Find anything you save across the site in your account

Why Is It So Hard to Be Rational?

By Joshua Rothman

A man draws a technical drawing of a cartoon head

I met the most rational person I know during my freshman year of college. Greg (not his real name) had a tech-support job in the same computer lab where I worked, and we became friends. I planned to be a creative-writing major; Greg told me that he was deciding between physics and economics. He’d choose physics if he was smart enough, and economics if he wasn’t—he thought he’d know within a few months, based on his grades. He chose economics.

We roomed together, and often had differences of opinion. For some reason, I took a class on health policy, and I was appalled by the idea that hospital administrators should take costs into account when providing care. (Shouldn’t doctors alone decide what’s best for their patients?) I got worked up, and developed many arguments to support my view; I felt that I was right both practically and morally. Greg shook his head. He pointed out that my dad was a doctor, and explained that I was engaging in “motivated reasoning.” My gut was telling me what to think, and my brain was figuring out how to think it. This felt like thinking, but wasn’t.

The next year, a bunch of us bought stereos. The choices were complicated: channels, tweeters, woofers, preamps. Greg performed a thorough analysis before assembling a capable stereo. I bought one that, in my opinion, looked cool and possessed some ineffable, tonal je ne sais quoi. Greg’s approach struck me as unimaginative, utilitarian. Later, when he upgraded to a new sound system, I bought his old equipment and found that it was much better than what I’d chosen.

In my senior year, I began considering graduate school. One of the grad students I knew warned me off—the job prospects for English professors were dismal. Still, I made the questionable decision to embark on a Ph.D. Greg went into finance. We stayed friends, often discussing the state of the world and the meta subject of how to best ascertain it. I felt overwhelmed by how much there was to know—there were too many magazines, too many books—and so, with Greg as my Virgil, I travelled deeper into the realm of rationality. There was, it turned out, a growing rationality movement, with its own ethos, thought style, and body of knowledge, drawn heavily from psychology and economics. Like Greg, I read a collection of rationality blogs—Marginal Revolution, Farnam Street, Interfluidity, Crooked Timber. I haunted the Web sites of the Social Science Research Network and the National Bureau of Economic Research, where I could encounter just-published findings; I internalized academic papers on the cognitive biases that slant our thinking, and learned a simple formula for estimating the “expected value” of my riskier decisions. When I was looking to buy a house, Greg walked me through the trade-offs of renting and owning (just rent); when I was contemplating switching careers, he stress-tested my scenarios (I switched). As an emotional and impulsive person by nature, I found myself working hard at rationality. Even Greg admitted that it was difficult work: he had to constantly inspect his thought processes for faults, like a science-fictional computer that had just become sentient.

Often, I asked myself, How would Greg think? I adopted his habit of tracking what I knew and how well I knew it, so that I could separate my well-founded opinions from my provisional views. Bad investors, Greg told me, often had flat, loosely drawn maps of their own knowledge, but good ones were careful cartographers, distinguishing between settled, surveyed, and unexplored territories. Through all this, our lives unfolded. Around the time I left my grad program to try out journalism, Greg swooned over his girlfriend’s rational mind, married her, and became a director at a hedge fund. His net worth is now several thousand times my own.

Meanwhile, half of Americans won’t get vaccinated; many believe in conspiracy theories or pseudoscience. It’s not that we don’t think—we are constantly reading, opining, debating—but that we seem to do it on the run, while squinting at trolls in our phones. This summer, on my phone, I read a blog post by the economist Arnold Kling, who noted that an unusually large number of books about rationality were being published this year, among them Steven Pinker’s “ Rationality: What It Is, Why It Seems Scarce, Why It Matters ” (Viking) and Julia Galef’s “ The Scout Mindset: Why Some People See Things Clearly and Others Don’t ” (Portfolio). It makes sense, Kling suggested, for rationality to be having a breakout moment: “The barbarians sack the city, and the carriers of the dying culture repair to their basements to write.” In a polemical era, rationality can be a kind of opinion hygiene—a way of washing off misjudged views. In a fractious time, it promises to bring the court to order. When the world changes quickly, we need strategies for understanding it. We hope, reasonably, that rational people will be more careful, honest, truthful, fair-minded, curious, and right than irrational ones.

And yet rationality has sharp edges that make it hard to put at the center of one’s life. It’s possible to be so rational that you are cut off from warmer ways of being—like the student Bazarov, in Ivan Turgenev’s “ Fathers and Sons ,” who declares, “I look up to heaven only when I want to sneeze.” (Greg, too, sometimes worries that he is rational to excess—that he is becoming a heartless boss, a cold fish, a robot.) You might be well-intentioned, rational, and mistaken, simply because so much in our thinking can go wrong. (“ RATIONAL , adj.: Devoid of all delusions save those of observation, experience and reflection,” Ambrose Bierce wrote, in his “Devil’s Dictionary.”) You might be rational and self-deceptive, because telling yourself that you are rational can itself become a source of bias. It’s possible that you are trying to appear rational only because you want to impress people; or that you are more rational about some things (your job) than others (your kids); or that your rationality gives way to rancor as soon as your ideas are challenged. Perhaps you irrationally insist on answering difficult questions yourself when you’d be better off trusting the expert consensus. Possibly, like Mr. Spock, of “ Star Trek ,” your rational calculations fail to account for the irrationality of other people. (Surveying Spock’s predictions, Galef finds that the outcomes Spock has determined to be impossible actually happen about eighty per cent of the time, often because he assumes that other people will be as “logical” as he is.)

Not just individuals but societies can fall prey to false or compromised rationality. In a 2014 book, “ The Revolt of the Public and the Crisis of Authority in the New Millennium ,” Martin Gurri, a C.I.A. analyst turned libertarian social thinker, argued that the unmasking of allegedly pseudo-rational institutions had become the central drama of our age: people around the world, having concluded that the bigwigs in our colleges, newsrooms, and legislatures were better at appearing rational than at being so, had embraced a nihilist populism that sees all forms of public rationality as suspect. COVID deniers and climate activists are different kinds of people, but they’re united in their frustration with the systems built by experts on our behalf—both groups picture élites shuffling PowerPoint decks in Davos while the world burns. From this perspective, the root cause of mass irrationality is the failure of rationalists. People would believe in the system if it actually made sense.

Lawyer has child sign waver before having pinata at their party.

Link copied

And yet modern life would be impossible without those rational systems; we must improve them, not reject them. We have no choice but to wrestle with rationality—an ideal that, the sociologist Max Weber wrote, “contains within itself a world of contradictions.” We want to live in a more rational society, but not in a falsely rationalized one. We want to be more rational as individuals, but not to overdo it. We need to know when to think and when to stop thinking, when to doubt and when to trust. Rationality is one of humanity’s superpowers. How do we keep from misusing it?

Writing about rationality in the early twentieth century, Weber saw himself as coming to grips with a titanic force—an ascendant outlook that was rewriting our values. He talked about rationality in many different ways. We can practice the instrumental rationality of means and ends (how do I get what I want?) and the value rationality of purposes and goals (do I have good reasons for wanting what I want?). We can pursue the rationality of affect (am I cool, calm, and collected?) or develop the rationality of habit (do I live an ordered, or “rationalized,” life?). Rationality was obviously useful, but Weber worried that it was turning each individual into a “cog in the machine,” and life into an “iron cage.” Today, rationality and the words around it are still shadowed with Weberian pessimism and cursed with double meanings. You’re rationalizing the org chart: are you bringing order to chaos, or justifying the illogical?

The Weberian definitions of rationality are by no means canonical. In “ The Rationality Quotient: Toward a Test of Rational Thinking ” (M.I.T.), from 2016, the psychologists Keith E. Stanovich, Richard F. West, and Maggie E. Toplak call rationality “a torturous and tortured term,” in part because philosophers, sociologists, psychologists, and economists have all defined it differently. For Aristotle, rationality was what separated human beings from animals. For the authors of “The Rationality Quotient,” it’s a mental faculty, parallel to but distinct from intelligence, which involves a person’s ability to juggle many scenarios in her head at once, without letting any one monopolize her attention or bias her against the rest. It’s because some people are better jugglers than others that the world is full of “smart people doing dumb things”: college kids getting drunk the night before a big exam, or travellers booking flights with impossibly short layovers.

