuations of danger, delaying tactics, appeals to questionable authorities and, generally, confusing issues. Modern argumentation theorists who hold that any impediment to the successful completion of dialogical discussions is a fallacy, may find that their most immediate precursor was Bentham (see Grootendorst 1997).

Book III of Richard Whately’s Elements of Logic (1826) is devoted to giving an account of fallacies based on “logical principles,”. Whately was instrumental in the revival of interest in logic at the beginning of the nineteenth century and, being committed to deductivism, he maintained that only valid deductive inferences counted as reasoning. Thus, he took every fallacy to belong to either the class of deductive failures (logical fallacies) or the class of non-logical failures (material fallacies).

By ‘fallacy’ Whately meant “any unsound mode of arguing, which appears to demand our conviction, and to be decisive of the question at hand, when in fairness it is not”’ (Bk. III, intro.). The logical fallacies divide into the purely logical and the semi-logical fallacies. The purely logical fallacies are plain violations of syllogistic rules like undistributed middle and illicit process. The semi-logical fallacies mostly trade on ambiguous middle terms and are therefore also logical fallacies, but their detection requires extra-logical knowledge including that of the senses of terms [ 4 ] and knowledge of the subject matter (Bk. III, §2); they include, among others, the fallacies of ambiguity, and division and composition. The non-logical, material fallacies are also divided into two classes: fallacies with premises ‘unduly assumed,’ and fallacies of irrelevant conclusions. Begging the question fits under the heading of a non-logical, material fallacy in which a premise has been unduly assumed, and ignoratio elenchi is a non-logical, material fallacy in which an irrelevant conclusion has been reached. The ad -arguments are all placed under the last division as variants of ignoratio elenchi , but they are said to be fallacies only when they are used unfairly. Whately’s version of the ad hominem argument resembles Locke’s in that it is an ex concessis kind of argument: one that depends on the concessions of the person with whom one is arguing. From the concessions, one might prove that one’s opponent is ‘committed to p, ’ but an attempt to make it seem as if this constitutes a proof of the absolute (non-relative) proposition ‘ p ’ would be a fallacy. This kind of ad hominem fallacy can be seen as falling under the broader ignoratio elenchi category because what is proved is not what is needed.

The creation of the category of non-logical fallacies was not really a break with Aristotle as much as it was a break with what had become the Aristotelian tradition. Aristotle thought that some fallacies were due to unacceptable premises although these are not elaborated in Sophistical Refutations (see section 2.1.1 above). Whately’s creation of the category of non-logical fallacies solved the problem of what to do with begging the question which is not an invalid form of argument, and it also created a place in fallacy taxonomy for the ad -fallacies.

John Stuart Mill’s contribution to the study of fallacies is found in Book V of his comprehensive A System of Logic, Ratiocinative and Inductive , first published in 1843. It stands out most strikingly for placing the study of fallacies within his framework of inductive reasoning, a direct rejection of Whately’s deductivist approach to reasoning and fallacies. Mill held that only inductive reasoning counts as inferring and accordingly he introduces new categories as well as a new classification scheme for fallacies.

Mill drew a division between the moral and the intellectual causes of fallacies. The former are aspects of human nature such as biases and indifference to truth which incline us to make intellectual mistakes. These dispositions are not themselves fallacies. It is the intellectual errors, the actual taking of insufficient evidence as sufficient, that are fallacious. The various ways in which this can happen are what Mill took as the basis for classifying fallacies. “A catalogue of the varieties of evidence which are not real evidence,” he wrote, “is an enumeration of fallacies” (1891, Bk.V iii §1).

Mill divided the broad category of argument fallacies into two groups: those in which the evidence is distinctly conceived and those in which it is indistinctly conceived. Fallacies falling under evidence indistinctly conceived (Bk. V, vii) were further described as fallacies of confusion. These result from an indistinct conception of the evidence leading to a mistaking of its significance and thereby to an unsupported conclusion. Some of the traditional Aristotelian fallacies such as ambiguity, composition and division, petitio principii , and ignoratio elenchi , are placed in this category. Although Mill followed Whately closely in his exposition of the fallacies of confusion, he does not mention any ad -arguments in connection with ignoratio elenchi .

As for the category of fallacies of evidence distinctly conceived, it too is divided. The two sub-classes are fallacies of ratiocination (deduction) and fallacies of induction. The deductive fallacies (Bk.V, vi) are those that explicitly break a rule of the syllogism, such as the three-term rule. But also included are the conversion of universal affirmatives and particular negatives (“All PS” does not follow from “All SP,” and “Some P not S” does not follow from “Some S not P”). Also included in this category is the secundum quid fallacy.

The other sub-class of fallacies distinctly conceived bring out what is distinctive about Mill’s work on the fallacies: that it is the first extensive attempt to deal with fallacies of induction. He divided inductive fallacies into two further groups: fallacies of observation (V, iv) and fallacies of generalization (Bk. V, v). Fallacies of observation can occur either negatively or positively. Their negative occurrence consists in non-observation in which one has overlooked negatively relevant evidence. This is similar to what the Port-Royal Logic considered a faulty enumeration, and one of Mill’s examples is the continued faith that farmers put in the weather forecasts found in almanacs despite their long history of false predictions. Observation fallacies occur positively when the mistake is based on something that is seen wrongly, i.e., taken to be something that it is not. Such mal-observations occur when we mistake our inferences for facts, as in our inference that the sun rises and sets (Bk. V, iv, 5).

Fallacies of generalization, the other branch of inductive fallacies, result from mistakes in the inductive process which can happen in several ways. As one example, Mill pointed to making generalizations about what lies beyond our experience: we cannot infer that the laws that operate in remote parts of the universe are the same as those in our solar system (Bk. V, v, 2). Another example is mistaking empirical laws stating regularities for causal laws—his example was because women as a class have not hitherto equalled men as a class, they will never be able to do so (Bk. V, v, 4). Also placed in the category of fallacies of generalization is post hoc ergo propter hoc , which tends to single out a single cause when there are in reality many contributing causes (Bk. V, v, 5). Analogical arguments are identified as a false basis for generalizations; they are “at best only admissible as an inconclusive presumption, where real proof is unattainable” (Bk. V, v, 6).

Mill also included what he calls fallacies of inspection, or a priori fallacies (Bk. V, iii) in his survey of fallacies. These consist of non-inferentially held beliefs, so they fit the belief conception of fallacies rather than the argument conception. Among Mill’s examples of a priori fallacies are metaphysical assumptions such as that distinctions of language correspond to distinctions in nature, and that objects cannot affect each other at a distance. Even the belief in souls or ghosts is considered an a priori fallacy. Such beliefs will not withstand scrutiny, thought Mill, by the inductive method strictly applied.

A System of Logic is the most extensive work on fallacies since Aristotle’s Sophistical Refutations . Mill’s examples are taken from a wide range of examples in science, politics, economics, religion and philosophy. His classificatory scheme is original and comprehensive. Frederick Rosen (2006) argues that Mill’s pre-occupation with the detection and prevention of fallacies is part of what motivates the celebrated second chapter of On Liberty . Despite these considerations, the Logic is not much referenced by fallacy theorists.

Irving Copi’s Introduction to Logic —an influential text book from the mid-twentieth century—defines a fallacy as “a form of argument that seems to be correct but which proves, upon examination, not to be so.” (1961, 52) The term ‘correct’ is sufficiently broad to allow for both deductive invalidity, inductive weakness, as well as some other kinds of argument failure. Of the eighteen informal fallacies Copi discusses, eleven can be traced back to the Aristotelian tradition, and the other seven to the burgeoning post-Lockean ad -fallacy tradition.

The first division in Copi’s classification is between formal and informal fallacies. Formal fallacies are invalid inferences which “bear a superficial resemblance” to valid forms of inference, so these we may think of as deductive fallacies. They include affirming the consequent, denying the antecedent, the fallacy of four terms, undistributed middle, and illicit major. Informal fallacies are not characterized as resembling formally valid arguments; they gain their allure some other way. One division of informal fallacies is the fallacies of relevance which are “errors in reasoning into which we may fall because of carelessness and inattention to our subject matter” (1961, 53). This large class of fallacies includes accident, converse accident, false cause, petitio principii , complex question, ignoratio elenchi , ad baculum , ad hominem abusive, ad hominem circumstantial, ad ignorantiam , ad misericordiam , ad populum , and ad verecundiam . The other division of informal fallacies is called fallacies of ambiguity and it includes equivocation, amphiboly, accent, composition and division.

It seems that Copi took Whately’s category of semi-logical fallacies and moved them under a new heading of ‘informal fallacies,’ presumably for the reason that extra-logical knowledge is needed to uncover their invalidity. This has the result that the new wide category of informal fallacies is a mixed bag: some of them are at bottom logical failures (equivocation, composition, ad misericordiam ) and some are logically correct but frustrate proof (begging the question, ignoratio elenchi ). [ 5 ] Copi’s classification, unlike Whately’s which sought to make a distinction on logical grounds, may be seen as based on three ways that fallacies resemble good arguments: formal fallacies have invalid forms that resemble valid forms, fallacies of ambiguity resemble good arguments through the ambiguity of terms, and fallacies of relevance exploit psychological (non-logical) associations. Hence, we may think of Copi’s divisions as between logical, semantic and psychological fallacies.

Copi’s treatment of the fallacies is a fair overview of the traditional list of fallacies, albeit he did not pretend to do any more than give an introduction to existing fallacy-lore for beginning logic students. Hamblin (1970, ch. 1) criticized Copi’s work, along with that of several others, and gave it the pejorative name, “the standard treatment of fallacies.” His criticisms rang true with many of his readers, thereby provoking contempt for the traditional treatment of fallacies as well as stimulating research in what we may call the new, or post-Hamblin, era, of fallacy studies. Let us next consider some of these developments.

3. New approaches to fallacies

A common complaint since Whately’s Elements of Logic is that our theory and teaching of fallacies are in want of improvement—he thought they should be put on a more logical footing to overcome the loose and vague treatments others had proffered.

It is on Logical principles therefore that I propose to discuss the subject of Fallacies. … the generality of Logical writers have usually followed so opposite a plan. Whenever they have to treat of anything that is beyond the mere elements of Logic, they totally lay aside all reference to the principles they have been occupied in establishing and explaining, and have recourse to a loose, vague, and popular kind of language … [which is] … strangely incongruous in a professional Logical treatise. (1875, III, intro.)

Charles Hamblin’s 1970 book, Fallacies , revives Whately’s complaint. We may view Fallacies as the dividing line between traditional approaches to the study of fallacies and new, contemporary approaches. At the time of its publication it was the first book-length work devoted to fallacies in modern times. The work opens with a critique of the standard treatment of fallacies as it was found in mid-twentieth century textbooks; then, in subsequent chapters, it takes a historical turn reviewing Aristotle’s approach to fallacies and exploring the tradition it fostered (as in the previous section of this entry). Other historically-oriented chapters include one on the Indian tradition, and one on formal fallacies. Hamblin’s more positive contributions to fallacy studies are concentrated in the book’s later chapters on the concept of argument, formal dialectics, and equivocation.

What Hamblin meant by “the standard treatment of fallacies” was:

The typical or average account as it appears in the typical short chapter or appendix of the average modern textbook. And what we find in most cases, I think it should be admitted, is as debased, worn-out and dogmatic a treatment as could be imagined—incredibly tradition bound, yet lacking in logic and in historical sense alike, and almost without connection to anything else in modern Logic at all. (1970, 12)

Let us consider what came before Hamblin as the traditional approach to fallacies and what comes after him as new approaches. The new approaches (since the 1970’s) show a concern to overcome Hamblin’s criticisms, and they also vie with each to produce the most defensible alternative to the traditional approach. One thing that nearly all the new approaches have in common is that they reject what Hamblin presents as the nearly universally accepted definition of “fallacy” as an argument “that seems to be valid but is not so” (1970, 12). Although this definition of fallacy is not nearly as widely accepted as Hamblin intimated (see Hansen 2002), others have taken to calling it “the standard definition of fallacies” and for convenience we can refer to it as SDF. SDF has three necessary conditions: a fallacy (i) is an argument, (ii) that is invalid, and (iii) appears to be valid. These can be thought of as the argument condition, the invalidity condition and the appearance condition. All three conditions have been brought into question.

Maurice Finocchiaro continued Hamblin’s criticism of the modern textbook treatment of fallacies, observing that they contain very few examples of actual fallacies, leading him to doubt the validity of ‘fallacy’ as a genuine logical category. Although he allows that errors in reasoning are common in real life, he thinks that “types of logically incorrect arguments”—fallacies—are probably not common (1981, 113). For that reason Finocchiaro prefers to speak of fallacious arguments —by which he means arguments in which the conclusion fails to follow from the premises—rather than fallacies (1987, 133). He further distances himself from SDF by not considering the appearance condition.

Finocchiaro distinguishes six ways in which arguments can be fallacious. (1) Formal fallaciousness is simply the case where the conclusion does not follow validly from the premises; this type of error can be demonstrated by producing a suitable analogous counter-example in which the premises are true and the conclusion is false. (2) Explanatory fallaciousness occurs when a specified conclusion follows with no more certainty from the given premises than does a rival conclusion; it occurs most often in the context of proposing explanatory hypotheses. (3) Presuppositional fallaciousness occurs in those cases where an argument depends on a false presupposition; this kind of fallaciousness is demonstrated by making a sound argument showing the presupposition to be false. (4) Positive fallaciousness occurs when the given premises, complemented by other propositions taken as true, are shown to support a conclusion inconsistent with the given conclusion. (5) Semantical fallaciousness results from the ambiguity of terms; the conclusion will follow if the sense given to the term in the premises makes the premises false, but if the other sense is ascribed to the term, making the premises true, the conclusion does not follow (it becomes an instance of formal fallaciousness). (6) Finally, Finocchiaro singles out persuasive fallaciousness , in which the conclusion does not follow from the premises because it is the same as one of the premises. As a test of completeness of this six-fold division of fallaciousness, Finocchiaro (1987) observes that it is adequate to classify all the kinds of errors which Galileo found in the arguments of the defenders of the geocentric view of the solar system.

Gerald Massey (1981) has voiced a strong objection to fallacy theory and the teaching of fallacies. He argues that there is no theory of invalidity—no systematic way to show that an argument is invalid other than to show that it has true premises and a false conclusion (1981, 164). Hence, there is an asymmetry between proving arguments valid and proving them invalid: they are valid if they can be shown to be an instance of a valid form, but they are not proved invalid by showing that they are an instance of an invalid form, because both valid and invalid arguments instantiate invalid forms. Thus, showing that a natural language argument is an instance of an invalid form does not preclude the possibility that it is also an instance of a valid form, and therefore valid. Since upholders of SDF maintain that fallacies are invalid arguments, Massey’s asymmetry thesis has the consequence that no argument can be convicted of being a fallacy on logical grounds. [ 6 ]

The informal logic approach to fallacies is taken in Johnson and Blair’s Logical Self-Defence , a textbook first published in 1977. It was prompted in part by Hamblin’s indictment of the standard treatment and it further develops an initiative taken by Kahane (1971) to develop university courses that were geared to everyday reasoning. Johnson and Blair’s emphasis is on arming students to defend themselves against fallacies in everyday discourse, and a fundamental innovation is in their conception of a good argument. In place of a sound argument—a deductively valid argument with true premises—Johnson and Blair posit an alternative ideal of a cogent argument , one whose premises are acceptable, relevant to and sufficient for its conclusion. Acceptability replaces truth as a premise requirement, and the validity condition is split in to two different conditions, premise relevance and premise sufficiency. Acceptability is defined relative to audiences—the ones for whom arguments are intended—but the other basic concepts, relevance and sufficiency, although illustrated by examples, remain as intuitive, undefined concepts (see Tindale, 2007). Premise sufficiency (strength) is akin to probability in that it is a matter of degree but Johnson and Blair do not pursue giving it numerical expression.

The three criteria of a cogent argument, individually necessary and jointly sufficient, lead to a conception of fallacy as “any argument that violates one of the criteria of good argument … and is committed frequently in argumentative discourse” (1993, 317–18). This shares only one condition with SDF: that a fallacy is an argument. (Deductive) validity is replaced with the broader concept sufficiency, and the appearance condition is not included. Johnson (1987) argued that the appearance condition makes the occurrence of fallacies too subjective since how things appear may vary from perceiver to perceiver, and it should therefore be replaced by a frequency requirement. To be a fallacy, a mistake must occur with sufficient frequency to be worth our attention.

The adoption of the concept of a cogent argument as an ideal has several consequences. The category of fallacies with problematic premises (reminiscent of Whately’s “premises unduly assumed”) shows a concern with argument evaluation over and beyond logical or inference evaluation, drawing the informal logic approach away from purely logical concerns towards an epistemic conception of fallacies. Having both sufficiency and relevance as criteria (instead of the single validity criterion) has the benefit of allowing the making of nuanced judgments about the level of premise support: for example, we might say that an argument’s premises, although insufficient, are nevertheless positively relevant to the conclusion. Irrelevant premise fallacies are those with no premise support at all, whereas insufficient premise fallacies are those in which there is some support, but not enough of it. The informal logicians’ conception of fallacies is meant to be broader and more suitable to natural language argumentation than would be a conception tied only to deductive invalidity.