Galef, who hosts a podcast called “ Rationally Speaking ” and co-founded the nonprofit Center for Applied Rationality, in Berkeley, barely uses the word “rationality” in her book on the subject. Instead, she describes a “scout mindset,” which can help you “to recognize when you are wrong, to seek out your blind spots, to test your assumptions and change course.” (The “soldier mindset,” by contrast, encourages you to defend your positions at any cost.) Galef tends to see rationality as a method for acquiring more accurate views. Pinker, a cognitive and evolutionary psychologist, sees it instrumentally, as “the ability to use knowledge to attain goals.” By this definition, to be a rational person you have to know things, you have to want things, and you have to use what you know to get what you want. Intentions matter: a person isn’t rational, Pinker argues, if he solves a problem by stumbling on a strategy “that happens to work.”

Introspection is key to rationality. A rational person must practice what the neuroscientist Stephen Fleming, in “ Know Thyself: The Science of Self-Awareness ” (Basic Books), calls “metacognition,” or “the ability to think about our own thinking”—“a fragile, beautiful, and frankly bizarre feature of the human mind.” Metacognition emerges early in life, when we are still struggling to make our movements match our plans. (“Why did I do that?” my toddler asked me recently, after accidentally knocking his cup off the breakfast table.) Later, it allows a golfer to notice small differences between her first swing and her second, and then to fine-tune her third. It can also help us track our mental actions. A successful student uses metacognition to know when he needs to study more and when he’s studied enough: essentially, parts of his brain are monitoring other parts.

In everyday life, the biggest obstacle to metacognition is what psychologists call the “illusion of fluency.” As we perform increasingly familiar tasks, we monitor our performance less rigorously; this happens when we drive, or fold laundry, and also when we think thoughts we’ve thought many times before. Studying for a test by reviewing your notes, Fleming writes, is a bad idea, because it’s the mental equivalent of driving a familiar route. “Experiments have repeatedly shown that testing ourselves—forcing ourselves to practice exam questions, or writing out what we know—is more effective,” he writes. The trick is to break the illusion of fluency, and to encourage an “awareness of ignorance.”

Fleming notes that metacognition is a skill. Some people are better at it than others. Galef believes that, by “calibrating” our metacognitive minds, we can improve our performance and so become more rational. In a section of her book called “Calibration Practice,” she offers readers a collection of true-or-false statements (“Mammals and dinosaurs coexisted”; “Scurvy is caused by a deficit of Vitamin C”); your job is to weigh in on the veracity of each statement while also indicating whether you are fifty-five, sixty-five, seventy-five, eighty-five, or ninety-five per cent confident in your determination. A perfectly calibrated individual, Galef suggests, will be right seventy-five per cent of the time about the answers in which she is seventy-five per cent confident. With practice, I got fairly close to “perfect calibration”: I still answered some questions wrong, but I was right about how wrong I would be.

There are many calibration methods. In the “equivalent bet” technique, which Galef attributes to the decision-making expert Douglas Hubbard, you imagine that you’ve been offered two ways of winning ten thousand dollars: you can either bet on the truth of some statement (for instance, that self-driving cars will be on the road within a year) or reach blindly into a box full of balls in the hope of retrieving a marked ball. Suppose the box contains four balls. Would you prefer to answer the question, or reach into the box? (I’d prefer the odds of the box.) Now suppose the box contains twenty-four balls—would your preference change? By imagining boxes with different numbers of balls, you can get a sense of how much you really believe in your assertions. For Galef, the box that’s “equivalent” to her belief in the imminence of self-driving cars contains nine balls, suggesting that she has eleven-per-cent confidence in that prediction. Such techniques may reveal that our knowledge is more fine-grained than we realize; we just need to look at it more closely. Of course, we could be making out detail that isn’t there.

Knowing about what you know is Rationality 101. The advanced coursework has to do with changes in your knowledge. Most of us stay informed straightforwardly—by taking in new information. Rationalists do the same, but self-consciously, with an eye to deliberately redrawing their mental maps. The challenge is that news about distant territories drifts in from many sources; fresh facts and opinions aren’t uniformly significant. In recent decades, rationalists confronting this problem have rallied behind the work of Thomas Bayes, an eighteenth-century mathematician and minister. So-called Bayesian reasoning—a particular thinking technique, with its own distinctive jargon—has become de rigueur.

There are many ways to explain Bayesian reasoning—doctors learn it one way and statisticians another—but the basic idea is simple. When new information comes in, you don’t want it to replace old information wholesale. Instead, you want it to modify what you already know to an appropriate degree. The degree of modification depends both on your confidence in your preëxisting knowledge and on the value of the new data. Bayesian reasoners begin with what they call the “prior” probability of something being true, and then find out if they need to adjust it.

Consider the example of a patient who has tested positive for breast cancer—a textbook case used by Pinker and many other rationalists. The stipulated facts are simple. The prevalence of breast cancer in the population of women—the “base rate”—is one per cent. When breast cancer is present, the test detects it ninety per cent of the time. The test also has a false-positive rate of nine per cent: that is, nine per cent of the time it delivers a positive result when it shouldn’t. Now, suppose that a woman tests positive. What are the chances that she has cancer?

When actual doctors answer this question, Pinker reports, many say that the woman has a ninety-per-cent chance of having it. In fact, she has about a nine-per-cent chance. The doctors have the answer wrong because they are putting too much weight on the new information (the test results) and not enough on what they knew before the results came in—the fact that breast cancer is a fairly infrequent occurrence. To see this intuitively, it helps to shuffle the order of your facts, so that the new information doesn’t have pride of place. Start by imagining that we’ve tested a group of a thousand women: ten will have breast cancer, and nine will receive positive test results. Of the nine hundred and ninety women who are cancer-free, eighty-nine will receive false positives. Now you can allow yourself to focus on the one woman who has tested positive. To calculate her chances of getting a true positive, we divide the number of positive tests that actually indicate cancer (nine) by the total number of positive tests (ninety-eight). That gives us about nine per cent.

Bayesian reasoning is an approach to statistics, but you can use it to interpret all sorts of new information. In the early hours of September 26, 1983, the Soviet Union’s early-warning system detected the launch of intercontinental ballistic missiles from the United States. Stanislav Petrov, a forty-four-year-old duty officer, saw the warning. He was charged with reporting it to his superiors, who probably would have launched a nuclear counterattack. But Petrov, who in all likelihood had never heard of Bayes, nevertheless employed Bayesian reasoning. He didn’t let the new information determine his reaction all on its own. He reasoned that the probability of an attack on any given night was low—comparable, perhaps, to the probability of an equipment malfunction. Simultaneously, in judging the quality of the alert, he noticed that it was in some ways unconvincing. (Only five missiles had been detected—surely a first strike would be all-out?) He decided not to report the alert, and saved the world.

Bayesian reasoning implies a few “best practices.” Start with the big picture, fixing it firmly in your mind. Be cautious as you integrate new information, and don’t jump to conclusions. Notice when new data points do and do not alter your baseline assumptions (most of the time, they won’t alter them), but keep track of how often those assumptions seem contradicted by what’s new. Beware the power of alarming news, and proceed by putting it in a broader, real-world context.

In a sense, the core principle is mise en place. Keep the cooked information over here and the raw information over there; remember that raw ingredients often reduce over heat. But the real power of the Bayesian approach isn’t procedural; it’s that it replaces the facts in our minds with probabilities. Where others might be completely convinced that G.M.O.s are bad, or that Jack is trustworthy, or that the enemy is Eurasia, a Bayesian assigns probabilities to these propositions. She doesn’t build an immovable world view; instead, by continually updating her probabilities, she inches closer to a more useful account of reality. The cooking is never done.

Applied to specific problems—Should you invest in Tesla? How bad is the Delta variant?—the techniques promoted by rationality writers are clarifying and powerful. But the rationality movement is also a social movement; rationalists today form what is sometimes called the “rationality community,” and, as evangelists, they hope to increase its size. The rationality community has its own lingua franca. If a rationalist wants to pay you a big compliment, she might tell you that you have caused her to “revise her priors”—that is, to alter some of her well-justified prior assumptions. (On her mental map, a mountain range of possibilities has gained or lost probabilistic altitude.) That same rationalist might talk about holding a view “on the margin”—a way of saying that an idea or fact will be taken into account, as a kind of tweak on a prior, the next time new information comes in. (Economists use the concept of “marginal utility” to describe how we value things in series: the first nacho is delightful, but the marginal utility of each additional nacho decreases relative to that of a buffalo wing.) She might speak about “updating” her opinions—a cheerful and forward-looking locution, borrowed from the statistical practice of “Bayesian updating,” which rationalists use to destigmatize the act of admitting a mistake. In use, this language can have a pleasingly deliberate vibe, evoking the feeling of an edifice being built. “Every so often a story comes along that causes me to update my priors,” the economist Tyler Cowen wrote, in 2019, in response to the Jeffrey Epstein case. “I am now, at the margin, more inclined to the view that what keeps many people on good behavior is simply inertia.”

In Silicon Valley, people wear T-shirts that say “Update Your Priors,” but talking like a rationalist doesn’t make you one. A person can drone on about base rates with which he’s only loosely familiar, or say that he’s revising his priors when, in fact, he has only ordinary, settled opinions. Google makes it easy to project faux omniscience. A rationalist can give others and himself the impression of having read and digested a whole academic subspecialty, as though he’d earned a Ph.D. in a week; still, he won’t know which researchers are trusted by their colleagues and which are ignored, or what was said after hours at last year’s conference. There’s a difference between reading about surgery and actually being a surgeon, and the surgeon’s priors are what we really care about. In a recent interview, Cowen—a superhuman reader whose blog, Marginal Revolution, is a daily destination for info-hungry rationalists—told Ezra Klein that the rationality movement has adopted an “extremely culturally specific way of viewing the world.” It’s the culture, more or less, of winning arguments in Web forums. Cowen suggested that to understand reality you must not just read about it but see it firsthand; he has grounded his priors in visits to about a hundred countries, once getting caught in a shoot-out between a Brazilian drug gang and the police.

Mushrooms in a clearing.

Clearly, we want people in power to be rational. And yet the sense that rationalists are somehow unmoored from direct experience can make the idea of a rationalist with power unsettling. Would such a leader be adrift in a matrix of data, more concerned with tending his map of reality than with the people contained in that reality? In a sketch by the British comedy duo Mitchell and Webb, a government minister charged with ending a recession asks his analysts if they’ve considered “killing all the poor.” “I’m not saying do it—I’m just saying run it through the computer and see if it would work,” he tells them. (After they say it won’t, he proposes “blue-skying” an even more senseless alternative: “Raise V.A.T. and kill all the poor.”) This caricature echoes a widespread skepticism of rationality as a value system. When the Affordable Care Act was wending its way through Congress, conservatives worried that similar proposals would pop up on “death panels,” where committees of rational experts would suggest lowering health-care costs by killing the aged. This fear, of course, was sharpened by the fact that we really do spend too much money on health care in the last few years of life. It’s up to rationalists to do the uncomfortable work of pointing out uncomfortable truths; sometimes in doing this they seem a little too comfortable.

In our personal lives, the dynamics are different. Our friends don’t have power over us; the best they can do is nudge us in better directions. Elizabeth Bennet, the protagonist of “ Pride and Prejudice ,” is intelligent, imaginative, and thoughtful, but it’s Charlotte Lucas, her best friend, who is rational. Charlotte uses Bayesian reasoning. When their new acquaintance, Mr. Darcy, is haughty and dismissive at a party, she gently urges Lizzy to remember the big picture: Darcy is “so very fine a young man, with family, fortune, everything in his favour”; in meeting him, therefore, one’s prior should be that rich, good-looking people often preen at parties; such behavior is not, in itself, revelatory. When Charlotte marries Mr. Collins, an irritating clergyman with a secure income, Lizzy is appalled at the match—but Charlotte points out that the success of a marriage depends on many factors, including financial ones, and suggests that her own chances of happiness are “as fair as most people can boast on entering the marriage state.” (In modern times, the base rates would back her up: although almost fifty per cent of marriages end in divorce, the proportion is lower among higher-income people.) It’s partly because of Charlotte’s example that Lizzy looks more closely at Mr. Darcy, and discovers that he is flawed in predictable ways but good in unusual ones. Rom-com characters often have passionate friends who tell them to follow their hearts, but Jane Austen knew that really it’s rational friends we need.

In fact, as Charlotte shows, the manner of a kind rationalist can verge on courtliness, which hints at deeper qualities. Galef describes a typically well-mannered exchange on the now defunct Web site ChangeAView. A male blogger, having been told that one of his posts was sexist, strenuously defended himself at first. Then, in a follow-up post titled “Why It’s Plausible I’m Wrong,” he carefully summarized the best arguments made against him; eventually, he announced that he’d been convinced of the error of his ways, apologizing not just to those he’d offended but to those who had sided with him for reasons that he now believed to be mistaken. Impressed by his sincere and open-minded approach, Galef writes, she sent the blogger a private message. Reader, they got engaged.

The rationality community could make a fine setting for an Austen novel written in 2021. Still, we might ask, How much credit should rationality get for drawing Galef and her husband together? It played a role, but rationality isn’t the only way to understand the traits she perceived. I’ve long admired my friend Greg for his rationality, but I’ve since updated my views. I think it’s not rationality, as such, that makes him curious, truthful, honest, careful, perceptive, and fair, but the reverse.

In “Rationality,” “The Scout Mindset,” and other similar books, irrationality is often presented as a form of misbehavior, which might be rectified through education or socialization. This is surely right in some cases, but not in all. One spring, when I was in high school, a cardinal took to flying at our living-room window, and my mother—who was perceptive, funny, and intelligent, but not particularly rational—became convinced that it was a portent. She’d sometimes sit in an armchair, waiting for it, watchful and unnerved. Similar events—a torn dollar bill found on the ground, a flat tire on the left side of the car rather than the right—could cast shadows over her mood for days, sometimes weeks. As a voter, a parent, a worker, and a friend, she was driven by emotion. She had a stormy, poetic, and troubled personality. I don’t think she would have been helped much by a book about rationality. In a sense, such books are written for the already rational.

My father, by contrast, is a doctor and a scientist by profession and disposition. When I was a kid, he told me that Santa Claus wasn’t real long before I figured it out; we talked about physics, computers, biology, and “Star Trek,” agreeing that we were Spocks, not Kirks. My parents divorced decades ago. But recently, when my mother had to be discharged from a hospital into a rehab center, and I was nearly paralyzed with confusion about what I could or should do to shape where she’d end up, he patiently, methodically, and judiciously walked me through the scenarios on the phone, exploring each forking path, sorting the inevitabilities from the possibilities, holding it all in his head and communicating it dispassionately. All this was in keeping with his character.

I’ve spent decades trying to be rational. So why did I feel paralyzed while trying to direct my mother’s care? Greg tells me that, in his business, it’s not enough to have rational thoughts. Someone who’s used to pondering questions at leisure might struggle to learn and reason when the clock is ticking; someone who is good at reaching rational conclusions might not be willing to sign on the dotted line when the time comes. Greg’s hedge-fund colleagues describe as “commercial”—a compliment—someone who is not only rational but timely and decisive. An effective rationalist must be able to short the mortgage market today, or commit to a particular rehab center now, even though we live in a world of Bayesian probabilities. I know, rationally, that the coronavirus poses no significant risk to my small son, and yet I still hesitated before enrolling him in daycare for this fall, where he could make friends. You can know what’s right but still struggle to do it.