Johnson and Blair concern themselves exclusively with informal fallacies. Many of the familiar Aristotelian fallacies that are part of the standard treatment are missing from their inventory (e.g., accident, composition and division) and the ones retained find themselves in new categories: begging the question and ambiguity are together under the heading of Problematic Premise; appeals to authority and popularity are placed under the heading of Hasty Conclusion fallacies; ad hominem is among the fallacies that belong in the third category, Fallacies of Irrelevant Reason. This new list of fallacies has a different bent than many earlier lists, being more geared to deal with arguments in popular, everyday communication than philosophical or scientific discourse; this is evident both by the omission of some of the traditional fallacies as well as by the introduction of new ones, such as dubious assumption, two wrongs, slippery slope, and faulty analogy.

The kinds of mistakes one can make in reasoning are generally thought to be beyond enumeration and, hence, it has been maintained that there can be no complete stock of fallacies that will guard against every kind of mistake. Johnson and Blair’s approach is responsive to this problem in that it allows the names of the classes of fallacies — ‘unacceptable premise,’ ‘irrelevant reason’ and ‘hasty conclusion’ — to stand for fallacies themselves, fallacies broad-in-scope; i.e., to serve “both as general principles of organization, and as back-ups to fill in any gaps between specific labels belonging within each genus” (1993, 52). Hence, any violation of one of the criteria of a cogent argument can be considered a fallacy.

In addition to this alternative theoretical approach to fallacies built on the three criteria of a cogent argument—an approach also taken up by others [ 7 ] —informal logic’s contribution to fallacy studies lies in its attempts to provide better analyses of fallacies, a programme pursued by a large number of researchers, including Govier (1982) on the slippery slope, Wreen (1989) on the ad baculum , Walton (1991) on begging the question, Brinton (1995) on the ad hominem , Freeman (1995) on the appeal to popularity, and Pinto (1995) on post hoc ergo propter hoc .

John Woods also despairs of the standard treatment but he sees in it something of importance; namely that the fallacies most often reviewed in introductory level logic textbooks “are a kind of caricature of their associated improprieties, which lie deeply imbedded in human practice” (Woods 1992, 25). The fallacies are then behavioural symptoms of kinds of irrationality to which humans are highly susceptible, and that makes them an important subject for study because they say something about human nature. Therefore, the problem with the standard treatment, according to Woods, is not that it is a misdirected research programme, but rather that it has been poorly carried out, partly because logicians have failed to appreciate that a multi-logical approach is necessary to understand the variety of fallacies. This idea, pursued jointly by Woods and Douglas Walton (1989), is that, for many of the fallacies standard formal logic is inadequate to uncover the unique kind of logical mistakes in question—it is too coarse conceptually to reveal the unique character of many of the fallacies. To get a satisfactory analysis of each of the fallacies they must be matched with a fitting logical system, one that has the facility to uncover the particular logical weakness in question. Inductive logic can be employed for analysis of hasty generalization and post hoc ergo propter hoc ; relatedness logic is appropriate for ignoratio elenchi ; plausible reasoning theory for the ad verecundiam , and dialectical game theory for begging the question and many questions. Woods (1992, 43) refers to this approach to studying the fallacies as methodological pluralism. Thus, like the informal logicians, there is here an interest in getting the analyses of each of the fallacies right, but the Woods and Walton approach involves embracing formal methods, not putting them aside.

Woods (2013) has continued his research on fallacies, most recently considering them in the context of what he calls a naturalized logic (modelled on Quine’s naturalized epistemology). The main point of this naturalizing move is that a theory of reasoning should take into account the abilities and motivations of reasoners. Past work on the fallacies has identified them as failing to satisfy the rules of either deductive or inductive logic, but Woods now wants to consider the core fallacies in light of what he calls third-way reasoning (comparable to non-monotonic reasoning), an account of the cognitive practices that closely resemble our common inferential practices. From the perspective of third-way reasoning the “rules” implicit in the fallacies present themselves as heuristic directives to reasoners rather than as fallacies; hence, it may be that learning from feedback (having errors corrected) is less trouble than learning the rules to avoid fallacies in the first place (Woods 2013, p. 215). Woods illustrates his point by recalling many of the fallacies he originally identified in his 1992 paper, and subjecting them to this revised model of analysis thereby overturning the view that these types of argument are always to be spurned.

SDF may be seen as closely tied to the logical approach to fallacies—the fault in arguments it singles out is their deductive invalidity. But this conception of fallacies turns out to be inadequate to cover the variety of the core fallacies in two ways: it is too narrow because it excludes begging the question which is not invalid, and it is too wide because it condemns good but non-deductive arguments as fallacies (given that they also satisfy the appearance condition) because they are invalid. Even if we replace the invalidity condition in SDF with some less stringent standard of logical weakness which could overcome the “too wide” problem, it would still leave the difficulty of accounting for the fallacy of begging the question unsolved.

Siegel and Biro (1992, 1995) hold an epistemic account of fallacies, contrasting their view with dialectical/rhetorical approaches, because matters extraneous to arguments, such as being a practice that leads to false beliefs or not being persuasive, are not in their view a sufficient condition to make an argument a fallacy. They take the position that “it is a conceptual truth about arguments that their central … purpose is to provide a bridge from known truths or justified beliefs to as yet unknown … truths or as yet unjustified beliefs” (1992, 92). Only arguments that are “epistemically serious” can accomplish this; that is, only arguments that satisfy the extra-formal requirement that premises are knowable independently of their conclusions, and are more acceptable epistemically than their conclusions, can fulfill this function. A purely logical approach to argument will not capture this requirement because arguments of the same valid form, but with different contents, may or may not be epistemically serious, depending on whether the premises are epistemically acceptable relative to the conclusion.

Modifying Biro’s (1977, 265–66) examples we can demonstrate how the requirement of epistemic seriousness plays out with begging the question. Consider these two arguments:

All men are mortal; Obama is a man; So, Obama is mortal.

All members of the committee are old Etonians; Fortesque is a member of the committee; Fortesque is an old Etonian.

In the first argument the premises are knowable independently of the conclusion. The major premise can be deduced from other universal premises about animals, and the minor premise, unlike the conclusion which must be inferred, can be known by observation. Hence, this argument does not beg the question. However, in the second argument (due to Biro, 1977) given the minor premise, the major cannot be known to be true unless the conclusion is known to be true. Consequently, on the epistemic approach to fallacies taken by Biro and Siegel, the second argument, despite the fact that it is valid, is non-serious, it begs the question, and it is a fallacy. If there was some independent way of knowing whether the major premise was true, such as that it was a bylaw that only old Etonians could be committee members, the argument would be a serious one, and not beg the question.

Biro and Siegel’s epistemic account of fallacies is distinguishable in at least three ways. First, it insists that the function of arguments is epistemic, and therefore anything that counts as a fallacy must be an epistemic fault, a breaking of a rule of epistemic justification. But since logical faults are also epistemic faults, the epistemic approach to fallacies will include logical fallacies, although these must also be explicable in terms of epistemic seriousness. Second, since the epistemological approach does not insist that all justification must be deductive, it allows the possibility of their being fallacies (as well as good arguments) by non-deductive standards, something precluded by SDF. Finally, we notice that the appearance condition is not considered a factor in this discussion of fallacies.

Ulrike Hahn and Mike Oaksford (2006a, 2006b) see themselves as contributing to the epistemic approach to fallacy analysis by developing a probabilistic analysis of the fallacies. It is part of their programme for a normative theory of natural language argumentation. They are motivated by what they perceive as the shortcomings in other approaches. The logical (deductive) approach falls short in that it simply divides arguments into valid and invalid arguments thereby failing to appreciate that natural language arguments come in various degrees of strength. The alternative approaches to fallacies, given by procedural (dialectical) and consensual accounts, they criticize on the basis that they fail to address the central problem raised by the fallacies: that of the strength of the reason-claim complex. In Hahn and Oaksford’s view the strength or weakness of the classical fallacies (they are concerned mostly with the post-Aristotelian ones) is not a result of their structure or their context of use. It is instead a matter of the relationship between the evidence and the claim (the contents of the premises and the conclusion). Evaluation of this relationship is thought to be best captured by a probabilistic Bayesian account; accordingly, they adapt Bayes’ theorem to arguments evaluation with the proviso that the probabilities are subjective degrees of belief, not frequencies. “An argument’s strength,” they write, “is a function of an individual’s initial level of belief in the claim, the availability and observation of confirmatory (or disconfirmatory) evidence, and the existence and perceived strength of competing hypotheses” (Corner, et al. 1145). With Korb (2003) they view a fallacy as an argument with a low probability on the Bayesian model.

Since the variance in input probabilities will result in a range of outputs in argument strength, this probabilistic approach has the potential to assign argument strengths anywhere between 0 and 1, thereby allowing that different tokens of one argument type can vary greatly in strength, i.e., some will be fallacies and others not. Also, and this seems to concur with our experience, different arguers may disagree on the strength of the same arguments since they can differ in the assignments of the initial probabilities. Hahn and Oaksford also claim as advantages for their normative theory that it gives guidance for persuasion since it takes into account the initial beliefs of audiences. Moreover, their approach contributes to the study of belief change; that is, to what extent our confidence in the conclusion changes with the availability of new evidence.

Some of the most active new researchers on fallacies take a dialectical and/or dialogical approach. This can be traced back to Hamblin (1970, ch. 8) and Lorenzen’s (1969) dialogue theory. The panacea for fallacies that Whately recommended was more logic; Hamblin, however, proposed a shift from the logical to the dialectical perspective.

[W]e need to extend the bounds of Formal Logic; to include features of dialectical contexts within which arguments are put forward. To begin with, there are criteria of validity of argument that are additional to formal ones: for example, those that serve to proscribe question-begging. To go on with, there are prevalent but false conceptions of the rules of dialogue, which are capable of making certain argumentative moves seem satisfactory and unobjectionable when, in fact, they conceal and facilitate dialectical malpractice. (Hamblin 1970, 254)

The proposal here is to shift the study of fallacies from the contexts of arguments to the contexts of dialogues (argumentation), formulate rules for reasonable dialogue activity, and then connect fallacies to failures of rule-following. Barth and Martens’s paper (1977), which studied the argumentum ad hominem by extending Lorenzen’s dialogue tableaux method to include the definitions of the concepts “line of attack” and “winning strategy,” leads to a conception of fallacies as either failures to meet one of the necessary conditions of rational dialogical argumentation, or failures to satisfy sufficient conditions as specified by production rules of the dialogical method (1977, 96).

The Barth and Martens paper is a bridge between the earlier (quasi-) formal and subsequent informal dialectical theories, and is explicitly acknowledged as a major influence by the Pragma-dialectical theory, the brainchild of Frans van Eemeren and Rob Grootendorst (1984). Rather than beginning from a logical or epistemological perspective they start with the role of argumentation in overcoming interpersonal disagreements. The Pragma-dialecticians propose that inter-personal argumentation can be analysed as two-party-discussions having four analytical stages: a confrontation stage in which the participants become aware of the content of their disagreement; an opening stage in which the parties agree (most likely implicitly) to shared starting points and a set of rules to govern the ensuing discussion; an argumentation stage wherein arguments and doubts about arguments are expressed and recognized; and a final stage in which a decision about the initial disagreement is made, if possible, based on what happened in the argumentation stage.

The Pragma-dialectical theory stipulates a normative ideal of a critical discussion which serves both as a guide to the reconstruction of natural language argumentation, as well as a standard for the evaluation of the analysed product of reconstruction. A set of ten rules has been proposed as constitutive of the critical-discussion ideal, and the proponents of the theory believe that rational arguers would accept them. If followed by both parties to the disagreement, the rules constrain the argumentation decision procedure such that any resolution reached will be deemed reasonable, and “every violation of any of the rules of the discussion procedure for conducting a critical discussion” will be a fallacy (2004, 175). The rules range over all the four stages of argumentation: at the confrontation stage there is a rule which says one may not prevent the other party from expressing their view; for the argumentation stage there is a rule which requires argumentation to be logically strong and in accord with one or another of three general argumentation schemes; at the closing stage there is a rule that the participants themselves are to decide which party was successful based on the quality of the argumentation they have made: if the proponent carries the day, the opponent should acknowledge it, and vice versa .

The Pragma-dialectical theory proposes that each of the core fallacies can be assigned a place as a violation of one of the rules of a critical discussion. For example, the ad baculum fallacy is a form of intimidation that violates the rule that one may not attempt to prevent one’s discussion partner from expressing their views; equivocation is a violation of the rule that formulations in arguments must be clear and unambiguous; post hoc ergo propter hoc violates the rule that arguments must be instances of schemes correctly applied. Moreover, on this theory, since any rule violation is to count as a fallacy this allows for the possibility that there may be hitherto unrecognized “new fallacies.” Among those proposed are declaring a standpoint sacrosanct because that breaks the rule against the freedom to criticize points of view, and evading the burden of proof which breaks the rule that you must defend your standpoint if asked to do so (see van Eemeren 2010, 194).

Clearly not all the rules of critical discussions apply directly to arguments. Some govern other goal-frustrating moves which arguers can make in the course of settling a difference of opinion, such as mis-allocating the burden of proof, asking irrelevant questions, suppressing a point of view, or failing to clarify the meaning of one’s argumentation. In short, the Pragma-dialectical rules of a critical discussion are not just rules of logic or epistemology, but rules of conduct for rational discussants, making the theory more like a moral code than a set of logical principles. Accordingly, this approach to fallacies rejects all three of the necessary conditions of SDF: a fallacy need not be an argument, thus the invalidity condition will not apply either, and the appearance condition is excluded because of its subjective character (Van Eemeren and Grootendorst 2004, 175).

The Pragma-dialectical analysis of fallacies as rule-breakings in a procedure for overcoming disagreements has recently been expanded to take account of the rhetorical dimension of argumentation. Pragma-dialectics takes the rhetorical dimension to stem from an arguer’s wish to have their view accepted which leads dialoguers to engage in strategic maneuvering vis-à-vis their dialogue partners. However, this desire must be put in balance with the dialectical requirement of being reasonable; that is, staying within the bounds of the normative demands of critical discussions. The ways of strategic maneuvering identified are basically three: topic selection, audience orientation, and the selection of presentational devices, and these can be effectively deployed at each stage of argumentation (Van Eemeren 2010, 94). “All derailments of strategic maneuvering are fallacies,” writes van Eemeren (2010, 198), “in the sense that they violate one or more of the rules for critical discussion and all fallacies can be viewed as derailments of strategic maneuvering.” This means that all fallacies are ultimately attributable to the rhetorical dimension of argumentation since, in this model, strategic maneuvering is the entry of rhetoric into argumentation discussions. “Because each fallacy has, in principle, sound counterparts that are manifestations of the same mode of strategic maneuvering” it may not appear to be a fallacy and it “may pass unnoticed” (Van Eemeren 2010, 199). Nevertheless, Pragma-dialectics prefers to keep the appearance condition outside the definition of ‘fallacy’, treating the seeming goodness of fallacies as a sometime co-incidental property, rather than an essential one.

Argumentation evaluation on the Pragma-dialectical approach is done with an eye to a single ideal model of argumentation. This approach has been challenged by Douglas Walton who has written more about fallacies and fallacy theory than anyone else. He has published individual monographs on many of the well-known fallacies, among them, Begging the Question (1991), Slippery Slope Arguments (1992), Ad Hominem Arguments (1998), and a comprehensive work on fallacy theory, A Pragmatic Theory of Fallacy (1995). Over the years his views have evolved. He has referred to his theory as “the Pragmatic theory,” and like the Pragma-dialectical theory it has a dialectical/dialogical basis; however, Walton envisions a number of distinct normative dialectical frameworks (persuasion dialogue, inquiry dialogue, negotiation dialogue, etc.) rather than the single model of a critical discussion proposed by Pragma-dialectics. Postulating different kinds of dialogues with different starting points and different goals, thinks Walton, will bring argumentation into closer contact with argumentation reality. At one point Walton had the idea that fallacies happened when there was an illicit shift from one kind of a dialogue to another (1995, 118–23), for example, using arguments appropriate for a negotiation dialogue in a persuasion dialogue, but more recently he has turned to other ways of explicating fallacies.

Although Walton recognizes the class of formal fallacies, his main interest is in informal fallacies, especially the ones associated with argumentation schemes. The idea of an argumentation scheme is central to Walton’s theory. Schemes are patterns of commonly used kinds of defeasible reasoning/argumentation such as appeals to expert opinion and ad hominem arguments. Schemes do not identify fallacies but rather argument kinds that are sometimes used fairly, and, other times, fallaciously. With each kind of scheme is associated a set of critical questions which guide us in deciding whether a given use of an argument is correct, weak or fallacious. So, if we consider:

\(E\) is an expert in subject area \(S\); \(E\) asserts \(p\) based on \(E\)’s knowledge of \(S\); So, \(p\).

to be the scheme for the appeal-to-expertise kind of argument, [ 8 ] then there will be a question for each premise: Is \(E\) really an expert in \(S\)? Did \(E\) say \(p\) when s/he was acting in her/his professional capacity? (… or did s/he blurt it out while drunk at an association party?). If the answer to both questions is Yes, then the argument creates a presumption for the conclusion—but not a guarantee, for the reasoning is defeasible: other information may come to light that will override the presumption. If one of the questions cannot be answered clearly this is an indication that the argument is weak, and answering No to either of the two questions cancels the presumption for the conclusion, i.e., makes the argument into a bad argument from expert opinion. If the bad argument has “a semblance of correctness about it in [the] context, and poses a serious obstacle to the realization of the goal of the dialog,” then it is a fallacy (2011, 380). [ 9 ]

The definition of fallacy Walton proposes (1995, 255) has five parts. A fallacy:

  • an argument (or at least something that purports to be an argument) that
  • falls short of some standard of correctness;
  • is used in a context of dialogue;
  • has a semblance of correctness about it; and
  • poses a serious problem to the realization of the goal of the dialogue.