Following through on your own conclusions is one challenge. But a rationalist must also be “metarational,” willing to hand over the thinking keys when someone else is better informed or better trained. This, too, is harder than it sounds. Intellectually, we understand that our complex society requires the division of both practical and cognitive labor. We accept that our knowledge maps are limited not just by our smarts but by our time and interests. Still, like Gurri’s populists, rationalists may stage their own contrarian revolts, repeatedly finding that no one’s opinions but their own are defensible. In letting go, as in following through, one’s whole personality gets involved. I found it possible to be metarational with my dad not just because I respected his mind but because I knew that he was a good and cautious person who had my and my mother’s best interests at heart. I trusted that, unlike the minister in the Mitchell and Webb sketch, he would care enough to think deeply about my problem. Caring is not enough, of course. But, between the two of us, we had the right ingredients—mutual trust, mutual concern, and a shared commitment to reason and to act.

The realities of rationality are humbling. Know things; want things; use what you know to get what you want. It sounds like a simple formula. But, in truth, it maps out a series of escalating challenges. In search of facts, we must make do with probabilities. Unable to know it all for ourselves, we must rely on others who care enough to know. We must act while we are still uncertain, and we must act in time—sometimes individually, but often together. For all this to happen, rationality is necessary, but not sufficient. Thinking straight is just part of the work. ♦

New Yorker Favorites

  • The day the dinosaurs died .
  • What if you could do it all over ?
  • A suspense novelist leaves a trail of deceptions .
  • The art of dying .
  • Can reading make you happier ?
  • A simple guide to tote-bag etiquette .
  • Sign up for our daily newsletter to receive the best stories from The New Yorker .

essay on rational thinking

By signing up, you agree to our User Agreement and Privacy Policy & Cookie Statement . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Among the A.I. Doomsayers

By Andrew Marantz

Arguing Ourselves to Death

By Jay Caspian Kang

Percival Everett Can’t Say What His Novels Mean

By Maya Binyam

Can an A.I. Make Plans?

By Cal Newport

  • Newsletters

Site search

  • Israel-Hamas war
  • 2024 election
  • TikTok’s fate
  • Supreme Court
  • All explainers
  • Future Perfect

Filed under:

The myth of rational thinking

Why our pursuit of rationality leads to explosions of irrationality.

Share this story

  • Share this on Facebook
  • Share this on Twitter
  • Share this on Reddit
  • Share All sharing options

Share All sharing options for: The myth of rational thinking

A ceramic cast of a human head being shattered into fragments.

Are human beings uniquely irrational creatures? And if we are, what are the consequences of basing our society on the opposite assumption?

These are questions Justin E.H. Smith, a philosopher at the University of Paris, takes up in his new book, Irrationality: A History of the Dark Side of Reason . He pokes holes in the story humans in the Western world have been telling themselves for centuries: that we were once blinkered by myth and superstition, but then the ancient Greeks discovered reason and, later, the Enlightenment cemented rationality as the highest value in human life.

Smith argues that this is a flattering but false story. Humans, he says, are hardly rational, and in fact, irrationality has defined much of human life and history. And the point is not merely academic. “The desire to impose rationality, to make people or society more rational,” he writes, “mutates ... into spectacular outbursts of irrationality.”

If Smith is right, that leaves us in a precarious position. If we can’t impose order on society, what are we supposed to do? Should we not strive to incentivize rationality as much as possible? Should we rethink the role of reason in human life?

I put these and other questions to Smith in a recent interview. A lightly edited transcript of our conversation follows.

Sean Illing

It’s hard to sum up the thesis of a book like this. How would you characterize it?

Justin E.H. Smith

The thesis is that the 20th-century philosophers T.W. Adorno and Max Horkheimer were basically correct when they argued that the Enlightenment world has an innate tendency to degenerate into myth, reason into unreason. And that this tendency of reason toward unreason is exacerbated by overly ambitious efforts to suppress or eliminate unreason. I think this is true both at the level of individual reason, or “psychology,” as well as at the level of society as a whole.

Some examples of this will help clarify what you mean, but first let’s back up a little. We have this idea, which goes all the way back to Aristotle, that human beings are distinguished from other animals by their capacity for reason. Is this a misleading picture? Should we not think of humans as uniquely rational creatures?

This is the traditional view. There is a counter-tradition, however, which says that human beings are the uniquely irrational animal. On this view, animals are rational to the extent that they do not get mired in deliberation and hesitation, but always just cut right to the chase and execute those actions that are perfectly suited to the sort of creatures they are, while we human beings stand there paralyzed by doubt and worry.

I am sympathetic to this view, though it can be carried too far. Obviously, we have been able to choose the correct course of action enough of the time to survive long enough to reproduce. We are a successful species, but not exceptionally so, and as far as I can tell not in virtue of being exceptionally well-endowed with reason.

That’s certainly one way to think of rationality. By that standard, you might say that human beings are cursed with too much consciousness, that our obsession with thinking creates more problems than it solves.

You might say that. But it’s not as if we think just because we are obsessed with thinking. Presumably, we human beings, as well as our hominid and pre-hominid ancestors, thought for a very long time before we began thinking about how this is possible and how it can go wrong.

Well, let’s talk about how it can go wrong. You write: “The desire to impose rationality, to make people or society more rational, mutates ... into spectacular outbursts of irrationality.” Can you give me an example of what you mean here?

The clearest instance in the book, which I set up as a sort of foundational myth, is the Pythagorean cult in the fifth century BC, which becomes so devoted to the perfect rationality of mathematics that it has trouble dealing with the discovery of the existence of irrational numbers . And so when one of its own, Hippasus of Metapontum, starts telling people outside the group that the world can’t be explained by mathematics alone, legend has it that the leader of the group had him drowned in a fit of anger.

The 18th-century French playwright and activist Olympe de Gouges is another example. In the spirit of reason, she famously argued that whatever the Universal Declaration of the Rights of Man — the civil rights document produced by the French Revolution in 1789 — said about men must also apply to women. And for that, the Jacobins cut her head off. So the response to her perfect rationality was extreme, murderous irrationality.

Something similar has followed countless revolutions since 1789, and many of these revolutions, notably the Marxist ones, have been at least nominally committed to the rational restructuring of society. I gather some Marxists are perfectly fine with seeing heads roll, and assume that it will only be the right heads that roll next time around and all present-day descendants of Olympe de Gouges will be spared. Or maybe they think it will never actually come to that.

essay on rational thinking

I think it’s obvious enough why humans are irrational, but where does this mania for rationality come from? Why are we so desperate to impose order on the world and society in the first place?

I think we just got a bit carried away. In the modern period, anyway, rationality became a value first in science and technology, where it plainly had its place. Making the correct inferences and following the correct method meant more scientific breakthroughs, which meant faster and more powerful machines.

But then the idea caught on that society itself is a big machine, and that the human being is a small sub-machine within the big machine of society, and that these two kinds of machine can be perfected in the same way that we have managed to perfect the steam engine, the telegraph, and so on.

But this has always been a misguided approach to psychology and politics, based on a weak metaphor drawn from a narrow domain of human life — mechanical engineering — in which we actually do have a pretty good understanding of how things work and of how problems are fixed.

I wonder where all this leaves us. There are obviously limits to reason, and we can only do so much to curb our worst impulses. At the same time, we want a world that is more intelligent, more wise, more compassionate. But we also have to base our social and political systems on a realistic model of human nature.

I don’t really have any formulas to offer here. Caution, pragmatism, case-by-case consideration of questions of justice, all seem advisable to me. I am not a political theorist, let alone a policymaker, and I think I manage to get to the end of the book without pretending to be either of these.

In spite of everything I’ve said, I believe in some amount of redistributive justice, including taking away about 99.9 percent of the fortunes of Bezos, Zuckerberg, and others, and turning the big tech companies into public utilities. I just think this should be done with good laws and broad public support, in such a way as to make it inevitable and ultimately painless for everyone (after all, these men would still be multimillionaires after the great confiscation).

The big error of so many schemes to rationally improve the human condition has been to spread the belief that there must be some great event in order for the new order of things to take hold, that rationality must be stoked by irrationality in order to work. That’s Leninism in a nutshell. But if society is ever going to be organized rationally, getting there is going to be very boring.

I’m curious how you think about progress in a big-picture sense. Reading your book, I thought about the story people like Steven Pinker tell, which is essentially that human history is a bumpy but nonetheless steady march of reason and progress. What’s wrong with this narrative?

Some of the data are pretty compelling about overall improvements in human life. If you look at India just in the past few years, the number of people with access to plumbing has skyrocketed, and disease has correspondingly gone down significantly. This is part of the legacy of Narendra Modi, and it is likely that the new era of authoritarian capitalism, perfected by China with runners-up like Modi, Erdogan, Bolsonaro, and Trump trying to get in on the game, will likely involve some improvements in the standard of living, at least for members of favored groups.

But I’m not sure this counts as overall improvement. For one thing, it is proving to be, in the regimes I’ve cited, at the expense of someone else that the improvements are carried out. What’s more, it will all be for nothing if any of the apocalyptic scenarios of the near future, which all serious people take seriously, comes to pass.

I take Pinker’s point about how quality of life has improved, and yet I look at our civilization’s incapacity to curtail its own destruction. I look at the fact that we’ve built a civilization predicated on the destruction of our own environment, and we’re unable to change course because we’re too blinkered by short-term interests. That doesn’t feel like progress to me.

Pinker probably sincerely believes he’s got an answer to this question, but honestly, when I consider his argument about the steady improvement of things, I just want to say: Well, let’s check back in 50 years. Is the Amazon [River] still there? Have the nuclear weapons been used?

And as for the Enlightenment and the purported achievement of perpetual peace in Western Europe in the 20th century, is it not plain that these two great victories had to do, first of all, with the pillaging of the rest of the world, and, second of all, with the fact that since the end of World War II, Western Europe has been surrounded by two superpowers ready to blow up the world if anyone makes a false move? Of course Europeans have been behaving themselves!

Do you see the global resurgence of nativism and right-wing populism as a rejection of Enlightenment principles?

It’s an old dialectic. The populist right is articulating most of its opinions and aims in terms derived from the Enlightenment — distorted terms, but still the same terms. The clearest example of this is the invocation of “freedom of speech” as a bludgeon for pushing extreme-right ideology into the center of public discourse.

Is that to say that the rational and technocratic world built on Enlightenment principles will always produce these sorts of reactionary crises? And what exactly are these populist movements rejecting?

I think it’s a question of managing these tendencies so that they don’t rise to crisis level: managing them without heavy-handedly suppressing them, and at the same time without nurturing them. That’s a delicate balance, as we’ve been seeing in the past few years.

When I was a kid, I assumed it was good to allow Nazi parades in Skokie or wherever, in part because I believed this was an effective form of containment. I see now that I took for granted that these parades would never build to anything truly threatening, and I think it’s impossible to think that anymore. The parades have moved online, but with that minor difference accounted for, they are much, much larger than they were a few decades ago.

I’ll ask what might seem like a strange question: What’s the utility of irrationality in human life? How do our irrational instincts actually serve us?

I place a lot of good things under the heading “irrationality” — not just dreams but also drunkenness, stonedness, artistic creation, listening to stories by the campfire, enjoyment of music and dancing, all sorts of orgiastic revelry, mass events like concerts and sports matches, and so on. I think most people would agree that these things make life worth living. And I think it’s impossible to account for the value of these things in purely utilitarian terms.

I could make a utilitarian case for some of those things, but I know what you mean. Maybe the point here is that the choice isn’t between a rational or irrational society, but rather a question about how best to manage the tensions between these two forces.

That’s right. It’s all about managing it rather than suppressing it or, the opposite approach, letting it run loose. An analogy: Scientists who study addiction have noted the problems biochemically for some people with eating disorders are scarcely distinguishable from drug addictions. You can advise a person to quit heroin cold turkey, but what do you tell them if they’re addicted to food? Irrationality is more like food in this regard than like illicit drugs. You can’t eliminate it, but obviously if you’re bingeing, you’ve got a problem and should get some help.

If you’re right that we can’t contain our own stupidity, how should we think about the role of reason in human life?

I think the value of reason is exaggerated by some and downplayed by others. It’s also very often invoked disingenuously, as a bludgeon to assert one’s will. This is what Nietzsche understood so well about the history of rationalist philosophy, and it’s what we see vividly illustrated countless times each day by Twitter’s “reply guys,” who are always ready to jump in with a “Well, actually” to pretty much anything anyone says, and particularly if that person is a woman or someone they think they can easily upstage.

Now, what they are saying might be true and reasonable, but it’s just obvious that the reason they’re saying it has to do with self-glorification, venal ambition, and other base motives. From a certain point of view, the history of philosophy is a history of reply guys who just happen to be very good at masking the true nature of their project. I don’t necessarily think that, but that thought nevertheless comes to me whenever I hear someone exalting too fervently the importance and the power of reason.

Sign up for the Future Perfect newsletter. Twice a week, you’ll get a roundup of ideas and solutions for tackling our biggest challenges: improving public health, decreasing human and animal suffering, easing catastrophic risks, and — to put it simply — getting better at doing good.

Will you help keep Vox free for all?

At Vox, we believe that clarity is power, and that power shouldn’t only be available to those who can afford to pay. That’s why we keep our work free. Millions rely on Vox’s clear, high-quality journalism to understand the forces shaping today’s world. Support our mission and help keep Vox free for all by making a financial contribution to Vox today.

We accept credit card, Apple Pay, and Google Pay. You can also contribute via

essay on rational thinking

Next Up In Future Perfect

Sign up for the newsletter today, explained.

Understand the world with a daily explainer plus the most compelling stories of the day.

Thanks for signing up!

Check your inbox for a welcome email.

Oops. Something went wrong. Please enter a valid email and try again.

A bicyclist pedals past a stone-fronted bank building, framed by large columns.

The safety net program trapping people in poverty

Joe Biden sits at a restaurant booth, surrounded by other diners. The wall behind them is painted with a vibrant mural.

Biden is doing everything to reach Latinos. Trump is barely trying.

essay on rational thinking

Why Republican federal judges are fighting among themselves

essay on rational thinking

Israel just raised the risk of a regional war

People standing near a destroyed truck.

Will Israel let aid workers in Gaza do their jobs?

A crowd of people protest the Florida Legislature’s plan to limit abortion rights.

The astonishing radicalism of Florida’s new ban on abortion

Oxford University Press

Oxford University Press's Academic Insights for the Thinking World

essay on rational thinking

What is the value of rationality, and why does it matter?

essay on rational thinking

The Value of Rationality

  • By Ralph Wedgwood
  • December 16 th 2017

Rationality is a widely discussed term. Economists and other social scientists routinely talk about rational agents making rational choices in light of their rational expectations. It’s also common in philosophy, especially in those areas that are concerned with understanding and evaluating human thinking, actions, and institutions. But what exactly is rationality? In the past, most philosophers assumed that the central notion of rationality is a normative or evaluative concept: to think rationally is to think ‘properly’ or ‘well’—in other words, to think as one ‘should’ think. Rational thinking is in a sense good thinking, while irrational thinking is bad. Recently, however, philosophers have raised several objections to that assumption.

First of all, how can it be true that you should never think irrationally, if you sometimes can’t help it?

Secondly, picture a scenario where you would be punished for thinking rationally—wouldn’t it be good to think irrationally in this case and bad to keep on thinking rationally?

And finally, rationality requires that our mental states (in other words, our beliefs, choices, and attitudes in general) are consistent and coherent. But why is that important, and what is so good about it?