Here we find that Walton has relaxed two of the necessary conditions of SDF. Purporting to be an argument is enough (it doesn’t really have to be an argument), while falling short of a standard (one that will vary with the kind of dialogue under consideration) replaces the invalidity condition. However, the appearance condition, here expressed as fallacies having a semblance of correctness about them, remains in full force. The two extra conditions added to fallacy are that they occur only in contexts of dialogue and that they frustrate the realization of the goal of the kind of dialogue in which they occur. In insisting on this dialogical dimension, Walton is in full sympathy with those who think that fallacies can only be rightly analysed within a dialectical framework similar to the ones Aristotle originally studied, and later better defined by Hamblin and Lorenzen. Walton volunteers a shorter version of the definition of a fallacy as “a deceptively bad argument that impedes the progress of a dialogue” (1995, 256).

Walton divides fallacies into two kinds: paralogisms and sophisms. A paralogism is “the type of fallacy in which an error of reasoning is typically committed by failing to meet some necessary requirement of an argumentation scheme” whereas “the sophism type of fallacy is a sophistical tactic used to try to unfairly get the best of a speech partner in an exchange of arguments” (2010, 171; see also 1995, 254). Paralogisms are instances of identifiable argumentation schemes, but sophisms are not. The latter are associated more with infringing a reasonable expectation of dialogue than with failing some standard of argument, (2011, 385; 2010, 175). A further distinction is drawn between arguments used intentionally to deceive and arguments that merely break a maxim of argumentation unintentionally. The former count as fallacies; the latter, less condemnable, are blunders (1995, 235).

Among the informal paralogisms Walton includes: ad hominem , ad populum , ad misericordiam , ad ignorantiam , ad verecundiam , slippery slope, false cause, straw man, argument from consequences, faulty analogy, composition and division. In the category of sophisms he places ad baculum , complex question, begging the question, hasty generalization, ignoratio elenchi , equivocation, amphiboly, accent, and secundum quid . He also has a class of formal fallacies very much the same as those identified by Whately and Copi. The largest class in Walton’s classification is the one associated with argumentation schemes and ad -arguments, and these are the ones that he considers to be the most central fallacies. Nearly all the Aristotelian fallacies included find themselves relegated to the less studied categories of sophisms. Taking a long look at the history of fallacies, then, we find that the Aristotelian fallacies are no longer of central importance. They have been replaced by the fallacies associated with the ad -arguments.

Another recent approach comes from virtue argumentation theory (modelled on virtue epistemology). Virtue argumentation theory is characterized by a distinct set of virtues thought to be essential to good argumentation: willingness to engage in argumentation, willingness to listen to others and willingness to modify one’s own position (see, e.g., Cohen 2009). These may be supplemented with epistemic virtues and even in some cases moral virtues. Although virtues and vices are dispositions of arguers and fallacies are arguments, it is claimed that good argumentation generally results from the influence of argumentation virtues and bad argumentation (including the fallacies) arise because of the vices of arguers.

Taking the Aristotelian view that virtues are a mean between opposite kinds of vices, fallacious arguments can be seen as resulting from arguers moving in one or another direction away from a mean of good argumentation. Aberdein (2013, 2016) especially has developed this model for understanding many of the fallacies. We can illustrate the view by considering appeals to expertise: the associated vices might be too little respect for reliable authorities at one extreme and too much deference to authorities at the other extreme. Aberdein develops the fallacies-as-argumentation-vices analysis in some detail for other of the ad-arguments and sketches how it might be applied to the other core fallacies, suggesting it can profitably be extended to all of them.

All the fallacies, it is claimed, can be fitted in somewhere in the classification of argumentational vices, but the converse is not true although it is possible to bring to light other shortcomings to which we may fall prey in argumentation. Another aspect of the theory is that it distributes argumentation vices among both senders and audiences. Speakers may infect their arguments with vices when they are, for example, closed minded or lack respect for persons, and audiences can contribute to fallaciousness by letting their receptivity be influenced by naïvety, an over-reliance on common sense, or an unfounded bias against a speaker. Perhaps the development of the virtue argumentation theory approach to fallacies provides a supplement to Mill’s theory of fallacies. He distinguished (1891, V, i, 3) what he called the moral (dispositional) and intellectual causes of fallacy. The study of the argumentative vices envisioned above seems best included under the moral study of fallacies as the vices can be taken to be the presdisposing causes to commit intellectual mistakes, i.e., misevaluations of the weight of evidence.

4. Current issues in fallacy theory

A question that continues to dog fallacy theory is how we are to conceive of fallacies. There would be advantages to having a unified theory of fallacies. It would give us a systematic way of demarcating fallacies and other kinds of mistakes; it would give us a framework for justifying fallacy judgments, and it would give us a sense of the place of fallacies in our larger conceptual schemes. Some general definition of ‘fallacy’ is wanted but the desire is frustrated because there is disagreement about the identity of fallacies. Are they inferential, logical, epistemic or dialectical mistakes? Some authors insist that they are all of one kind: Biro and Siegel, for example, that they are epistemic, and Pragma-dialectics that they are dialectical. There are reasons to think that all fallacies do not easily fit into one category.

Together the Sophistical Refutations and Locke’s Essay are the dual sources of our inheritance of fallacies. However, for four reasons they make for uneasy bedfellows. First, the ad fallacies seem to have a built-in dialectical character, which, it can be argued, Aristotle’s fallacies do not have (they are not sophistical refutations but are in sophistical refutations). Second, Aristotle’s fallacies are logical mistakes: they have no appropriate employment outside eristic argumentation whereas the ad -fallacies are instances of ad -arguments, often appropriately used in dialogues. Third, the appearance condition is part of the Aristotelian inheritance but it is not intimately connected with the ad -fallacies tradition. A fourth reason that contributes to the tension between the Aristotelian and Lockean traditions in fallacies is that the former grew out of philosophical problems, largely what are logical and metaphysical puzzles (consider the many examples in Sophistical Refutations ), whereas the ad -fallacies are more geared to social and political topics of popular concern, the subject matter that most intrigues modern researchers on fallacy theory.

As we look back over our survey we cannot help but observe that fallacies have been identified in relation to some ideal or model of good arguments, good argumentation, or rationality. Aristotle’s fallacies are shortcomings of his ideal of deduction and proof, extended to contexts of refutation. The fallacies listed by Mill are errors of reasoning in a comprehensive model that includes both deduction and induction. Those who have defended SDF as the correct definition of ‘fallacy’ [ 10 ] take logic simpliciter or deductive validity as the ideal of rationality. Informal logicians view fallacies as failures to satisfy the criteria of what they consider to be a cogent argument. Defenders of the epistemic approach to fallacies see them as shortfalls of the standards of knowledge-generating arguments. Finally, those who are concerned with how we are to overcome our disagreements in a reasonable way will see fallacies as failures in relation to ideals of debate or critical discussions.

The standard treatment of the core fallacies has not emerged from a single conception of good argument or reasonableness but rather, like much of our unsystematic knowledge, has grown as a hodgepodge collection of items, proposed at various time and from different perspectives, that continues to draw our attention, even as the standards that originally brought a given fallacy to light are abandoned or absorbed into newer models of rationality. Hence, there is no single conception of good argument or argumentation to be discovered behind the core fallacies, and any attempt to force them all into a single framework, must take efforts to avoid distorting the character originally attributed to each of them.

From Aristotle to Mill the appearance condition was an essential part of the conception of fallacies. However, some of the new, post-Hamblin, scholars have either ignored it (Finocchiaro, Biro and Siegel) or rejected it because appearances can vary from person to person, thus making the same argument a fallacy for the one who is taken in by the appearance, and not a fallacy for the one who sees past the appearances. This is unsatisfactory for those who think that arguments are either fallacies or not. Appearances, it is also argued, have no place in logical or scientific theories because they belong to psychology (van Eemeren and Grootendorst, 2004). But Walton (e.g., 2010) continues to consider appearances an essential part of fallacies as does Powers (1995, 300) who insists that fallacies must “have an appearance, however quickly seen through, of being valid.” If the mistake in an argument is not masked by an ambiguity that makes it appear to be a better argument than it really is, Powers denies it is a fallacy.

The appearance condition of fallacies serves at least two purposes. First, it can be part of explanations of why reasonable people make mistakes in arguments or argumentation: it may be due in part to an argument’s appearing to be better than it really is. Second, it serves to divide mistakes into two groups: those which are trivial or the result of carelessness (for which there is no cure other than paying better attention), and those which we need to learn to detect through an increased awareness of their seductive nature. Without the appearance condition, it can be argued, no division can be made between these two kinds of errors: either there are no fallacies or all mistakes in argument and/or argumentation are fallacies; a conclusion that some are willing to accept, but which runs contrary to tradition. One can also respond that there is an alternative to using the appearance condition as the demarcation property between fallacies and casual mistakes, namely, frequency. Fallacies are those mistakes we must learn to guard against because they occur with noticeable frequency. To this it may be answered that ‘noticeable frequency’ is vague, and is perhaps best explained by the appearance condition.

On the more practical level, there continues to be discussion about the value of teaching the fallacies to students. Is it an effective way for them to learn to reason well and to avoid bad arguments? One reason to think that it is not effective is that the list of fallacies is not complete, and that even if the group of core fallacies was extended to incorporate other fallacies we thought worth including, we could still not be sure that we had a complete prophylactic against bad arguments. Hence, we are better off teaching the positive criteria for good arguments/ argumentation which give us a fuller set of guidelines for good reasoning. But some (Pragma-dialectics and Johnson and Blair) do think that their stock of fallacies is a complete guard against errors because they have specified a full set of necessary conditions for good arguments/argumentation and they hold that fallacies are just failures to meet one of these conditions.

Another consideration about the value of the fallacies approach to teaching good reasoning is that it tends to make students overly critical and lead them to see fallacies where there are not any; hence, it is maintained we could better advance the instilling of critical thinking skills by teaching the positive criteria of good reasoning and arguments (Hitchcock, 1995). In response to this view, it is argued that, if the fallacies are taught in a non-perfunctory way which includes the explanations of why they are fallacies—which normative standards they transgress—then a course taught around the core fallacies can be effective in instilling good reasoning skills (Blair 1995).

Recently there has been renewed interest in how biases are related to fallacies. Correia (2011) has taken Mill’s insight that biases are predisposing causes of fallacies a step further by connecting identifiable biases with particular fallacies. Biases can influence the unintentional committing of fallacies even where there is no intent to be deceptive, he observes. Taking biases to be “systematic errors that invariably distort the subject’s reasoning and judgment,” the picture drawn is that particular biases are activated by desires and emotions (motivated reasoning) and once they are in play, they negatively affect the fair evaluation of evidence. Thus, for example, the “focussing illusion” bias inclines a person to focus on just a part of the evidence available, ignoring or denying evidence that might lead in another direction. Correia (2011, 118) links this bias to the fallacies of hasty generalization and straw man, suggesting that it is our desire to be right that activates the bias to focus more on positive or negative evidence, as the case may be. Other biases he links to other fallacies.

Thagard (2011) is more concerned to stress the differences between fallacies and biases than to find connections between them. He claims that the model of reasoning articulated by informal logic is not a good fit with the way that people actually reason and that only a few of the fallacies are relevant to the kinds of mistakes people actually make. Thagard’s argument depends on his distinction between argument and inference. Arguments, and fallacies, he takes to be serial and linguistic, but inferences are brain activities and are characterized as parallel and multi-modal. By “parallel” is meant that the brain carries out different processes simultaneously, and by “multi-modal” that the brain uses non-linguistic and emotional, as well as linguistic representations in inferring. Biases (inferential error tendencies) can unconsciously affect inferring. “Motivated inference,” for example, “involves selective recruitment and assessment of evidence based on unconscious processes that are driven by emotional considerations of goals rather than purely cognitive reasoning” (2011, 156). Thagard volunteers a list of more than fifty of these inferential error tendencies. Because motivated inferences result from unconscious mental processes rather than explicit reasoning, the errors in inferences cannot be exposed simply by identifying a fallacy in a reconstructed argument. Dealing with biases requires identification of both conscious and unconscious goals of arguers, goals that can figure in explanations of why they incline to particular biases. “Overcoming people’s motivated inferences,” Thagard concludes, “is therefore more akin to psychotherapy than informal logic” (157), and the importance of fallacies is accordingly marginalized.

In response to these findings, one can admit their relevance to the pedagogy of critical thinking but still recall the distinction between what causes mistakes and what the mistakes are. The analysis of fallacies belongs to the normative study of arguments and argumentation, and to give an account of what the fallacy in a given argument is will involve making reference to some norm of argumentation. It will be an explanation of what the mistake in the argument is. Biases are relevant to understanding why people commit fallacies, and how we are to help them get past them, but they do not help us understand what the fallacy-mistakes are in the first place—this is not a question of psychology. Continued research at this intersection of interests will hopefully shed more light on both biases and fallacies.