Having considered these three arguments, we can now debate which side is right. Does thinking ‘rationally’ mean thinking ‘well ‘ and ‘properly’, or not? However, looking at both sides of the issue, it becomes evident that we still need considerable philosophical arguments and analysis before we can arrive at any conclusion. The reason why is because the problem itself is not clearly defined, since we don’t know the meaning of some of the key terms. Therefore, as a next step in the analysis, we will review some recent work in linguistics, specifically semantics.

Rationality, in the end, is the feature of your mind that guides you—ideally (if you’re lucky) towards the goal of getting things right.

Most linguists accept that every concept expressed by ‘should’ implies some concept that can be expressed by ‘can.’ But there are many different shades of ‘can.’ So, even if there is a strong sense of ‘can’ that makes it true that you ‘can’t help’ thinking as irrationally as you do, there could still be a weaker sense of ‘can’ that makes it true that you ‘can’ think more rationally than you do. In this way, we may be able to answer the first objection: the sense in which it is true that we ‘should think rationally’ implies one of these weaker senses of ‘can’, which make it true that we ‘can’ think more rationally than we do.

The same sort of differentiation may help with the second and third objections. The meaning of terms like ‘good’, ‘well’, and ‘properly’ changes in different circumstances. Think about the scenario in which you would be punished for thinking rationally, and rewarded for doing the opposite. In one sense of good, it is good in this case to think irrationally, but in another sense, it remains good for you to think rationally, because rational thinking in itself is always good.

Instead of answering our questions, however, this line of argument raises more, because what we need to do now is define this sense of ‘good’, in which rational thinking is always ‘good.’ But here is a proposal about how to answer these further questions. When you have a belief, or when you choose a course of action, you have a goal—the goal of getting things right. After all, it would be absurd and nonsensical to say, “I know that this is the right thing to believe, but why should I believe it?” To get things right, your beliefs and choices must fit with the external world.

However, your beliefs and choices cannot be directly guided by what is happening in the external world. They can only be directly guided by what is going in your mind. Rationality, in the end, is the feature of your mind that guides you—ideally (if you’re lucky) towards the goal of getting things right.

Suppose that your belief does get things right in this way. The fact that you succeeded in getting things right is explained in part by the fact that you were thinking rationally. In other words, rationality matters because rationality is the means by which we pursue the goal of getting things right.

Featured image credit: Photograph of a boy in front of a chess landscape by Positive Images. Public domain via Pixabay .

Ralph Wedgwood is a Professor of Philosophy at University of Southern California. He is the author of The Value of Rationality , The Nature of Normativity , and around fifty articles in various volumes and philosophy journals.

Our Privacy Policy sets out how Oxford University Press handles your personal information, and your rights to object to your personal information being used for marketing to you or being processed as part of our business activities.

We will only use your personal information to register you for OUPblog articles.

Or subscribe to articles in the subject area by email or RSS

Related posts:

essay on rational thinking

Recent Comments

Perhaps we should also view `rationality’ from a `reasonable’ perspective.

For instance, one could reasonably argue that, both qualitatively and quantitatively, any belief (i.e., the perceived content of a well-defined declarative sentence) is necessarily associated with a suitably-defined truth assignation that must fall into one or more of the following three categories:

(i) beliefs that we hold to be `true’ in an absolute, Platonic, sense, and have in common with others holding beliefs similarly;

(ii) beliefs that we hold to be `true’—short of Platonic belief—since they can be treated as self-evident, and have in common with others who also hold them as similarly self-evident;

(iii) beliefs that we agree to define as `true’ on the basis of a convention, and have in common with others who accept the same convention for assigning truth values to such assertions.

Clearly the three categories of beliefs have associated truth assignations with increasing degrees of objective accountability (i.e., accountability based on evidence-based reasoning) which must, in turn, influence the psyche of whoever is exposed to a particular category at a particular moment of time.

Thus, zealots might be categorised as irrational agents since they accept all three as definitive; prophets as reasonable agents since they hold only (ii) and (iii) as definitive; and scientists as rational agents since they hold only (iii) as definitive.

If rational thinking is “good” or “proper” thinking, it has to be better than something else. The article suggests “irrational” thinking, but I don’t find that much help. I suspect most of us would contrast “rational” thinking with “emotional” thinking, which suggests a difference, not just in outcomes, but two fundamentally different kinds of thinking, each rising from very different activities in the brain and body.

I also suspect most of us would consider “rational” thinking to be a later, and more refined evolutionary development – a specifically human kind of thinking – an historical development that came into its own during the time of classical Greek culture.

To evaluate the value and importance of “rational” thinking it should help to know how we came to have it. I suggest “rational” thinking developed as a way to reduce uncertainty in our increasingly complex, culturally driven species.

Most creatures live “in the moment”. They don’t know about tomorrow afternoon, much less a week from Friday and so they have not developed, and could not use a kind of thinking that considered all the possible events between now and then. We live in the moment, the hour, the day, the week, the year, the generation, our cultural age, in history. For us, necessity has been the mother of invention. It has brought us stories, history, writing, counting, money, the Rosetta stone, books, libraries, newspapers, radio, television, computers, and artificial intelligence. None of this could come from the kind of thinking that came packaged in the box when our species was new.

We need to plan for layer upon layer of overlapping slices of time and so our level of uncertainty and our need for information is not only vastly greater than any other species, it is continually increasing. “Rational” thinking has been our answer to that need. It has worked pretty well, but at some level we don’t like it. Compared to “emotional” thinking, to going with our “gut” it seems contrived, slightly unnatural.

The author asks, “What is the value of rationality and why does it matter?” I have drifted pretty far from his analysis, but this where the question led me. I ask the author’s indulgence and thank him for making me think.

Comments are closed.

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


Academic tools.

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

Rationalism vs. Empiricism

In its most general terms, the dispute between rationalism and empiricism has been taken to concern the extent to which we are dependent upon experience in our effort to gain knowledge of the external world. It is common to think of experience itself as being of two kinds: sense experience, involving our five world-oriented senses, and reflective experience, including conscious awareness of our mental operations. The distinction between the two is drawn primarily by reference to their objects: sense experience allows us to acquire knowledge of external objects, whereas our awareness of our mental operations is responsible for the acquisition of knowledge of our minds. In the dispute between rationalism and empiricism, this distinction is often neglected; rationalist critiques of empiricism usually contend that the latter claims that all our ideas originate with sense experience.

It is generally agreed that most rationalists claim that there are significant ways in which our concepts and knowledge are gained independently of sense experience. To be a rationalist, however, does not require one to claim that our knowledge is acquired independently of any experience: at its core, the Cartesian Cogito depends on our reflective, intuitive awareness of the existence of occurrent thought. Rationalists generally develop their view in two steps. First, they argue that there are cases where the content of our concepts or knowledge outstrips the information that sense experience can provide. Second, they construct accounts of how reason, in some form or other, provides that additional information about the external world.

Most empiricists present complementary lines of thought. First, they develop accounts of how experience alone -- sense experience, reflective experience, or a combination of the two -- provides the information that rationalists cite, insofar as we have it in the first place. Second, while empiricists attack the rationalists’ accounts of how reason is a primary source of concepts or knowledge, they show that reflective understanding can and usually does supply some of the missing links (famously, Locke believed that our idea of substance, in general, is a composite idea, incorporating elements derived from both sensation and reflection, e.g. Essay, 2.23.2).

The distinction between rationalism and empiricism is not without problems. One of the main issues is that almost no author falls neatly into one camp or another: it has been argued that Descartes, for instance, who is commonly regarded as a representative rationalist (at least with regard to metaphysics), had clear empiricist leanings (primarily with regard to natural philosophy, where sense experience plays a crucial role, according to Clarke 1982). Conversely, Locke, who is thought to be a paradigmatic empiricist, argued that reason is on equal footing with experience, when it comes to the knowledge of certain things, most famously of moral truths ( Essay, 4.3.18). In what follows, we clarify what this distinction has traditionally been taken to apply to, as well as point out its (by now) widely-recognized shortcomings.