  • Aberdein, A., 2013, “Fallacy and argumentational vice,” Ontario Society for the Study of Argumentation (OSSA Conference Archive: OSSA 10), available online .
  • –––, 2016, “The vices of argument,” Topoi , 25: 413–22.
  • Aristotle, Categories , H.P. Cooke (trans.), Cambridge, MA: Harvard University Press, 1938.
  • –––, On Sophistical Refutations , E. S. Forster (trans.), Cambridge, MA: Harvard University Press, 1955.
  • –––, Posterior Analytics , H. Tredennick (trans.), Cambridge, MA: Harvard University Press, 1960.
  • –––, Topics , Books I and VIII , R. Smith (trans.), Oxford: Clarendon Press, 1997.
  • Arnauld, A., and P. Nicole, 1685, Logic, or the Art of Thinking , 5 th edition, J. V. Buroker (trans.), Cambridge: Cambridge University Press, 1996.
  • Bachman, J., 1995, “Appeal to authority,” in Hansen and Pinto, 1995, pp. 274–86.
  • Bacon, F., 1620, The New Organon , Indianapolis: Bobbs-Merrill, 1960.
  • Barth, E. M., and J. L. Martens, 1977, “ Argumentum ad hominem , from chaos to formal dialectic,” Logique et Analyse , 20: 76–96.
  • Bentham, J., 1824, The Handbook of Political Fallacies , page references to reprint, H. A. Larrabee (ed.), New York: Harper and Brothers, 1962.
  • Biro, J., 1977, “Rescuing ‘begging the question’,” Metaphilosophy , 8: 257–71.
  • Biro, J., and H. Siegel, 1992, “Normativity, argumentation and an epistemic theory of fallacies,” in Frans H. van Eemeren, et al., editors, Argumentation Illuminated , Amsterdam: Sic Sat, pp. 85–103.
  • –––, 1997, “Epistemic normativity, argumentation and fallacies,” Argumentation , 11: 277–293.
  • –––, 2006, “In defence of the objective epistemic approach to argumentation,” Informal Logic , 26: 91–102.
  • Blair, J. A., 1995, “The place of teaching informal fallacies in teaching reasoning skills or critical thinking,” in Hansen and Pinto 1995, pp. 328–38.
  • Brinton, A., 1995, “The ad hominem ,” in Hansen and Pinto 1995, pp. 213–22.
  • Churchill, R. P., 1986, Becoming Logical , New York: St Martin’s Press.
  • Cohen, D.H., 2009, “Keeping an open mind and having a sense of proportion as virtues in argumentation,” Cogency , 1: 49–64.
  • Copi, I. M., 1961, Introduction to Logic , (2 nd ed.), New York: Macmillan.
  • Corcoran, J., 1974, “Remarks on Stoic deduction,” in J. Corcoran (ed.), Ancient Logic and its Modern Interpretations , Dordrecht: Reidel, pp. 169–81.
  • Corner, A., U. Hahn, and M. Oaksford, 2006, “The slippery slope argument—probability, utility and category reappraisal,” Proceedings of the Annual Meeting of the Cognitive Science Society , 28: 1145–1150, available online .
  • Correia, V., 2011, “Biases and fallacies: The role of motivated irrationality in fallacious reasoning,” Cogency , 3: 107–26.
  • Finocchiaro, M. A., 1974, “The concept of ad hominem argument in Galileo and Locke,” Philosophical Forum , 5: 394–404; page references are to Finocchiaro 2005, pp. 329–39.
  • –––, 1981, “Fallacies and the evaluation of reasoning,” American Philosophical Quarterly 18: 13–22; page references are to Finocchiaro 2005, pp. 109–27.
  • –––, 1987, “Six types of fallaciousness: towards a realistic theory of logical criticism,” Argumentation 1: 263–82; page references are to Finocchiaro 2005, pp. 128–47.
  • –––, 2005, Arguments about Arguments . Cambridge: Cambridge University Press.
  • Freeman, J. B., 1988, Thinking Logically: Basic Concepts for Reasoning , Englewood Cliffs: Prentice-Hall.
  • –––, 1995, “The appeal to popularity and presumption by common knowledge,” in Hansen and Pinto 1995, pp. 265–73.
  • Goodwin, J., 1998, “Forms of authority,” Argumentation , 12: 267–80.
  • Govier, T., 1982, “What’s wrong with slippery slope fallacies?” Canadian Journal of Philosophy , 12: 303–16.
  • –––, 1987, “Four reasons there are no fallacies?” in Problems in Argument Analysis and Evaluation , Dordrecht: Foris; page references to reprint as “Reply to Massey” in Hansen and Pinto 1995, pp. 172–80.
  • –––, 1988, A Practical Study of Argument , 2nd edition, Belmont: Wadsworth.
  • Grootendorst, R., 1997, “Jeremy Bentham’s Handbook of Political Fallacies ,” in Historical Foundations of Informal Logic , D. Walton and A. Brinton (eds.), Aldershot: Ashgate, pp. 114–24.
  • Hahn, U., and M. Oaksford, 2006a, “A normative theory of argument strength,” Informal Logic , 26: 1–24.
  • –––, 2006b, “A Bayesian approach to informal argument fallacies,” Synthese , 152: 207–236.
  • Hamblin, C. L., 1970, Fallacies , London: Methuen.
  • Hansen, H. V., 2002, “The straw thing of fallacy theory: the standard definition of ‘fallacy’,” Argumentation , 16: 134–55.
  • –––, 2006, “Whately on arguments involving authority,” Informal logic , 26: 319–40.
  • –––, and R. C. Pinto (eds.), 1995, Fallacies: Classical and Contemporary Readings , University Park: Penn State Press.
  • Hintikka, J., 1987, “The fallacy of fallacies,” Argumentation , 1: 211–38.
  • –––, 1997, “What was Aristotle doing in his early logic, anyway? A reply to Woods and Hansen,” Synthese , 113: 241–49.
  • Hitchcock, D., 1995, “Do fallacies have a place in the teaching of reasoning skills or critical thinking?” in Hansen and Pinto 1995, pp. 319–27.
  • –––, 2000, “Fallacies and formal logic in Aristotle,” History and Philosophy of Logic , 21: 2017–21.
  • Irwin, T., and G. Fine, 1996, Aristotle, Introductory Readings , Indianapolis: Hackett.
  • –––, 1987, “The blaze of her splendors: Suggestions about revitalizing fallacy theory,” Argumentation , 1: 239–53; page references to reprint in Hansen and Pinto 1995, pp. 107–19.
  • Johnson, R., and J. A. Blair, 1993, Logical Self-Defence , 3 rd ed., Toronto: McGraw-Hill Ryerson.
  • Johnstone, H. W., Jr., 1952, “Philosophy and argumentum ad hominem ,” Journal of Philosophy , 49: 489–98.
  • Kahane, H., 1971, Logic and Contemporary Rhetoric , Belmont: Wadsworth.
  • Korb, K., 2003, “Bayesian informal logic and fallacy,” Informal Logic , 23: 41–70.
  • Krabbe, E. C. W., 1995, “Appeal to ignorance,” in Hansen and Pinto 1995, pp. 251–64.
  • Locke, J., 1690, An Essay Concerning Human Understanding . Many editions.
  • Lorenzen, P., 1969, Normative Logic and Ethics , Mannheim: Bibliographisches Institut; 2nd annotated edition, 1984.
  • Massey, G. J., 1981, “The fallacy behind fallacies,” Midwest Studies in Philosophy , 6: 489–500; page references are to reprint in Hansen and Pinto 1995, pp. 159–71.
  • Mates, B., 1965, Elementary Logic , Oxford: Oxford University Press.
  • Mill, J. S., 1891, A System of Logic, Ratiocinative and Inductive , 8 th edition, New York: Harper and Brothers; first edition 1843.
  • Nuchelmans, G., 1993, “On the fourfold root of argumentum ad hominem ,” in E. C. W. Krabbe, R. J. Dalitz, and P. A. Smit (eds.), Empirical Logic and Public Debate , Amsterdam: Rodopi, pp. 37–47.
  • Pinto, R. C., 1995, Post hoc, ergo propter hoc , in Hansen and Pinto, pp. 302–11.
  • Powers, L., 1995, “Equivocation,” in Hansen and Pinto 1995, pp. 287–301.
  • Rosen, F., 2006, “The philosophy of error and liberty of thought: J. S. Mill on logical fallacies,” Informal Logic , 26: 121–47.
  • Salmon, W., 1963, Logic , Englewood-Cliffs: Prentice-Hall.
  • Schreiber, S. G., 2003, Aristotle on False Reasoning , Albany: State University of New York Press.
  • Smith, R., 1997, “Commentary,” Aristotle: Topics, Books I and VIII , Oxford: Clarendon Press.
  • Thagard, P., 2011, “Critical thinking and informal logic: neuropsychological perspectives,” Informal Logic , 31: 152–70.
  • Tindale, C. W., 1996, “Fallacies in transition: An assessment of the Pragma-dialectical perspective,” Informal Logic , 18: 17–33.
  • –––, 2007, “On Fallacy,” in Reason Reclaimed: Essays in Honor of J. Anthony Blair and Ralph H. Johnson , H.V. Hansen and R. C. Pinto (eds.), Newport News: Vale Press, pp. 155–70.
  • Van Eemeren, F. H., 2010, Strategic Maneuvering in Argumentative Discourse , Amsterdam: John Benjamins.
  • –––, and Rob Grootendorst, 1984, Speech Acts in Argumentative Discussions , Dordrecht: Foris.
  • –––, 1992, Argumentation, Communication and Fallacies , Hillsdale: Erlbaum.
  • –––, 2004, A Systematic Theory of Argumentation , Cambridge: Cambridge University Press.
  • Walton, D. N., 1991, Begging the Question , New York: Greenwood.
  • –––, 1995, A Pragmatic Theory of Fallacies , Tuscaloosa: University of Alabama Press.
  • –––, 1998, Ad hominem arguments , Tuscaloosa, University of Alabama Press.
  • –––, 2010, “Why fallacies appear to be better arguments than they are,” Informal Logic , 30: 159–84.
  • –––, 2011, “Defeasible reasoning and informal fallacies,” Synthese , 179: 377–407.
  • Watts, I., 1796, Logick: or, the Right Use of Reason , 2 nd edition; page references to reprint, New York: Garland, 1984.
  • Whately, R., 1875, Elements of Logic , 9 th ed., London: Longmans, Green and Company; first edition 1826.
  • Woods, J., 1992, “Who cares about the fallacies?” in Argumentation Illuminated , F. H. van Eemeren, et al. (eds.), Amsterdam: SicSat, pp. 23–48.
  • –––, 2013, Errors of Reasoning: Naturalizing the Logic of Inference , London: College Publications.
  • –––, and H. V. Hansen, 1997, “Hintikka on Aristotle’s fallacies,” Synthese , 113: 217–39.
  • –––, 2001, “The subtleties of Aristotle on non-cause,” Logique et analyse , 176: 395–415.
  • Woods, J., and D. N. Walton, 1989, Fallacies: Selected Papers, 1972–1982 , Dordrecht: Foris.
  • Wreen, M., 1989, “A bolt of fear,” Philosophy and Rhetoric , 22: 131–40.
How to cite this entry . Preview the PDF version of this entry at the Friends of the SEP Society . Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO). Enhanced bibliography for this entry at PhilPapers , with links to its database.
  • Curtis, Gary N., Fallacy Files
  • Dowden, Bradley, Fallacies , entry in the Internet Encyclopedia of Philosophy .
  • Hansen, H.V., and C. Fioret, 2016. A searchable bibliography of fallacies—2016 , Informal Logic , 36: 432–72.
  • Informal Logic , an open-access journal.
  • Labossiere, Michael C., Fallacies , hosted by The Nizkor Project.
  • RAIL , a blog about Reasoning, Argumentation, and Informal Logic.

logic: informal | relativism

Acknowledgments

The author would like to thank the executive and subject editors who suggested a way to improve the discussion of begging the question .

Copyright © 2020 by Hans Hansen < hhansen @ uwindsor . ca >

  • Accessibility

Support SEP

Mirror sites.

View this site from another server:

  • Info about mirror sites

The Stanford Encyclopedia of Philosophy is copyright © 2023 by The Metaphysics Research Lab , Department of Philosophy, Stanford University

Library of Congress Catalog Data: ISSN 1095-5054

Academia.edu no longer supports Internet Explorer.

To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to  upgrade your browser .

Enter the email address you signed up with and we'll email you a reset link.

  • We're Hiring!
  • Help Center

paper cover thumbnail

Logical Fallacies: How They Undermine Critical Thinking and How to Avoid Them

Profile image of Hershey H Friedman

This paper explains how to recognize and steer clear of numerous common logical fallacies, ranging from ad hominem arguments to wishful thinking, that can damage an argument. Critical thinking is essential in the digital age, where we must question false or flawed claims. It helps us base our decisions on facts and evidence, not feelings or fallacious reasoning. Unfortunately, many employers struggle to find workers with this skill. To develop it, one must learn how to understand and evaluate the essence of an argument.

Related Papers

claudia cuadro

critical thinking and logical fallacies

rohmani indah

Critical thinking skill has been a crucial issue in the context of higher education as the benchmark of qualified graduates. It is integrated in all aspects and involved in all of the courses as elaborated in the syllabus. Assessing the critical thinking becomes prominent to make sure that its quality is maintained. The real reflection of critical thinking can be traced through students’ ability to express their thought in the form of arguments. Good arguments must be supported not only by convincing claims and careful choice of supporting details but also on the rhetorical pattern which is free from fallacious statements. Identifying the fallacious statement which include recognizing the fallacy varieties assures the quality of their critical thinking. This study investigates the fallacious statements in the argumentative writing of the students of UIN Maulana Malik Ibrahim Malang who argue on global issues. The faulty reasoning is found in terms of the the discussion on the topics...

Charlene Tan

This chapter introduces key concepts in critical thinking using films and music videos. It focuses on the critical thinking skills needed for the identification, analysis and evaluation of arguments. Based on 12 key questions, readers are introduced to core features of an argument such as “premise”, “conclusion” and “assumption”. The main types of arguments and the criteria for evaluating these arguments are also discussed. Throughout the chapter, films such as A Beautiful Mind, Bowling for Columbine and CSI: Miami, and music videos of John Lennon’s “Imagine”, Britney Spears’ “Toxic”, Michael Jackson’s “Billie Jean” and others are used to illustrate the concepts.

Abdulvahit Çakır

The aim of this study was to explore the impact of raising awareness about reasoning fallacies on the development of critical reading skills of the first grade students in the ELT department, Gazi Faculty of Education. It was evaluated via a 56-question reasoning fallacies test confining seven questions to each fallacy studied in this research. Although there are numerous kinds of fallacies, between 14 and 191 to be more precise, the common ones were chosen in accordance with the reasoning fallacies test for practical reasons. In addition to this, during the literature review, some other common fallacies were determined and included in this dissertation. This study compared the students trained explicitly about questioning the arguments and argumentative texts on the one side and the students in the ordinary reading classes following the regular syllabus in terms of awareness about reasoning fallacies. A true experimental design was used to collect data through pre- and post-tests. ...

Robert Gass

The ability to think, reason, and argue well depends, among other things, on students’ ability to identify and avoid informal fallacies. This exercise enhances students’ understanding of fallacies through an experiential activity in which they construct fallacies on their own and identify fallacies created by other students. In the process, they consider the ethical and practical considerations of encountering fallacies in &quot;real life.&quot; The exercise can be used in a variety of college courses, including public speaking, logic, debate, argumentation, critical thinking, writing, rhetoric, and others.

Sandra Dwyer

Hal Campbell

Critical thinking by definition can be explained as the determination of whether we should accept, reject, or suspend judgment about a claim and the degree of confidence with which we should accept or reject it. Critical thinking helps us to formulate a judgment as to whether a position, theory, or idea is incomplete or unclear, insufficiently supported by the contentions made in its behalf, or whether the argument is unconvincing, or simply wrong. One of the principle tenants of critical thinking is that the ideas, arguments, and conclusions being offered are critiqued and not the person making them. As you can tell from the dogma and discourse going on in the media these days, this isn’t a widely embraced approach amongst politicians, pundits, reporters, and the general public. It is perfectly acceptable to come to a conclusion about the person making the argument, but that comes much later and is based upon the position they took on the issue and the rationale they used to argue their point. It is also a measure of how often they are perceived as inaccurate, uninformed, or simply incorrect about an issue that they postulate, and what strategies they use routinely to manipulate the people they are endeavoring to persuade to their point of view.

Inquiry: Critical Thinking Across the Disciplines

Sharon Bailin , Mark Battersby

Sabina Saldanha

RELATED PAPERS

javier rios

Joel Ñaña Escobar

I fórum imuê - A abordagem etnográfica e o desafio das composições coletivas

Catarina Morawska Vianna

International Journal of Information Systems for Crisis Response and Management

Mohamed Magdy

Athletic Therapy Today

Karen Hostetter

Tuomas Knowles

Atherosclerosis

J.H.J. Muntinga

Frontiers in Ecology and Evolution

Louise Shelley

一模一样加拿大范莎学院毕业证 uofs文凭证书英文录取通知原版一模一样

Social Science Research Network

Sonja Dobkowitz

Paper Bag Murah Ziplock

dika tuwagapat

BMB Reports

mahboobeh nazari

eman kolieb

ghjtftgd ghhtrf

ACS Applied Materials &amp; Interfaces

Michitoshi Hayashi

Bulletin of Electrical Engineering and Informatics

Asian Journal of Economics, Business and Accounting

PETER SIMOTWO

Rheumatology (Oxford, England)

Philippe Chalem

yosef haviv

II International Conference on Landscape and Urban Horticulture

M. Devecchi

哪里买curtin毕业证 科廷科技大学毕业证文凭学历证书Leter Offer原版一模一样

RELATED TOPICS

  •   We're Hiring!
  •   Help Center
  • Find new research papers in:
  • Health Sciences
  • Earth Sciences
  • Cognitive Science
  • Mathematics
  • Computer Science
  • Academia ©2024

Library homepage

  • school Campus Bookshelves
  • menu_book Bookshelves
  • perm_media Learning Objects
  • login Login
  • how_to_reg Request Instructor Account
  • hub Instructor Commons

Margin Size

  • Download Page (PDF)
  • Download Full Book (PDF)
  • Periodic Table
  • Physics Constants
  • Scientific Calculator
  • Reference & Cite
  • Tools expand_more
  • Readability

selected template will load here

This action is not available.

Humanities LibreTexts

2.5: Logical Fallacies - How to Spot Them and Avoid Making Them

  • Last updated
  • Save as PDF
  • Page ID 20616

  • Athena Kashyap & Erika Dyquisto
  • City College of San Francisco via ASCCC Open Educational Resources Initiative

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

\( \newcommand{\Span}{\mathrm{span}}\)

\( \newcommand{\id}{\mathrm{id}}\)

\( \newcommand{\kernel}{\mathrm{null}\,}\)

\( \newcommand{\range}{\mathrm{range}\,}\)

\( \newcommand{\RealPart}{\mathrm{Re}}\)

\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

\( \newcommand{\Argument}{\mathrm{Arg}}\)

\( \newcommand{\norm}[1]{\| #1 \|}\)

\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

\( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

\( \newcommand{\vectorC}[1]{\textbf{#1}} \)

\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

Logical Fallacies -- Definition

As you rewrite, review, and revise your logical argument, be aware of logical fallacies, or common errors in thinking that can weaken a logical argument.

Fallacies are errors or tricks of reasoning. We can call a fallacy an error of reasoning if it occurs accidentally; we call it a trick of reasoning if a speaker or writer uses it in order to deceive or manipulate the audience. Fallacies can be either formal or informal.

critical thinking and logical fallacies

(Decorative image of a traffic sign that says "Oops!") Image authored by Cripi on Pixabay. CC0: No Rights Reserved

Most formal fallacies are errors of logic: the conclusion doesn’t really follow from, or is not supported by, the premises. Either the premises are untrue or the argument is invalid. For example, the following argument contains an error in assuming that one thing and only that one thing causes a particular outcome: “Nora feeds Johnny eggplant every day, and Johnny is really healthy; therefore, we should feed our Sally more eggplant.” While it may be true that eggplant is a healthy food, Johnny’s eggplant consumption is assuredly not the only factor contributing to his health. So it does not necessarily follow that Sally should also eat eggplant every day. Formal fallacies are created when the relationship between premise and conclusion does not hold up, or when premises are unsound.

Informal fallacies take many forms and are widespread in everyday discourse. Very often they involve bringing irrelevant information into an argument, or are based on assumptions that, when examined, prove to be incorrect. For example, the following statement plays inaccurately to authority by assuming that one person only knows best, without bringing facts, multiple informed expert opinions, or relevant research into the argument: “Our governor supports a single-payer health care system for the state, so we should, too.” While the governor may have information about health care that the average citizen does not have access to, merely the fact that the governor supports a particular cause is not a reason to agree. Informal fallacies often result from the misuse of language and/or evidence.

Whether a fallacy is an error or a trick, whether it is formal or informal, its use undercuts the validity and soundness of any argument. For example, if someone defines a key term in her argument in an ambiguous, vague, or circular way, her argument will appear very weak to a critical audience.

In addition, when listeners or readers spot questionable reasoning or unfair attempts at audience manipulation, more than the author’s argument ( logos ) may be compromised. Their evaluation of the credibility of the speaker/writer ( ethos ), and perhaps their ability to connect with that speaker on the level of shared values ( pathos ), also may be compromised. At the very least, the presence of fallacies will suggest to an audience that the speaker or writer lacks argumentative skill.

Evaluating an Argument for Logical Fallacies

arrows-1262403_1920-300x212.png

One way to go about evaluating an argument for fallacies is to return to the concept of the three types of support for claims: ethos, logos, and pathos.

As a quick reminder,

  • Ethos is an argument that appeals to ethics, authority, and/or credibility.
  • Logos is an argument that appeals to logic.
  • Pathos is an argument that appeals to emotion.

Classifying fallacies as fallacies of ethos, logos, or pathos will help you both to understand their nature and to recognize them when you encounter them. Please keep in mind, however, that some fallacies may fit into multiple categories.

  • Fallacies of ethos relate to credibility. These fallacies may unfairly build up the credibility of the author (or the author's allies) or unfairly attack the credibility of the author’s opponent (or allies).
  • Fallacies of logos give an unfair advantage to the claims of the speaker or writer or an unfair disadvantage to his opponent’s claims.
  • Fallacies of pathos rely excessively upon emotional appeals, attaching positive associations to the author’s argument and negative ones to his opponent’s position.

Evaluating an Appeal to Ethos

When you evaluate an appeal to ethos, you examine how successfully a speaker or writer establishes authority or credibility with her intended audience. You are asking yourself what elements of the essay or speech would cause an audience to feel that the author is (or is not) trustworthy and credible.

A good speaker or writer leads the audience to feel comfortable with her knowledge of a topic. The audience sees her as someone worth listening to—a clear or insightful thinker, or at least someone who is well-informed and genuinely interested in the topic.

Some of the questions you can ask yourself as you evaluate an author’s ethos may include the following:

  • Has the writer or speaker cited her sources or in some way made it possible for the audience to access further information about the issue?
  • Does she demonstrate familiarity with different opinions and perspectives?
  • Does she provide complete and accurate information about the issue?
  • Does she use the evidence fairly? Does she avoid selective use of evidence or other types of manipulation of data?
  • Does she speak respectfully about people who may have opinions and perspectives different from her own?
  • Does she use unbiased language?
  • Does she avoid excessive reliance on emotional appeals?
  • Does she accurately convey the positions of people with whom she disagrees?
  • Does she acknowledge that an issue may be complex or multifaceted?
  • Does her education or experience give her credibility as someone who should be listened to on this issue?

Some of the above questions may strike you as relevant to an evaluation of logos as well as ethos—questions about the completeness and accuracy of information and whether it is used fairly. In fact, illogical thinking and the misuse of evidence may lead an audience to draw conclusions not only about the person making the argument but also about the logic of an argument.

Recognizing a Manipulative Appeal to Ethos

In a perfect world, everyone would tell the truth and we could depend upon the credibility of speakers and authors. Unfortunately, that is not always the case. You would expect that news reporters would be objective and tell new stories based upon the facts. Janet Cooke, Stephen Glass, Jayson Blair, and Brian Williams all lost their jobs for plagiarizing or fabricating parts of their news stories. Janet Cooke’s Pulitzer Prize was revoked after it was discovered that she made up “Jimmy,” an eight-year old heroin addict. Brian Williams was fired as anchor of the NBC Nightly News for exaggerating his role in the Iraq War.

Others have become infamous for claiming academic degrees that they didn’t earn, as in the case of Marilee Jones. At the time of discovery, she was Dean of Admissions at Massachusetts Institute of Technology (MIT). After 28 years of employment, it was determined that she never graduated from college. However, on her website she is still promoting herself as “a sought after speaker, consultant and author” and “one of the nation’s most experienced College Admissions Deans."

Beyond lying about their own credentials, authors may employ a number of tricks or fallacies to lure you to their point of view. Some of the more common techniques are described below. When you recognize these fallacies being committed, you should question the credibility of the speaker and the legitimacy of the argument. If you use these when making your own arguments, be aware that they may undermine or destroy your credibility.

Fallacies that Misuse an Appeal to Ethos

Ad hominem : attacking the person making an argument rather than the argument itself. Latin for “argument against the person” or “argument toward the person.” Basically, an ad hominem argument goes like this: Person 1 makes claim X. There is something objectionable about Person 1. Therefore claim X is false.

4550001017_4b6bb02d83_z.jpg

False authority : relying on claims of expertise when the claimed expert (a) lacks adequate background/credentials in the relevant field, (b) departs in major ways from the consensus in the field, or (c) is biased, e.g., has a financial stake in the outcome.

Example: “Dr. X is an engineer, and he doesn’t believe in global warming.”

Guilt by association : linking the person making an argument to an unpopular person or group.

Example: “My opponent is a card-carrying member of the Communist Party.”

Poisoning the well: undermining an opponent’s credibility before they get a chance to speak.

Example: “The prosecution is going to bring up a series or so-called experts who are getting a lot of money to testify here today.”

Transfer fallacy : associating the argument with someone or something popular or respected; hoping that the positive associations will “rub off” onto the argument.

Examples: In politics, decorating a stage with red, white, and blue flags and bunting; in advertising, using pleasant or wholesome settings as the backdrop for print or video ads.

Name-calling : labeling an opponent with words that have negative connotations in an effort to undermine the opponent’s credibility.

Example: “These rabble-rousers are nothing but feminazis.”

Plain folk : presenting yourself as (or associating your position with) ordinary people with whom you hope your audience will identify; arguers imply that they or their supporters are trustworthy because they are "common people" rather than members of the elite.

Example: “Who would you vote for—someone raised in a working-class neighborhood who has the support of Joe the Plumber or some elitist whose daddy sent him to a fancy school?”

Testimonial fallacy (argument from authority) : inserting an endorsement of the argument by someone who is popular or respected but who lacks expertise or authority in the area under discussion.

Example: “I’m not a doctor, but I play one on TV”—a famous example of a celebrity endorsement for a cough syrup (Deis, 2011, n.p.).

4557131838_e482a77b84_z.jpg

The most general structure of this argument runs something like the following: Person A claims that Person A is a respected scientist or other authority; therefore, the claim they make is true.

Evaluating an Appeal to Logos

When you evaluate an appeal to logos, you consider how logical the argument is and how well-supported it is in terms of evidence. You are asking yourself what elements of the essay or speech would cause an audience to believe that the argument is (or is not) logical and supported by appropriate evidence.

To evaluate whether the evidence is appropriate, apply the STAR criteria: how S ufficient, T ypical; A ccurate, and R elevant is the evidence?

Recognizing a Manipulative Appeal

Diagramming the argument – identifying the main claim and the main supporting points or premises – can help you determine if an appeal to logos is manipulative. Write out the main claim or conclusion. Then identify the supporting claims or premises. Are the premises true? Does the conclusion follow logically from the premises? Is there sufficient, typical, accurate, and relevant evidence to support the reasoning? Is the speaker or author attempting to divert your attention from the real issues? These are some of the elements you might consider while evaluating an argument for the use of logos.

Pay particular attention to numbers, statistics, findings, and quotes used to support an argument. Be critical of the source and do your own investigation of the “facts.” Maybe you’ve heard or read that half of all marriages in America will end in divorce. It is so often discussed that we assume it must be true. Careful research will show that the original marriage study was flawed, and divorce rates in America have steadily declined since 1985 (Peck, 1993). If there is no scientific evidence, why do we continue to believe it? Part of the reason might be that it supports the commonly held idea of the dissolution of the American family.

Deductive Logic

An argument using deductive logic is one that works from the top to the bottom. It begins with what is known as a "major premise," adds a "minor premise," and attempts to reach a conclusion. A major premise is a statement that comments about a large group, a minor premise refers to a single member, and the conclusion attempts to prove that because this single member is a part of the larger group, it must, therefore, also have the trait named in the major premise.

For example:

Now, if it is true that men are tall, and that Bob is a man, then we can safely infer that Bob must be tall. However, beware the logical fallacy. Though it may be true that in certain cultures men are, on average, taller than women, certainly this is not always the case. Being that our major premise is not altogether true, we can now say that this argument is flawed. Further, we might ask what our definition of "tall" is. Tall is different if we are talking about the average population, different for basketball players. Also, what is a man? Are transgendered individuals included? We see that the problem becomes far more complex the more we look into it.

Inductive Logic

While some would argue that a deductive argument works from the top down, toward a conclusion, and that an inductive argument works from the bottom up. This is mildly misleading. What is meant by this is that an inductive logical argument begins with a firm affirmation of truth, a conclusive statement. By getting the audience to agree with this statement, the argument moves to the next "logical" step. It proceeds in this manner until the argument has led you from one seemingly reasonable conclusion to another that you may not have originally agreed with. Take the following as an example. (Move through the argument slowly, making sure you understand and agree with each step in the process -- and please forgive the religious content, you'll come to see it is irrelevant anyway).

The human soul is inherently free. This is its very nature. We are confined to our mortal, earthly bodies, but our souls must be kept free, or the nature of the soul is entirely negated. If one chooses to believe in a soul, they can only believe that it embraces this (vague idea of) freedom.

At conception, a child is given a soul. Some may argue that that happens after birth, but if those very same persons are pro-life, they confuse their arguments. Thus, if someone is pro-life, and believes in a soul, they must believe in the freedom of that soul, and also accept that the soul is granted upon conception.

A soul cannot die. By the same means by which it is free over the body, a soul claims immortality while the body decomposes and is ended. To deny that a soul is immortal is again to deny the very essence of a soul. Thus, if someone is pro-life, and believes in a soul, they must believe in the freedom of that soul, the immortality of the soul, and also accept that the soul is granted upon conception.

A soul cannot be born. It is immortal and cannot die, it is not earthly, it forever exists, and cannot be born. There are tales in Greek mythology of Athena’s birth, yet she is born from her father’s head a fully decorated woman. She was not born. She existed previously, as Milton writes the Son in Paradise Lost. If one accepts the Bible’s teachings, there can be no reincarnation, no other form of birth, or rebirth. Thus, if someone is pro-life, and believes in a soul, and does not accept reincarnation, they must believe in the freedom of that soul, the immortality of the soul that is always and forever (which cannot be born and cannot die), and also accept that the soul is granted upon conception.

A soul being always an essence, and not being able to be reincarnated, can only exist outside of the body, somewhere, until the act of conception occurs. That soul must then be placed in the body that was forever intended to receive it, as it belongs nowhere else. The soul is fated to that one body. Thus, if someone is pro-life, and believes in a soul, and does not accept reincarnation, namely a practicing Catholic, they must also believe in the freedom of the soul, and in the concept of fate. Fate, however, completely opposes the idea of freedom. One cannot then believe in a soul, for it immediately enforces a belief in fate which directly negates the belief in the soul. If our actions are written in a Divine plan, we are not free to make our own choices. Every action has been scripted.

Don't worry, it must be that you were meant to read this.

Here's a sample inductive argument by Ben Doberstein.

Having seen this, some might say that the argument defeats Catholicism from an atheist standpoint. Others might find that it argues for the secularization of religion. Still, there are ways in which it supports Catholicism at the same time.

Though the argument might seem as if it is disagreeing with the Catholic religion, and some would agree that it is, we must always be looking for the logical fallacy. Upon closer inspection, you may notice that all this argument truly does, in one reading of the text, is to explain the complexity of God through the mind of a human. Catholicism has argued since the beginning that God is impossible to fully explain using the conceptions of man. In that way, this argument only supports that conclusion.

Be aware that there will be logic fallacies hidden in almost every argument. If there is more than one side to an argument, such as in religious or political debates, it is most likely because the argument is impossible to prove. Hence, there is a logical fallacy in the argument.

Fallacies that misuse appeals to logos or attempt to manipulate the logic of an argument are discussed below.

Fallacies that Misuse an Appeal to Logos

Hasty generalization: jumping to conclusions based upon an unrepresentative sample or insufficient evidence.

Example: “10 of the last 14 National Spelling Bee Champions have been Indian American. Indian Americans must all be great spellers!”

Appeal to ignorance—true believer’s form: arguing along the lines that if an opponent can’t prove something isn’t the case, then it is reasonable to believe that it is the case; transfers the burden of proof away from the person making the claim (the proponent).

Example: “You can’t prove that extraterrestrials haven’t visited earth, so it is reasonable to believe that they have visited earth.”

Appeal to ignorance—skeptic’s form: confusing absence of evidence with evidence of absence; assumes that if you cannot now prove something exists, then it is shown that it doesn’t exist.

Example: “There’s no proof that starting classes later in the day will improve the performance of our high school students; therefore, this change in schedule will not work.”

Begging the question: circular argument because the premise is the same as the claim that you are trying to prove.

Example: “This legislation is sinful because it is the wrong thing to do.”

False dilemma: misuse of the either/or argument; presenting only two options when other choices exist

Example: “Either we pass this ordinance or there will be rioting in the streets.”

Post hoc ergo propter hoc: Latin phrase meaning “after this, therefore because of this”; confuses correlation with causation by concluding that an event preceding a second event must be the cause of that second event.

Example: “My child was diagnosed with autism after receiving vaccinations. That is proof that vaccines are to blame.”

Non-sequitur: Latin for “does not follow”; the conclusion cannot be inferred from the premises because there is a break in the logical connection between a claim and the premises that are meant to support it, either because a premise is untrue (or missing) or because the relationship between premises does not support the deduction stated in the claim.

Example (untrue premise): “If she is a Radford student, she is a member of a sorority. She is a Radford student. Therefore she is a member of a sorority.”

Smoke screen : avoiding the real issue or a tough question by introducing an unrelated topic as a distraction; sometimes called a red herring .

Example: “My opponent says I am weak on crime, but I have been one of the most reliable participants in city council meetings.”

4603295958_500d6510d4_z.jpg

Image by Mark Klotz on flickr CC BY-NC: Attribution-NonCommercial

The red herring is as much a debate tactic as it is a logical fallacy. It is a fallacy of distraction and is committed when a listener attempts to divert an arguer from his argument by introducing another topic. This can be one of the most frustrating, and effective, fallacies to observe.The fallacy gets its name from fox hunting, specifically from the practice of using smoked herrings, which are red, to distract hounds from the scent of their quarry. Just as a hound may be prevented from catching a fox by distracting it with a red herring, so an arguer may be prevented from proving his point by distracting him with a tangential issue.

Straw man: pretending to criticize an opponent’s position but actually misrepresenting his or her view as simpler and/or more extreme than it is and therefore easier to refute than the original or actual position; unfairly undermines credibility of claim if not source of claim.

Example: “Senator Smith says we should cut back the Defense budget. His position is that we should let down our defenses and just trust our enemies not to attack us!”

Evaluating an Appeal to Pathos

People may be uninterested in an issue unless they can find a personal connection to it, so a communicator may try to connect to her audience by evoking emotions or by suggesting that author and audience share attitudes, beliefs, and values—in other words, by making an appeal to pathos. Even in formal writing, such as academic books or journals, an author often will try to present an issue in such a way as to connect to the feelings or attitudes of his audience.

When you evaluate pathos, you are asking whether a speech or essay arouses the audience’s interest and sympathy. You are looking for the elements of the essay or speech that might cause the audience to feel (or not feel) an emotional connection to the content.

An author may use an audience’s attitudes, beliefs, or values as a kind of foundation for his argument—a layer that the writer knows is already in place at the outset of the argument. So one of the questions you can ask yourself as you evaluate an author’s use of pathos is whether there are points at which the writer or speaker makes statements assuming that the audience shares his feelings or attitudes. For example, in an argument about the First Amendment, does the author seem to take it for granted that the audience is religious?

Recognizing a Manipulative Appeal to Pathos

Up to a certain point, an appeal to pathos can be a legitimate part of an argument. For example, a writer or speaker may begin with an anecdote showing the effect of a law on an individual. This anecdote will be a means of the author gaining an audience’s attention for an argument in which they use evidence and reason to present their full case as to why the law should/should not be repealed or amended. In such a context, engaging the emotions, values, or beliefs of the audience is a legitimate tool, the effective use of which should lead you to give the author high marks.

An appropriate appeal to pathos is different than trying to unfairly play upon the audience’s feelings and emotions through fallacious, misleading, or excessively emotional appeals. Such a manipulative use of pathos may alienate the audience or cause them to “tune out”. An example would be the American Society for the Prevention of Cruelty to Animals (ASPCA) commercials featuring the song “ In the Arms on an Angel ” and footage of abused animals. Even Sarah McLachlan, the singer and spokesperson featured in the commercials, admits that she changes the channel because they are too depressing (Brekke, 2014).