1.1 Rationalism

1.2 empiricism, 2. the intuition/deduction thesis, 3. the innate knowledge thesis, 4. the innate concept thesis, other internet resources, related entries, 1. introduction.

The dispute between rationalism and empiricism takes place primarily within epistemology, the branch of philosophy devoted to studying the nature, sources, and limits of knowledge. Knowledge itself can be of many different things and is usually divided among three main categories: knowledge of the external world, knowledge of the internal world or self-knowledge, and knowledge of moral and/or aesthetical values. We may find that there are category-specific conditions that must be satisfied for knowledge to occur and that it is easier or more difficult to shape certain questions and answers, depending on whether we focus on the external world or on the values. However, some of the defining questions of general epistemology include the following.

What is the nature of propositional knowledge, knowledge that a particular proposition about the world, ourselves, morality, or beauty is true?

To know a proposition, we must believe it and it must be true, but something more is required, something that distinguishes knowledge from a lucky guess. Let’s call this additional element ‘warrant’. A good deal of philosophical work has been invested in trying to determine the nature of warrant.

How can we gain knowledge?

We can form true beliefs just by making lucky guesses. How to gain warranted beliefs is less clear. Moreover, to know the external world or anything about beauty, for instance, we must be able to think about the external world or about beauty, and it is unclear how we gain the concepts we use in thought or what assurance, if any, we have that the ways in which we divide up the world using our concepts correspond to divisions that actually exist.

What are the limits of our knowledge?

Some aspects of the external world, ourselves, or the moral and aesthetical values may be within the limits of our thought but beyond the limits of our knowledge; faced with competing descriptions of them, we cannot know which description is true. Some aspects of the external world, ourselves, or the moral and aesthetical values may even be beyond the limits of our thought, so that we cannot form intelligible descriptions of them, let alone know that a particular description is true.

The disagreement between rationalism and empiricism primarily concerns the second question, regarding the sources of our concepts and knowledge. In some instances, the disagreement on this topic results in conflicting responses to the other questions as well. The disagreement may extend to incorporate the nature of warrant or where the limits of our thought and knowledge are. Our focus here will be on the competing rationalist and empiricist responses to the second question.

There are three main theses that are usually seen as relevant for drawing the distinction between rationalism and empiricism, with a focus on the second question. While the first thesis has been traditionally seen as distinguishing between rationalism and empiricism, scholars now mostly agree that most rationalists and empiricists abide by the so-called Intuition/Deduction thesis , concerning the ways in which we become warranted in believing propositions in a particular subject area.

The Intuition/Deduction Thesis : Some propositions in a particular subject area, S, are knowable by us by intuition alone; still others are knowable by being deduced from intuited propositions.

Intuition is a form of direct, immediate insight. Intuition has been likened to (a sort of internal) perception by most rationalists and empiricists alike. Intellectually grasping a proposition, we just “see” it to be true in such a way as to form a true, warranted belief in it. (As discussed in Section 2 below, the nature of this intellectual “seeing” needs explanation.) Deduction is a process in which we derive conclusions from intuited premises through valid arguments, ones in which the conclusion must be true if the premises are true. We intuit, for example, that the number three is prime and that it is greater than two. We then deduce from this knowledge that there is a prime number greater than two. Intuition and deduction thus provide us with knowledge that is independent, for its justification, of experience. This type of knowledge, since Kant, is commonly called “ a priori ”.

We can generate different versions of the Intuition/Deduction thesis by substituting different subject areas for the variable ‘S’. Several rationalists and empiricists take mathematics to be knowable by intuition and deduction. Some place ethical truths in this category. Some include metaphysical claims, such as that God exists, we have free will, and our mind and body are distinct substances.

The second thesis that is relevant to the distinction between rationalism and empiricism is the Innate Knowledge thesis .

The Innate Knowledge Thesis : We have knowledge of some truths in a particular subject area, S, as part of our nature.

The Innate Knowledge thesis asserts the existence of knowledge whose source is our own nature: we are born with this knowledge; it doesn’t depend, for its justification, on our accessing it via particular experiences. Our innate knowledge is not learned through either experience or intuition/deduction. It is just part of our nature. Experiences may trigger a process by which we bring this knowledge to consciousness, but these experiences do not provide us with the knowledge itself. It has in some way been with us all along. According to some rationalists, we gained the knowledge in an earlier existence. According to others, God provided us with it at creation. Still others say it is part of our nature through natural selection.

We get different versions of the Innate Knowledge thesis by substituting different subject areas for the variable ‘S’. The more subjects included within the range of the thesis or the more controversial the claim to have knowledge in them, the more radical the form of rationalism. Stronger and weaker understandings of warrant yield stronger and weaker versions of the thesis as well. Empiricists reject this thesis: Locke, for instance, dedicates the whole first book of the Essay to show that such knowledge, even if it existed, would be of little use to us.

The third important thesis that is relevant to the distinction between rationalism and empiricism is the Innate Concept thesis.

The Innate Concept Thesis : We have some of the concepts we employ in a particular subject area, S, as part of our rational nature.

According to the Innate Concept thesis, some of our concepts are not gained from experience. They are part of our rational nature in such a way that, while sense experiences may trigger a process by which they are brought to consciousness, experience does not provide the concepts or determine the information they contain. Some claim that the Innate Concept thesis is entailed by the Innate Knowledge Thesis; a particular instance of knowledge can only be innate if the concepts that are contained in the known proposition are also innate. This is Locke’s position ( Essay , 1.4.1). Others, such as Carruthers, argue against this connection (1992, pp. 53–54). The content and strength of the Innate Concept thesis varies with the concepts claimed to be innate. The more a concept seems removed from experience and the mental operations we can perform on experience the more plausibly it may be claimed to be innate. Since we do not experience perfect triangles but do experience pains, our concept of the former is a more promising candidate for being innate than our concept of the latter.

The Intuition/Deduction thesis, the Innate Knowledge thesis, and the Innate Concept thesis are essential to rationalism. Since the Intuition/Deduction thesis is equally important to empiricism, the focus in what follows will be on the other two theses. To be a rationalist is to adopt at least one of them: either the Innate Knowledge thesis, regarding our presumed propositional innate knowledge, or the Innate Concept thesis, regarding our supposed innate knowledge of concepts.

Rationalists vary the strength of their view by adjusting their understanding of warrant. Some take warranted beliefs to be beyond even the slightest doubt and claim that intuition provide beliefs of this high epistemic status. Others interpret warrant more conservatively, say as belief beyond a reasonable doubt, and claim that intuition provide beliefs of that caliber. Still another dimension of rationalism depends on how its proponents understand the connection between intuition, on the one hand, and truth, on the other. Some take intuition to be infallible, claiming that whatever we intuit must be true. Others allow for the possibility of false intuited propositions.

Two other closely related theses are generally adopted by rationalists, although one can certainly be a rationalist without adopting either of them. The first is that sense experience cannot provide what we gain from reason.

The Indispensability of Reason Thesis : The knowledge we gain in subject area, S, by intuition and deduction, as well as the ideas and instances of knowledge in S that are innate to us, could not have been gained by us through sense experience.

The second is that reason is superior to sense experience as a source of knowledge.

The Superiority of Reason Thesis : The knowledge we gain in subject area S by intuition and deduction or have innately is superior to any knowledge gained by sense experience.

How reason is superior needs explanation, and rationalists have offered different accounts. One view, generally associated with Descartes ( Rules, Rule II and Rule III, pp. 1–4), is that what we know by intuition is certain, beyond even the slightest doubt, while what we believe, or even know, on the basis of sense experience is at least somewhat uncertain. Another view, generally associated with Plato ( Republic 479e-484c), locates the superiority of a priori knowledge in the objects known. What we know by reason alone, a Platonic form, say, is superior in an important metaphysical way, e.g. unchanging, eternal, perfect, a higher degree of being, to what we are aware of through sense experience.