Even if an appeal to pathos is not manipulative, such an appeal should complement rather than replace reason and evidence-based argument. In addition to making use of pathos, authors must establish their credibility (ethos) and must supply reasons and evidence (logos) in support of their position. An author who essentially replaces logos and ethos with pathos alone should be given low marks.

See below for the most common fallacies that misuse appeals to pathos.

Fallacies that Misuse an Appeal to Pathos

Appeal to fear: using scare tactics; emphasizing threats or exaggerating possible dangers.

Example: “Without this additional insurance, you could find yourself broke and homeless.”

Appeal to guilt and appeal to pity : trying to evoke an emotional reaction that will cause the audience to behave sympathetically even if it means disregarding the issue at hand.

Example: “I know I missed assignments, but if you fail me, I will lose my financial aid and have to drop out.”

Appeal to popularity (bandwagon): urging tthe audience to follow a course of action because “everyone does it.”

Example: “Nine out of ten shoppers have switched to Blindingly-Bright-Smile Toothpaste.”

Slippery Slope: making an unsupported or inadequately supported claim that “One thing inevitably leads to another.” This may be considered a fallacy of logos as well as pathos but is placed in this section because it often is used to evoke the emotion of fear.

Example: “We can’t legalize marijuana; if we do, then the next thing you know people will be strung out on heroin.”

Appeal to the people: also called stirring symbols fallacy; the communicator distracts the readers or listeners with symbols that are very meaningful to them, with strong associations or connotations.

Example: This fallacy is referred to in the sentence “That politician always wraps himself in the flag.”

Appeal to tradition: people have done it a certain way for a long time; assumes that what has been customary in the past is correct and proper.

Example: “A boy always serves as student-body president; a girl always serves as secretary.”

Loaded-Language and other emotionally charged uses of language: using slanted or biased language, including Goodness terms, devil terms, euphemisms, and dysphemisms.

Example: In the sentence “Cutting access to food stamps would encourage personal responsibility,” the "goodness" term is “personal responsibility.” It might seem as if it would be hard to argue against “personal responsibility” or related "goodness" terms such as “independence” and “self-reliance.” However, it would require a definition of “personal responsibility,” combined with evidence from studies of people’s behavior in the face of food stamp or other benefit reductions, to argue that cutting access to food stamps would lead to the intended results.

Fallacies can crop up whenever definitions, inferences, and facts are at issue. Once we become familiar with fallacies we may start to see them everywhere. That can be good and bad. Since persuasion is ever-present, it is good to be on guard against various hidden persuaders. But whether a persuasive strategy is considered fallacious may be dependent on context. For example, we expect advertisements, political speeches, and editorials on public policy or ethical issues to try to sway us emotionally.

However, as a writer of logical argument, your task is to evaluate your draft in order to identify and eliminate inappropriate logical fallacies, which often try to argue through emotional means, personal attack, or inappropriate evidence and conclusions. Your purpose, as a writer of logical argument, is to get your reader to see the value in what you’re asserting, to get that person to say “I understand and accept the validity of your point of view,” even though he may still not agree.

Identifying Hasty Generalizations

A generalization is a reasonably true statement based on statistically valid data. A hasty generalization is a statement that is true in general but may not be true in any particular case. A generalization becomes a hasty generalization when the statement is assumed to be true about an individual or when the generalization is statistically invalid. Hasty generalizations are one of the most common logical fallacies.

Decide whether the following statements are generalizations or hasty generalizations:

A. Dogs developed from wolves.

B. You’ll be a victim of a crime if you are out between 1 a.m. and 3 a.m.

C. Crime happens more often in cities than in suburbs.

D. Women are more neurotic than men (according to a fired Google employee manifesto).

E. Pit bulls are killers.

F. Billionaires are greedy.

Identifying Logical Fallacies and Appeals

Individually or in groups, identify the logical fallacies (by name) or appeals in the following statements.

1. Pilots claim to have seen unidentified flying objects (spacecraft from other planets). Pilots are trained in observation and are reliable, so UFOs must exist.

2. The universe has all the properties to support life; therefore, it was designed specifically to support life.

3. What are skeptics of alternative medicines afraid of?

4. There is no evidence to show ghosts exist, so ghosts do not exist.

5. Mammals live on land. Whales are mammals. Therefore, whales must live on land.

6. The number of transistors in a dense integrated circuit doubles approximately every two years.

7. More people in the world smoke than in the past. The rate of people dying from lung cancer is declining. Smoking does not cause lung cancer.

8. Drinking alcohol increases one’s risk for breast cancer. Katie drinks four glasses of wine per week. She will develop breast cancer.

9. Computers are the brains of machines, so people should not need much sleep for their brains to work properly.

10. The earliest remains of Homo erectus are in Africa and Asia, so the species originated in one of those places.

11. The extinction of large mammals will inevitably lead to the extinction of humans.

12. Humans are destroying Earth, so we should colonize Mars so we can survive.

13. We don’t know how placebos work, so they must not work.

Logical Fallacies Review

The following video, while relatively lengthy, clearly explains many common logical fallacies such as hasty generalization, slippery slope, and more. As such, it provides a good review of the fallacies that you should be identifying and editing out of your logical argument essay drafts.

Video: Logical Fallacies by US Represented. All Rights Reserved. Standard YouTube license.

Contributors:

  • Adapted from College Writing , authored by Susan Oaks, provided by Empire State College, SUNY OER Services. License : CC BY-NC-SA:

This page last updated on June 5, 2020.

Banner

Critical Thinking - Writing Lab Tips and Strategies: Logical Fallacies

Logical fallacies.

Fallacies are fake or deceptive arguments, arguments that may sound good but prove nothing.

Ad Hominem Argumen t :  Attacking the person instead of the argument.

Appeal to Closure :  The argument that the issue must be decided so that those involved can have "closure."

Appeal to Heaven : Arguing that one's position or action is right because God said so.  As Christians, we believe God has revealed his will through Scripture, but we can still fall into this fallacy if we attempt to justify ourselves apart from what the Bible says.  Even if we are being consistent with Scripture, we may still be accused of this fallacy.

Appeal to Pity : Urging an audience to “root for the underdog” regardless of the issues at hand.

Appeal to Tradition :  It's always been this way, it should continue to be this way.

Argument from Consequences : The fallacy of arguing that something cannot be true because if it were the consequences would be unacceptable.

Argument from Ignorance:  The fallacy that since we don’t know whether a claim is true or false, it must be false (or that it must be true).

 Argument from Inertia:  The argument to continue on as before because changing would be admitting that one is wrong and that one had sacrificed needlessly.

Argument from Motives:   The argument that someone must be wrong because their motives are wrong.  Also, the reverse: someone is right because their motives are right.

Argumentum ad Baculam:   Attempting to persuade through threats.  Also applies to indirect forms of threat.

Argumentum ex Silentio:   The fallacy that if sources remain silent or say nothing about a given subject or question this in itself proves something about the truth of the matter.

Bandwagon:   The fallacy of arguing that because "everyone" supposedly thinks or does something, it must be right.  

Begging the Question : Falsely arguing that something is true by repeating the same statement in different words.

Big Lie Technique:   Repeating a lie, slogan or deceptive half-truth over and over (particularly in the media) until people believe it without further proof or evidence.

Blind Loyalty:   Arguing something is right solely because a respected leader or source says it is right. 

Blood is Thicker than Water:    Automatically regarding something as true because one is related to (or knows and likes, or is on the same team as) the individual involved. 

Bribery:  Persuading with gifts instead of logic.

The Complex Question : Demanding a direct answer to a question containing acceptable and unacceptable parts.  Example: "Yes or no: Have you stopped beating your wife yet?"  "I never beat my--"  "Just answer me: Yes or no?"

Diminished Responsibility : The argument that one is less responsible for an action because one's judgment was altered.  Example:  "I was high, so I shouldn't be fined for speeding; it wasn't my fault."

Either-Or Reasoning:   Falsely offering only two possible alternatives even though a broad range of possible alternatives are available.

”E" for Effort:  Arguing that something must be right, valuable, or worthy of credit simply because someone has put so much sincere good-faith effort or even sacrifice and bloodshed into it.

Equivocation : Deliberately failing to define one's terms, or deliberately using words in a different sense than the one the audience will understand.

Essentializing : A fallacy that proposes a person or thing “is what it is and that’s all that it is,” and at its core will always be what it is right now (E.g., "All ex-cons are criminals, and will still be criminals even if they live to be 100."). Also refers to the fallacy of arguing that something is a certain way "by nature," an empty claim that no amount of proof can refute.

False Analogy : Incorrectly comparing one thing to another in order to draw a false conclusion. 

Finish the Job:   Arguing that an action or standpoint may not be questioned or discussed because there is "a job to be done," falsely assuming all "jobs" are never to be questioned. 

Guilt by Association:  Trying to refute someone's arguments or actions by evoking the negative ethos of those with whom one associates.

The Half Truth  (also Card Stacking, Incomplete Information).Telling the truth but deliberately omitting important key details in order to falsify the larger picture and support a false conclusion.

I Wish I Had a Magic Wand:   Regretfully (and falsely) proclaiming oneself powerless to change a bad or objectionable situation because there is no alternative.

Just in Case : Basing one's argument on a far-fetched or imaginary worst-case scenario rather than on reality. Plays on fear rather than reason.

Lying with Statistics : Using true figures and numbers to “prove” unrelated claims.

MYOB   (Mind Your Own Business) Arbitrarily prohibiting any discussion of one's own standpoints or behavior, no matter how absurd, dangerous, evil or offensive, by drawing a phony curtain of privacy around oneself and one's actions. 

Name-Calling:   Arguing that, simply because of who someone is, any and all arguments, disagreements or objections against his or her standpoint are automatically  racist, sexist, anti-Semitic, bigoted, discriminatory or hateful. 

Non Sequitur : Offering reasons or conclusions that have no logical connection to the argument at hand.

Overgeneralization:   Incorrectly applying one or two examples to all cases.

The Paralysis of Analysis : Arguing that since  all  data is never in, no legitimate decision can ever be made and any action should always be delayed until forced by circumstances. 

Playing on Emotions : Ignoring facts and calling on emotion alone.

Political Correctness   ("PC"): Proposing that the nature of a thing or situation can be changed simply by changing its name. 

Post Hoc Argument : Arguing that because something comes at the same time or just after something else, the first thing is caused by the second.

Red Herring : An irrelevant distraction, attempting to mislead an audience by bringing up an unrelated, but usually emotionally loaded issue.

Reductionism : Deceiving an audience by giving simple answers or slogans in response to complex questions, especially when appealing to less educated or unsophisticated audiences.

Reifying : The fallacy of treating imaginary categories as actual, material "things."

Sending the Wrong Message : Attacking a given statement or action, no matter how true, correct or necessary, because it will "send the wrong message." In effect, those who uses this fallacy are publicly confessing to fraud and admitting that the truth will destroy the fragile web of illusion that has been created by their lies.

Shifting the Burden of Proof: Challenging opponents to disprove a claim, rather than asking the person making the claim to defend his/her own argument.

Slippery Slope : The common fallacy that "one thing inevitably leads to another."

Snow Job :   "Proving” a claim by overwhelming an audience with mountains of irrelevant facts, numbers, documents, graphs and statistics that they cannot be expected to understand.

Straw Man : Setting up a phony version of an opponent's argument, and then proceeding to knock it down with a wave of the hand.

Taboo : Unilaterally declaring certain arguments, standpoints or actions to be not open to discussion.

Testimonial : When a standpoint or product is supported by a well-known or respected figure who is not an expert and who was probably well paid for the endorsement.

They're Not Like Us :  Arbitrarily disregarding a fact, argument, or objection because those involved "are not like us," or "don't think like us."

TINA  (There Is No Alternative): Squashing critical thought by announcing that there is no realistic alternative to a given standpoint, status or action, ruling any and all other options irrelevant and any further discussion is simply a waste of time.

Transfer : Falsely associating a famous person or thing with an unrelated standpoint.

Tu Quoque:  Defending a shaky or false standpoint or excusing one's own bad action by pointing out that one's opponent's acts or personal character are also open to question, or even worse.

We Have to Do  Something : Arguing that in moments of crisis one must do something,  anything , at once, even if it is an overreaction, is totally ineffective or makes the situation worse, rather than "just sitting there doing nothing." 

Where there’s smoke, there’s fire : Quickly drawing a conclusion and/or taking action without sufficient evidence.

For more in-depth discussion of these fallacies, refer to http://utminers.utep.edu/omwilliamson/ENGL1311/fallacies.htm

Subject Guide

Profile Photo

I'm trying to think critically, but I'm a frog

  • << Previous: Home
  • Last Updated: May 17, 2023 3:05 PM
  • URL: https://libguides.grace.edu/CriticalThinking

Passion doesn’t always come easily. Discover your inner drive and find your true purpose in life.

From learning how to be your best self to navigating life’s everyday challenges.

Discover peace within today’s chaos. Take a moment to notice what’s happening now.

Gain inspiration from the lives of celebrities. Explore their stories for motivation and insight into achieving your dreams.

Where ordinary people become extraordinary, inspiring us all to make a difference.

Take a break with the most inspirational movies, TV shows, and books we have come across.

From being a better partner to interacting with a coworker, learn how to deepen your connections.

Take a look at the latest diet and exercise trends coming out. So while you're working hard, you're also working smart.

Sleep may be the most powerful tool in our well-being arsenal. So why is it so difficult?

Challenges can stem from distractions, lack of focus, or unclear goals. These strategies can help overcome daily obstacles.

Unlocking your creativity can help every aspect of your life, from innovation to problem-solving to personal growth.

How do you view wealth? Learn new insights, tools and strategies for a better relationship with your money.

9 Logical Fallacies That You Need to Know To Master Critical Thinking

9 Logical Fallacies That You Need to Know To Master Critical Thinking

When you learn about logic, language becomes a game you can win..

William James, who was known as the grandfather of psychology, once said: “A great many people think they are thinking when they are merely rearranging their prejudices.” All of us think, every day. But there’s a difference between thinking for thinking’s sake, and thinking in a critical way. Deliberate, controlled, and reasonable thinking is rare.

There are multiple factors that are impairing people’s ability to think critically, from technology to changes in education. Some experts have speculated we’re approaching a crisis of critical thinking , with many students graduating “without the ability to construct a cohesive argument or identify a logical fallacy.”

RELATED: How to Tell if ‘Political Correctness’ Is Hurting Your Mental Health

That's a worrying trend, as critical thinking isn’t only an academic skill, but essential to living a high-functioning life. It’s the process by which to arrive at logical conclusions. And in through that process, logical fallacies are a significant hazard.

This article will explore logical fallacies in order to equip you with the knowledge on how to think in skillful ways, for the biggest benefits. As a result, you'll be able to detect deception of flawed logic, in others, and yourself. And you'll be equipped to think proper thoughts, rather than simply rearrange prejudices.

What Is a Logical Fallacy?

The study of logic originates back to the Greek philosopher Aristotle (384–322 b.c.e), who started to systematically identify and list logical fallacies. The origin of logic is linked to the Greek logos , which translates to language, reason, or discourse. Logical fallacies are errors of reason that invalidate an argument. The use of logical fallacies changes depending on a person’s intention. Although for many, they’re unintentional, others may deliberately use logical fallacies as a type of manipulative behavior .

Detecting logical fallacies is crucial to improve your level of critical thinking, to avoid deceit, and to spot poor reasoning; within yourself and others. The influential German philosopher Immanuel Kant once said; “All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.”

RELATED: Fundamental Attribution Error: Definition & Examples

Throughout history, the world’s greatest thinkers have promoted the value of reasoning. Away from academia, reason is the ability to logically process information, and arrive at an accurate conclusion, in the quest for truth. Striving to be more reasonable or calm under pressure is a virtuous act. It’s a noble pursuit, one which in its nature will inspire your personal development, and allow you to become the best version of yourself.

Why Critical Thinking Is Important

It seems like humanity has never been so polarized, separated into different camps and stances; Democrats vs. Liberals, vegans vs. meat eaters, vaccinated vs. unvaccinated, pro-life vs. pro-choice. There’s nothing inherently wrong with thinking critically, and taking a stand. However, what is unusual is the tendency for people to lean into one extreme or the other, neglecting to explore gray areas or complexity.

Many of the positions people take are chosen for them. It takes a lot of effort to research a point of view. And even then, we’re faced with the challenge of information overload, fake news, conspiracy, and even credible news which is dismissed as conspiracy. Far from academic debates or politicians facing off during leadership races, the ability to share respectful dialogue is an essential part of understanding our place in the world, and maintaining human relationships.

The hot topics facing humanity aren’t going to be resolved by reactivity or over-emotionality . There should be room for all sorts of emotions to surface; it’s understandable to feel anger, grief, anxiety, etc, faced with global events. But critical thinking asks for a more reasoned, calm consideration, not getting completely carried away with emotions, but appealing to higher judgment.

Examples of When to Use Critical Thinking

It’s not always clear why critical thinking is so valuable. Isn’t it only useful for education, philosophy, science, or politics? Not quite. When applied appropriately, logic has a universal appeal in life. Examples include:

  • Problem-solving : “The problem is not that there are problems,” wrote psychiatrist Theodore Isaac Rubin, “the problem is expecting otherwise, and thinking that having problems is a problem.” Life is full of problems. Fortunately, that means life is full of opportunities to problem solve. Critical thinking is an essential problem-solving skill, from managing your time to organizing your finances.
  • Making optimal decisions : the more logical you are, and the less you fall into logical fallacies, the better your decision-making becomes . Decisions are the steps towards your goals, each decision making you closer to, or away from, what you really desire.
  • Understanding complex subjects : with attention spans reducing due to social media and technology, it’s becoming rare to take time to attempt to understand complex topics, away from repeating what others have said. Whether through self-study or to comprehend global events, critical thinking is essential to understand complexity.
  • Improving relationships : adding a dose of logic to your interactions will allow you to make better choices in relationships. Many “messy” forms of communication, from guilt-tripping to passive aggression, are illogical. By tapping into a more balanced point of view, you’ll better overcome conflict, argue your point (when necessary), or explain the way you feel.

The Most Common Logical Fallacies

When you begin to explore logical fallacies, language becomes a game. There’s a sense of having a cheat sheet in communication, understanding the underlying dynamics at play. Of course, it’s not as straightforward as a mechanical understanding — emotional intelligence, and non-verbal body language has a role to play, too. We’re humans, not computers. But gaining mastery of logic puts you ahead of the majority of people, and helps you avoid cognitive bias.

What’s more, most people fall into logical fallacies without being aware. Once you can detect these mechanisms, within yourself and with others, you’ll have an upper hand in many key areas of life, not least in a professional setting, or in any place you need to persuade or argue a point. The list is ever-growing and vast, but below are the most common logical fallacies to get the ball rolling:

1. Ad Hominem

Originating from a Latin phrase meaning “to the person,” ad hominem is an attack on the person, not the argument. This has a twofold impact — it deflects attention away from the validity of the argument, and second, it can provoke the person to enter a defensive mindset. If you’re aware of this fallacy, it can keep you from taking the bait, and instead keeping the focus on the argument.

Perhaps the most popular example of this in recent times is the viral interview between Jordan Peterson and Cathy Newman. Love him or hate him, Peterson is an embodiment of logic, sidestepping Newman’s ad hominem attacks and fallacies in a calm and controlled manner. 

2. Red Herring

You might have heard of this phrase in the context of fiction: a red herring is an irrelevant piece of information thrown into the mix, in order to distract from other relevant details, commonly used in detective stories. In a political context, you might see a politician respond to criticism by talking about something positive they’ve done. For example, when asked why unemployment is so high, they may say “we’ve made a lot of effort to improve working conditions in certain areas.”

A popular type of red herring in modern discourse is "what aboutism," a form of counter-accusation. If the person mentioning unemployment is a fellow politician, the same politician may say: “what about unemployment rates when your party was in charge?”

3. Tu Quoque Fallacy

Closely related to the above, and in some ways, a mixture of the ad hominem and a red herring, is the tu quoque fallacy (pronounced tu-KWO-kway and originating from the Latin “you too”). This is a counter-accusation that accuses someone of hypocrisy. Rather than acknowledging what's been said, someone responds with a direct allegation. For example, if you’re in an argument and your partner raises their voice, you may bring that to their attention, only for them to say: “you raise your voice all the time!”.

4. Straw Man

The straw man logical fallacy is everywhere, especially in dialogue on hot-topic issues, because it's effective in shutting down someone else’s perspective. The person runs with someone’s point, exaggerates it, then attacks the exaggerated version — the straw man — seemingly in an appropriate way. For example, when your partner asks if you could do the washing up, you might respond: “are you saying I don’t support you around the house? That’s unfair.”

On the global stage, one of the big straw man arguments in recent times is the rhetoric of the anti-vaxxer, applied to resistance to mandated vaccines, social distancing, or lockdowns. The simplified term is a way of positioning someone as extreme, even if raising valid points, or looking to open dialogue about the repercussions of certain political choices, made without the option for the population to have their say.

5. Appeal to Authority

If someone in a position of authority says something is true, it must be true. This type of logical fallacy is ingrained in the psyche in childhood, where your parents' (or adults around you) word was final. Society is moving increasingly in this direction, especially in the fields of science. But that doesn’t come without risk, as even experts are known not to get things right. 

In addition, many positions of authority aren’t always acting in pursuit of honesty or truth, if other factors (such as financial donations) have influence. While appeals to authority used to gravitate around religious leaders, a 2022 study found that, when linked with scientists, untrue statements are more likely to be believed, in what researchers call the Einstein effect .

6. False Dichotomy

Also known as the false dilemma, this logical fallacy presents limited options in certain scenarios in a way that is inaccurate. It’s closely linked to black-or-white thinking or all-or-nothing thinking, presenting two extremes without options in between. This is perhaps one of the most invasive logical fallacies in navigating life’s demands. For example, you either go to the gym or become unhealthy.

These limitations require a dose of psychological flexibility and creative thinking to overcome. They require exploring other alternatives. In the example above, that would mean looking at other ways to become healthy and exercise, such as running outdoors or going swimming.

7. Slippery Slope Fallacy

Similar to the straw man fallacy, the slippery slope is a way of taking an issue to a hypothetical extreme and then dismissing it based on what could happen. The potential of one thing leading to another, and the repercussions of that chain of events, may cause the original issue to be overlooked. For example, if you fail to set a boundary in one situation, you’ll forever be stuck in accepting certain behaviors.

The issue with this fallacy is that a valid process of critical thinking is to look at what decisions can lead to in the future. Rather than dismiss outright, however, it pays to make reasoned decisions, avoid jumping to conclusions, and see how things unfold over time.

8. Sunk Cost Fallacy

This is the logical fallacy that, when having already invested in something, you continue to invest in order to get return on your sunk costs. Although using gambling terminology (such as chasing losses on roulette) the sunk cost can apply to any area of life. The investment itself doesn’t have to be financial. For example, investing lots of time and energy into a creative project, or a relationship.

The sunk cost fallacy causes people to overlook a true and accurate analysis of the situation in the present moment, instead choosing to continue because of past decisions.

9. Hasty Generalisation

Also known as an over-generalization or faulty generalization, this logical fallacy makes general claims based on little evidence. Before writing this article, I went to a new gym, where my toiletry bag was stolen. You could argue it’s bad luck for something like that to happen on your first visit. If I decide that the gym isn’t safe, and make a hasty generalization, I may end up not going again. But what if the rate of theft in this gym was below the average in the city, and I was just unlucky? What if it wasn’t stolen, but someone absent-mindedly put it in their bag?

The opposite of a hasty generalization is to find the appropriate context for events. A logical conclusion, on the other hand, takes time. It’s reasonable, doesn’t jump in, and collects as much data as possible. If I go to the same gym, and something else is stolen, and I then see in Google reviews that others have had the same, it’d be logical for me to conclude there’s a high rate of theft.

How to Detect and Overcome Logical Fallacies

Both logic and critical thinking can be improved with practice. The knowledge of the nature of logical fallacies, and the above examples, will get you started. Deciphering when certain fallacies are active in real time is part of applied learning. Be conscious of applying the same level of rigor to your own level of reason as you do others.

There are a few components to detect and overcome logical fallacies. The first is self-awareness. As mentioned above, we’re humans, not machines. In situations where the stakes are high, we’re usually driven by factors other than logic, ulterior motives, or strong emotions that run the show. How often, when angry or triggered, do you say or act in ways you later regret?

Emotional regulation is useful in being calm enough to engage in critical thinking. But at times, logic isn’t the most skillful. For example, in conflict with a loved one, it’s more important to attempt to have compassion and understanding than to be the “most logical.” Sometimes, there are factors outside of reason that influence us, matters of the heart that can’t be captured, defined, or deconstructed by the mind.

Knowing how to apply logic, and when, is a vital skill. Through practice, over time, you’ll cultivate an even greater virtue — wisdom. A precious commodity in short supply, if you’re able to achieve wisdom and reason, the world is your oyster, a positive slippery slope to supercharge your growth.

KEEP READING

What is cognitive bias how to wave goodbye to mental distortions, hot stories, man finds out his ex-girlfriend wants to put their daughter up for adoption - flies across the world to stop it, interabled couple gets married despite naysayers, proving that love is for everyone, man lives on street for 3 years waiting for his mother - then a stranger who kept passing by him, took him in, woman can’t afford rent - so she moves in with her 94-year-old nonna, woman poses a question to dads online - video "backfired" for all the wrong reasons, dan lok | my hero is my teacher, family rejects $100m offer for their ranch — they saved their community instead.

Family Rejects $100M and Preserves Honey Creek State Area

In a world where financial gain often trumps environmental conservation, one Texas family made an extraordinary decision that prioritizes the greater good.

The Urbanczyk family turned down a potential $100 million profit to preserve their 245-acre ranch in Hill Country, transforming it into a public park for future generations to enjoy. This inspiring story underscores the importance of protecting our natural heritage and the selfless acts that make it possible.

A Bold Decision For The Greater Good

Honey Creek Natural Area | Ronnie and Terry Urbanczyk pose for camera

Dave Sims Media/The Nature Conservancy | www.savehoneycreek.com

Ronnie and Terry Urbanczyk, who purchased their 245-acre ranch near the Honey Creek State Natural Area three decades ago, faced a significant choice.

Over the years, they expanded their property to 750 acres and considered capitalizing on the booming Hill Country population by developing housing on their land. Such a move could have secured a $125 million inheritance for their children. However, their neighbors and local conservationists expressed concerns about the potential environmental impact, particularly on Honey Creek's fragile ecosystem and pristine waters.

Ronnie recalled the moment they involved their family in the decision-making process: "We brought them into the equation, and said, ‘Hey, what do y’all think?’ Because it was a huge financial ask of them also." To their delight, their children unanimously supported the idea of preserving the land as a park. “Dad, if it could be a park we could drive by and see the rest of our lives, and our grandkids' lives, let’s make it a park,” they said.

The Birth Of A Public Park

Trees and water

ONE SWEET CONSERVATION DEAL Honey Creek State Natural Area in Central Texas. © Dave Sims Media

After years of planning, Texas Parks and Wildlife announced in June 2023 that they would purchase the Urbanczyks' 515-acre ranch for $25 million. This transaction would ensure the land's preservation, safeguarding nearly 5,000 acres of habitat alongside the adjacent Guadalupe River State Park.

Rodney Franklin, Texas State Parks Director, emphasized the significance of this acquisition: “Together with the adjacent Guadalupe River State Park, these protected lands encompass nearly 5,000 acres of habitat that sustain plants and wildlife, benefit water quality, and provide opportunities for people to spend time in nature.”

Terry Urbanczyk expressed her surprise at the possibility of creating a public park: “We were not aware that making it a park would be a possibility unless you just donate the land, which we couldn’t do.” The decision was a family affair, with Ronnie consulting his nine grandchildren, whom he fondly calls his “board of directors.” Their enthusiastic support, "Yes! Let’s do it!" reinforced the family's resolve.

The land, rich with pristine streams, cypress trees, and at-risk species such as golden-cheeked warblers and Comal blind salamanders, will now be accessible to the public. Texans will have the chance to create their own memories in this beautiful natural setting, just as the Urbanczyk family did.

A Reminder "You Can't Take It With You"

In a capitalist world obsessed with amassing fame and fortune, the Urbanczyks' decision to prioritize conservation over profit is a powerful reminder of the importance of protecting our natural resources. Ronnie, who owns a concrete business, reflected on the emotional significance of their choice: "And now the people in Texas are going to get to really enjoy it for the next thousand years," he said. The couple plans to retire overlooking the state’s natural area, comforted by the knowledge that it will remain unchanged.

Local experts will manage the ecosystem to prevent harmful construction, ensuring the area's ecological integrity for future generations. Annalisa Peace of the Greater Edwards Aquifer Alliance expressed gratitude for the Urbanczyks' foresight and generosity.

The family encourages other landowners to consider similar actions and seek assistance from organizations like the Nature Conservancy and state parks departments. Ronnie advises exploring creative solutions to protect sensitive ecosystems, noting the increased funding available for land preservation through initiatives like the Great American Outdoors Act of 2020 and recent state legislation.

The Urbanczyks' story is a testament to the profound impact individuals can have on environmental conservation. Their choice to forego substantial financial gain in favor of preserving natural beauty and biodiversity highlights a deep commitment to future generations. As Terry observed, their children understood the true value of their decision: “How much money does someone really need?”

Bride Gets a Shock At the ​Hair Salon on Wedding Day - Leaving Her In Tears

Man works at walmart deli - shocks the world when he qualifies for the olympics, bride is sad her mom will never meet her future husband - then falls in love with this man, man notices stranger's car was about to get a ticket - his response goes insanely viral, how tiffany haddish finally found the love she deserved, the disturbing and beautiful story behind danny trejo's salma hayek tattoo, the kardashian redemption - an uncensored documentary, how did betrayal connect jennifer aniston and selena gomez, subscribe to our newsletter, usher opens up on diddy's flavor camp, the great takedown of nickelodeon’s dan schneider - how even small voices have the power for impact, chris gardner beyond the pursuit of happyness: the work begins, 100 powerful motivational quotes to help you rise above, parents get trapped under car in tornado storm - their 9-year-old jumps into action.

9 Year Old Saves Parents Crushed In Car Amid Tornado Storm

In times of crisis, heroes often emerge in the most unexpected ways. Such is the story of Branson Baker, a 9-year-old boy from Dickson, Oklahoma, who demonstrated extraordinary bravery during a devastating EF-4 tornado.

His courageous actions saved his parents and serve as a powerful reminder of the resilience and strength found in even the youngest among us.

A Race Against Nature

Car trapped under tree

Lindy Baker/GoFundMe

On April 27, the Baker family found themselves in the path of a deadly tornado. Wayne and Lindy Baker, along with their son Branson, were racing to a friend's storm cellar for safety. As they drove, the tornado loomed ever closer, its destructive force visible within a mile or two. Wayne Baker described the harrowing moment:

"We could pretty much see this tornado within about a mile and two miles away from us. But as we turned, the tornado turned itself."

The situation turned dire when a tree, uprooted by the powerful winds, crashed onto their truck, trapping Wayne and Lindy inside. Despite his fear, Branson acted with remarkable quickness and presence of mind.

"I was really, really scared," the 9-year-old recounted to ABC News , but he knew he had to act.

"Please Don't Die" — One Last Hope For Help

Branson Baker's parents, Lindy and Wade pose for the camera.

Baker Family, KTVT via CNN

In a moment of pure courage, Branson managed to escape from the wrecked truck. His thoughts were with his parents as he ran for help, telling them, "Don't die," before sprinting over a mile to find assistance. Wayne Baker marveled at his son's bravery: "Branson sprung into action really quick. He's very courageous for a 9-year-old boy. Not many adults would have done what he did."

The urgency of the situation was palpable for Wayne's brother, Johnny Baker, who was on the phone with the family when the tree hit. "About that time, you start hearing some dinging on the glass, like, maybe hail and then boom. And the phone went silent," Johnny recalled. He and his wife rushed to the scene, with his wife calling 911. Branson, determined and undeterred, returned with help alongside the first responders.

Wayne Baker is now recovering from injuries to his back, neck, and arm, while Lindy remains in the hospital. Through it all, Wayne's pride in his son shines brightly. "You couldn't be more proud to be a father of a son that can accept a challenge that way," he said. "Shows that he would go above and beyond for anyone."

Triumph In The Face of Adversity

Branson Baker, 9, batters up!

The day after the tornado struck, Branson displayed his resilience and spirit in another way — on the baseball field. Despite the traumatic event, he hit a home run and turned a double play, dedicating his performance to his parents. His actions on and off the field are a testament to his strength and determination.

Branson’s story is a powerful reminder that heroes can come in all sizes and ages. His quick thinking and fearless actions in the face of a deadly tornado saved his parents and inspire us all. In moments of crisis, it is the courage and resilience of individuals like Branson that shine through, reminding us of the extraordinary capabilities within each of us, regardless of age.

For those wanting to help, the Bakers have a GoFundMe to help cover medical expenses for the family.

Copyright © 2024 Goalcast

Get stories worth sharing delivered to your inbox

35. Recognizing Logical Fallacies for Better Critical Thinking Podcast By  cover art

35. Recognizing Logical Fallacies for Better Critical Thinking

  • Dec 27 2023
  • Length: 27 mins

Failed to add items

Add to cart failed., add to wish list failed., remove from wishlist failed., adding to library failed, follow podcast failed, unfollow podcast failed.

35. Recognizing Logical Fallacies for Better Critical Thinking  By  cover art

What listeners say about 35. Recognizing Logical Fallacies for Better Critical Thinking

Reviews - please select the tabs below to change the source of reviews., audible.com reviews, amazon reviews, please sign in to report this content.

You'll still be able to report anonymously.

critical thinking and logical fallacies

  • Kindle Store
  • Kindle eBooks
  • Business & Money

Promotions apply when you purchase

These promotions will be applied to this item:

Some promotions may be combined; others are not eligible to be combined with other offers. For details, please see the Terms & Conditions associated with these promotions.

Buy for others

Buying and sending ebooks to others.

  • Select quantity
  • Buy and send eBooks
  • Recipients can read on any device

These ebooks can only be redeemed by recipients in the US. Redemption links and eBooks cannot be resold.

Kindle app logo image

Download the free Kindle app and start reading Kindle books instantly on your smartphone, tablet, or computer - no Kindle device required .

Read instantly on your browser with Kindle for Web.

Using your mobile phone camera - scan the code below and download the Kindle app.

QR code to download the Kindle App

Image Unavailable

The Art of Critical Thinking, Logic, &amp; Problem Solving: 15 Everyday Exercises to Enhance Your Cognitive Potential, Conquer Logical Fallacies, &amp; Polish ... Work &amp; Life (Emotional Resilience Book 3)

  • To view this video download Flash Player

Follow the author

Winston Meskill

The Art of Critical Thinking, Logic, & Problem Solving: 15 Everyday Exercises to Enhance Your Cognitive Potential, Conquer Logical Fallacies, & Polish ... Work & Life (Emotional Resilience Book 3) Kindle Edition

4 Free Bonuses With Your Purchase, To Enhance Your Critical Thinking Skills Even Further! If you’ve always wanted to sharpen your critical thinking skills, conquer logical fallacies, and make better decisions, but struggle to find effective methods, then keep reading…

Are you sick and tired of feeling overwhelmed by complex problems, unable to navigate through them with clarity and confidence?

Have you tried endless other solutions, only to find yourself right back where you started after a few weeks?

Do you finally want to say goodbye to sacrificing your time and energy on ineffective strategies, and discover something that truly works for you?

If so, then you’ve come to the right place.

You see, mastering the art of critical thinking, logic, and problem-solving doesn’t have to be difficult .

Even if you’ve tried other solutions that didn’t quite hit the mark.

In fact, it’s easier than you think.

Studies from reputable sources such as scientific journals and newspapers have demonstrated that incorporating specific exercises into your routine can significantly enhance your cognitive abilities and decision-making skills.

And another study revealed how conquering logical fallacies can lead to more successful outcomes in both your professional and personal life.

Which means you can unlock your full cognitive potential without sacrificing your time or energy.

Here’s just a tiny fraction of what you’ll discover in "The Art Of Critical Thinking, Logic, & Problem-Solving":

  • The 15 Most Essential Exercises to Supercharge Your Critical Thinking Prowess Starting Today!
  • Master the 3 Key Aspects of Identifying and Countering Fallacious Reasoning Like a Pro!
  • Ditch Intuition: Why Relying Solely on Gut Instincts Can Stall Your Progress and What to Do Instead!
  • How to Make Smarter Decisions Without Sacrificing Your Precious Time or Mental Well-being!
  • Unleash Your Critical Mindset: 4 Powerful Skills to Cultivate a Strategic Approach to Problem-Solving!
  • Master the Art of Inquiry: Develop 5 Effective Questioning Strategies for Deeper Understanding!
  • Overcoming Bias: 4 Proven Techniques to Identify and Challenge Biases, Elevating Your Ability to Accept Logical Arguments!
  • Harness the Power of Logic : Understand the Craft of Constructing Air-Tight Arguments for Maximum Persuasion!
  • Navigate Communication Minefields: Learn Proven Strategies to Communicate Effectively and Resolve Conflicts Like a Pro!

…and much, much more!

With your purchase, you’ll also receive FOUR EXCLUSIVE BONUSES :

  • How to Teach Kids Critical Thinking: Discover effective strategies for instilling critical thinking skills in children.
  • Applying Critical Thinking Skills in Everyday Life : Practical tips to enhance decision-making and problem-solving in your daily routine.
  • History of Critical Thinking: Discover the evolution and impact of critical thinking on modern society.
  • The Resilience Handbook : Build your resilience with insights on Stoic principles and the four main emotional intelligence skills.

Imagine how you'll feel once you've honed your critical thinking skills, conquered logical fallacies, and made confident decisions in all areas of your life. Picture the admiration from family and friends as you navigate challenges with ease and clarity.

So even if you’re a skeptic or feel like you’ve tried everything before, you can achieve remarkable results with "The Art Of Critical Thinking, Logic, & Problem-Solving" .

And if you have a burning desire to take control of your cognitive abilities and achieve your goals with confidence and precision, then scroll up and click “Add to Cart" now.

  • Book 3 of 3 Emotional Resilience
  • Print length 135 pages
  • Language English
  • Sticky notes On Kindle Scribe
  • Publication date May 21, 2024
  • File size 1486 KB
  • Page Flip Enabled
  • Word Wise Enabled
  • Enhanced typesetting Enabled
  • See all details

See full series

  • In This Series
  • Computers & Technology
  • Programming

The Stoic’s Guide to Emotional Mastery: Learn How to Stay Calm and Disciplined (Emotional Resilience Book 1)

From the Publisher

critical thinking book

Product details

  • ASIN ‏ : ‎ B0D4WJ8X22
  • Publication date ‏ : ‎ May 21, 2024
  • Language ‏ : ‎ English
  • File size ‏ : ‎ 1486 KB
  • Simultaneous device usage ‏ : ‎ Unlimited
  • Text-to-Speech ‏ : ‎ Enabled
  • Screen Reader ‏ : ‎ Supported
  • Enhanced typesetting ‏ : ‎ Enabled
  • X-Ray ‏ : ‎ Not Enabled
  • Word Wise ‏ : ‎ Enabled
  • Sticky notes ‏ : ‎ On Kindle Scribe
  • Print length ‏ : ‎ 135 pages
  • Page numbers source ISBN ‏ : ‎ B0D4YVWHPW
  • #2 in Communication in Management
  • #3 in Education Problem Solving
  • #18 in Business Communication Skills

About the author

Winston meskill.

Winston Meskill is an author, philosopher, and teacher of Stoicism. He was born and raised in Utah, where he still resides with his wife and three children. After working in the finance and banking industry for many years, he decided to focus on living off of his investments and pursuing his passions.

Winston discovered the Stoic philosophy after facing personal struggles in his life. He found himself overwhelmed by stress and unable to handle emotional conversations, which led him to make poor decisions. He felt like he had lost all joy in his life and was searching for a way to improve his well-being.

Through the teachings of Stoicism, Winston was able to transform his life and find a path to true happiness. He dedicated himself to exploring and practicing the philosophy, and eventually decided to write a book to share his knowledge and experience with others.

When he's not writing or teaching, Winston can often be found reading, painting, or spending time with his family. He is passionate about spreading the wisdom of Stoicism and helping others find peace and purpose in their lives.

Customer reviews

Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them.

To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyzed reviews to verify trustworthiness.

Reviews with images

Customer Image

  • Sort reviews by Top reviews Most recent Top reviews

Top reviews from the United States

There was a problem filtering reviews right now. please try again later..

critical thinking and logical fallacies

Report an issue

  • Amazon Newsletter
  • About Amazon
  • Accessibility
  • Sustainability
  • Press Center
  • Investor Relations
  • Amazon Devices
  • Amazon Science
  • Sell on Amazon
  • Sell apps on Amazon
  • Supply to Amazon
  • Protect & Build Your Brand
  • Become an Affiliate
  • Become a Delivery Driver
  • Start a Package Delivery Business
  • Advertise Your Products
  • Self-Publish with Us
  • Become an Amazon Hub Partner
  • › See More Ways to Make Money
  • Amazon Visa
  • Amazon Store Card
  • Amazon Secured Card
  • Amazon Business Card
  • Shop with Points
  • Credit Card Marketplace
  • Reload Your Balance
  • Amazon Currency Converter
  • Your Account
  • Your Orders
  • Shipping Rates & Policies
  • Amazon Prime
  • Returns & Replacements
  • Manage Your Content and Devices
  • Recalls and Product Safety Alerts
  • Conditions of Use
  • Privacy Notice
  • Consumer Health Data Privacy Disclosure
  • Your Ads Privacy Choices

IMAGES

  1. Critical Thinking and Logical Fallacies

    critical thinking and logical fallacies

  2. 30 Ways to Lose an Argument: The Logical Fallacies Collection

    critical thinking and logical fallacies

  3. Critical thinking Logical Fallacies t

    critical thinking and logical fallacies

  4. Logical Fallacies

    critical thinking and logical fallacies

  5. Learn To Think (part 2)

    critical thinking and logical fallacies

  6. Logical Fallacies Poster

    critical thinking and logical fallacies

VIDEO

  1. Logical Fallacies Part (1)

  2. Identify Logical Fallacies #tips for #criticalthinking

  3. Critical Thinking and Logical Fallacies

  4. Mastering Logical Fallacies: The Online Course

  5. How to Identify Logical Fallacies in Arguments and Discussions?

  6. How to Think More Logically with Kathy Gibbens

COMMENTS

  1. Critical Thinking and Decision-Making: Logical Fallacies

    Most logical fallacies can be spotted by thinking critically. Make sure to ask questions: Is logic at work here or is it simply rhetoric? Does their "proof" actually lead to the conclusion they're proposing? By applying critical thinking, you'll be able to detect logical fallacies in the world around you and prevent yourself from using them as ...

  2. Logical Fallacies

    Logical fallacies are leaps of logic that lead us to an unsupported conclusion. People may commit a logical fallacy unintentionally, due to poor reasoning, or intentionally, in order to manipulate others. ... In other words, a logical fallacy violates the principles of critical thinking because the premises do not sufficiently support the ...

  3. LOGOS: Critical Thinking, Arguments, and Fallacies

    This type of thinking seeks to preserve the original conclusion. Here, thinking and conclusions are policed, as to question the system is to threaten the system. And threats to the system demand a defensive response. Critical thinking is short-circuited in authoritarian systems so that the conclusions are conserved instead of being open for ...

  4. Introduction to Logic and Critical Thinking

    This is an introductory textbook in logic and critical thinking. The goal of the textbook is to provide the reader with a set of tools and skills that will enable them to identify and evaluate arguments. The book is intended for an introductory course that covers both formal and informal logic. As such, it is not a formal logic textbook, but is closer to what one would find marketed as a ...

  5. Fallacies

    This is why we would like to define fallacies more broadly as violations of the principles of critical thinking, whether or not the mistakes take the form of an argument. The study of fallacies is an application of the principles of critical thinking. Being familiar with typical fallacies can help us avoid them and help explain other people's ...

  6. What are Logical Fallacies?

    Logical fallacies are errors in reasoning or flawed arguments that can mislead or deceive. They often appear plausible but lack sound evidence or valid reasoning, undermining the credibility of an argument. These errors can be categorized into various types, such as ad hominem attacks, strawman arguments, and false cause correlations. Impact on Critical Thinking,

  7. PDF The Thinker's Guide To Fallacies

    The Foundation for Critical Thinking. To understand the human mind, understand self-deception. Anon. The word 'fallacy' derives from two Latin words, fallax ("deceptive") and fallere ("to deceive"). This is an important concept in human life because much human thinking deceives itself while deceiving others. The human mind has no ...

  8. Logical Fallacies

    Fallacies. Although there are more than two dozen types and subtypes of logical fallacies, these are the most common forms that you may encounter in writing, argument, and daily life: Begging the question, also known as circular reasoning, is a common fallacy that occurs when part of a claim—phrased in just slightly different words—is used ...

  9. 3.3: Fallacies

    The study of fallacies is an application of the principles of critical thinking. Being familiar with typical fallacies can help us avoid them. ... Developing a stronger understanding of inductive and deductive reasoning and a clearer grasp of the logical fallacies will assist you in navigating these discussions and creating stronger, more ...

  10. Critical Thinking

    Critical Thinking. Critical thinking is a widely accepted educational goal. Its definition is contested, but the competing definitions can be understood as differing conceptions of the same basic concept: careful thinking directed to a goal. Conceptions differ with respect to the scope of such thinking, the type of goal, the criteria and norms ...

  11. Critical Thinking

    Critical Thinking. Critical Thinking is the process of using and assessing reasons to evaluate statements, assumptions, and arguments in ordinary situations. ... Learning the terminology of systems like propositional and categorical logic and the names of the fallacies, and practicing applying these tools to hypothetical cases requires ...

  12. 11.3 Persuasive Reasoning and Fallacies

    Fallacies refer to flaws within the logic or reasoning of an argument. Ten fallacies of reasoning discussed in this chapter are hasty generalization, false analogy, false cause, false authority, false dilemma, ad hominem, slippery slope, red herring, and appeal to tradition. ... Being able to identify fallacies is an important critical thinking ...

  13. Logical Fallacies: What They Are and How to Counter Them

    For instance, the following is an example of a formal fallacy: Premise 1: If it's raining, then the sky will be cloudy. Premise 2: The sky is cloudy. Conclusion: It's raining. Though both the premises in this example are true, the argument is invalid, since there is a flaw in its logical structure.

  14. Fallacies

    The logical fallacies divide into the purely logical and the semi-logical fallacies. The purely logical fallacies are plain violations of syllogistic rules like undistributed middle and illicit process. ... Thagard, P., 2011, "Critical thinking and informal logic: neuropsychological perspectives," Informal Logic, 31: 152-70. Tindale, C. W ...

  15. 9.14: Common Logical Fallacies

    Bandwagon. The bandwagon fallacy is also sometimes called the "appeal to common belief" or "appeal to the masses" because it's all about getting people to do or think something because "everyone else is doing it" or "everything else thinks this.". "Everyone is getting tattoos in college, so you might as well do it too.".

  16. PDF 1 Critical Thinking: An Introduction. Logic and Logical Fallacies

    1 1 Critical Thinking: An Introduction. Logic and Logical Fallacies Lecture II 2 Truth Tables and Logical Operators zFace it…some things are either true or false (specifying this formally is called "propositional calculus") zA "proposition" is a meaningful statement zLimited number of operators: not, and, or, if…then, if and only if zTruth tables chart truth value of proposition by ...

  17. (PDF) Logical Fallacies: How They Undermine Critical Thinking and How

    Common Logical Fallacies That Interfere With Critical Thinking Logical fallacies should not be confused with cognitive biases. A logical fallacy occurs in the moment and is either intentionally or unintentionally used to win a dispute through 3 the use of unfounded assertions, invalid inferences, unsupported conclusions, or groundless arguments

  18. 2.5: Logical Fallacies

    Figure: One way to go about evaluating an argument for fallacies is to return to the concept of the three types of support for claims: ethos, logos, and pathos. As a quick reminder, Ethos is an argument that appeals to ethics, authority, and/or credibility. Logos is an argument that appeals to logic. Pathos is an argument that appeals to emotion.

  19. Logical Fallacies

    Critical Thinking - Writing Lab Tips and Strategies: Logical Fallacies. Home; Logical Fallacies; Logical Fallacies. Fallacies are fake or deceptive arguments, arguments that may sound good but prove nothing. Ad Hominem Argumen t: Attacking the person instead of the argument.

  20. Logical Fallacies

    Logical Fallacies. Logical fallacies are errors in reasoning that are based on poor or faulty logic. When presented in a formal argument, they can cause you to lose your credibility as a writer, so you have to be careful of them. Sometimes, writers will purposefully use logical fallacies to make an argument seem more persuasive or valid than it ...

  21. 9 Logical Fallacies You Need to Know to Master Critical Thinking

    The study of logic originates back to the Greek philosopher Aristotle (384-322 b.c.e), who started to systematically identify and list logical fallacies. The origin of logic is linked to the Greek logos, which translates to language, reason, or discourse. Logical fallacies are errors of reason that invalidate an argument. The use of logical ...

  22. How to Argue Against Common Fallacies

    Carrots are an excellent source of vitamin A, broccoli is rich in iron, and oranges and grapefruits have lots of Vitamin C. Plans to eliminate or reduce pesticides probably don't entail stopping the production of common vegetables: the suggestion that they do is an irrelevant red herring. 3. The Strawman Fallacy.

  23. 35. Recognizing Logical Fallacies for Better Critical Thinking

    In this episode I explain eight common logical fallacies—giving examples and ways to think more critically in today's ever-polarizing political climate. For extra resources to further your study, head to my Patreon. ... Recognizing Logical Fallacies for Better Critical Thinking Average customer ratings. Reviews - Please select the tabs below ...

  24. How To Improve Your Critical Thinking Skills

    Critical thinking guides every decision and belief. It's an intellectual process focused on making reasoned, logical judgments. It involves a series of components such as:. Gathering information: This involves gathering data and insights from various sources to create a comprehensive view with multiple perspectives on the topic.; Analyzing: This step involves breaking down the gathered ...

  25. Avoiding Logical Fallacies on Social Media

    Critical thinking is your best defense against logical fallacies. It involves analyzing information objectively before forming a judgment. On social media, always question the evidence presented ...

  26. Amazon.com: The Art of Critical Thinking, Logic, & Problem Solving: 15

    Here's just a tiny fraction of what you'll discover in "The Art Of Critical Thinking, Logic, & Problem-Solving": The 15 Most Essential Exercises to Supercharge Your Critical Thinking Prowess Starting Today! Master the 3 Key Aspects of Identifying and Countering Fallacious Reasoning Like a Pro!