Most forms of rationalism involve notable commitments to other philosophical positions. One is a commitment to the denial of scepticism for at least some area of knowledge. If we claim to know some truths by intuition or deduction or to have some innate knowledge, we obviously reject scepticism with regard to those truths. Rationalism in the form of the Intuition/Deduction thesis is also committed to epistemic foundationalism, the view that we know some truths without basing our belief in them on any others and that we then use this foundational knowledge to know more truths.

Empiricists also endorse the Intuition/Deduction thesis, but in a more restricted sense than the rationalists: this thesis applies only to relations of the contents of our minds, not also about empirical facts, learned from the external world. By contrast, empiricists reject the Innate Knowledge and Innate Concept theses. Insofar as we have knowledge in a subject, our knowledge is gained , not only triggered, by our experiences, be they sensorial or reflective. Experience is, thus, our only source of ideas. Moreover, they reject the corresponding version of the Superiority of Reason thesis. Since reason alone does not give us any knowledge, it certainly does not give us superior knowledge. Empiricists need not reject the Indispensability of Reason thesis, but most of them do.

The main characteristic of empiricism, however, is that it endorses a version of the following claim for some subject area:

The Empiricism Thesis : We have no source of knowledge in S or for the concepts we use in S other than experience.

To be clear, the Empiricism thesis does not entail that we have empirical knowledge. It entails that knowledge can only be gained, if at all , by experience. Empiricists may assert, as some do for some subjects, that the rationalists are correct to claim that experience cannot give us knowledge. The conclusion they draw from this rationalist lesson is that we do not know at all. This is, indeed, Hume's position with regard to causation, which, he argues, is not actually known, but only presupposed to be holding true, in virtue of a particular habit of our minds.

We have stated the basic claims of rationalism and empiricism so that each is relative to a particular subject area. Rationalism and empiricism, so relativized, need not conflict. We can be rationalists in mathematics or a particular area of mathematics and empiricists in all or some of the physical sciences. Rationalism and empiricism only conflict when formulated to cover the same subject. Then the debate, Rationalism vs. Empiricism, is joined. The fact that philosophers can be both rationalists and empiricists has implications for the classification schemes often employed in the history of philosophy, especially the one traditionally used to describe the Early Modern Period of the seventeenth and eighteenth centuries leading up to Kant. It is standard practice to group the philosophers of this period as either rationalists or empiricists and to suggest that those under one heading share a common agenda in opposition to those under the other. Thus, Descartes, Spinoza and Leibniz are the Continental Rationalists in opposition to Locke, Hume, and Reid, the British Empiricists. Such general classification schemes should only be adopted with great caution. The views of the individual philosophers are a lot more subtle and complex than the simple-minded classification suggests. (See Loeb (1981) and Kenny (1986) for important discussions of this point.) Locke rejects rationalism in the form of any version of the Innate Knowledge or Innate Concept theses, but he nonetheless adopts the Intuition/Deduction thesis with regard to our knowledge of God’s existence, in addition to our knowledge of mathematics and morality. Descartes and Locke have remarkably similar views on the nature of our ideas, even though Descartes takes many to be innate, while Locke ties them all to experience. The rationalist/empiricist classification also encourages us to expect the philosophers on each side of the divide to have common research programs in areas beyond epistemology. Thus, Descartes, Spinoza and Leibniz are mistakenly seen as applying a reason-centered epistemology to a common metaphysical agenda, with each trying to improve on the efforts of the one before, while Locke, Hume, and Reid are mistakenly seen as gradually rejecting those metaphysical claims, with each consciously trying to improve on the efforts of his predecessors. It is also important to note that the rationalist/empiricist distinction is not exhaustive of the possible sources of knowledge. One might claim, for example, that we can gain knowledge in a particular area by a form of Divine revelation or insight that is a product of neither reason nor sense experience. In short, when used carelessly, the labels ‘rationalist’ and ‘empiricist,’ as well as the slogan that is the title of this essay, ‘Rationalism vs. Empiricism,’ can impede rather than advance our understanding.

An important wrinkle for using this classification scheme in the history of philosophy is that it leaves out discussions of philosophical figures who did not focus their efforts on understanding whether innate knowledge is possible or even fruitful to have. Philosophy in the early modern period, in particular, is a lot richer than this artificial, simplifying distinction makes it sound. There is no clear way of grouping Hobbes with either camp, let alone Elizabeth of Bohemia, Anne Conway, George Berkeley, Émilie du Châtelet, or Mary Shepherd. This distinction, initially applied by Kant, is responsible for giving us a very restrictive philosophical canon, which does not take into account developments in the philosophy of emotions, philosophy of education, and even disputes in areas of philosophy considered more mainstream, like ethics and aesthetics.

Unless restricted to debates regarding the possibility of innate knowledge, this distinction is best left unused. The most interesting form of the debate occurs when we take the relevant subject to be truths about the external world, the world beyond our own minds. A full-fledged rationalist with regard to our knowledge of the external world holds that some external world truths are and must be innate and that this knowledge is superior to any that sense experience could ever provide. The full-fledged empiricist about our knowledge of the external world replies that, when it comes to the nature of the world beyond our own minds, experience is our sole source of information. Reason might inform us of the relations among our ideas, but those ideas themselves can only be gained, and any truths about the external reality they represent can only be known, on the basis of experience. This debate concerning our knowledge of the external world will generally be our main focus in what follows.

Historically, the rationalist/empiricist dispute in epistemology has extended into the area of metaphysics, where philosophers are concerned with the basic nature of reality, including the existence of God and such aspects of our nature as free-will and the relation between the mind and body. Several rationalists (e.g., Descartes, Meditations ) have presented metaphysical theories, which they have claimed to know by intuition and/or deduction alone. Empiricists (e.g., Hume, Treatise) have rejected the theories as either speculation, beyond what we can learn from experience, or nonsensical attempts to describe aspects of the world beyond the concepts experience can provide. The debate raises the issue of metaphysics as an area of knowledge. Kant puts the driving assumption clearly:

The very concept of metaphysics ensures that the sources of metaphysics can’t be empirical. If something could be known through the senses, that would automatically show that it doesn’t belong to metaphysics; that’s an upshot of the meaning of the word ‘metaphysics.’ Its basic principles can never be taken from experience, nor can its basic concepts; for it is not to be physical but metaphysical knowledge, so it must be beyond experience. ( Prolegomena , Preamble, I, p. 7)

The possibility then of metaphysics so understood, as an area of human knowledge, hinges on how we resolve the rationalist/empiricist debate. The debate also extends into ethics. Some moral objectivists (e.g., Ross 1930 and Huemer 2005) take us to know some fundamental objective moral truths by intuition, while some moral skeptics, who reject such knowledge (e.g., Mackie 1977), find the appeal to a faculty of moral intuition utterly implausible. More recently, the rationalist/empiricist debate has extended to discussions (e.g., Bealer 1999 and Alexander & Weinberg 2007) of the very nature of philosophical inquiry: to what extent are philosophical questions to be answered by appeals to reason or experience?

The Intuition/Deduction thesis claims that we can know some propositions by intuition and still more by deduction. Since traditionally this thesis was thought to be rejected by empiricists and adopted only by rationalists, it is useful to become more familiar with it. In a very narrow sense, only rationalists seem to adopt it. However, the current consensus is that most empiricists (e.g., Locke, Hume, Reid) have been willing to accept a version of the thesis, namely inasmuch as it is restricted to propositions solely about the relations among our own concepts. We can, they agree, know by intuition that our concept of God includes our concept of omniscience. Just by examining the concepts, we can intellectually grasp that the one includes the other. The debate between rationalists and empiricists is joined when the former assert, and the latter deny, the Intuition/Deduction thesis with regard to propositions that contain substantive information about the external world. Rationalists, such as Descartes, have claimed that we can know by intuition and deduction that God exists and created the world, that our mind and body are distinct substances, and that the angles of a triangle equal two right angles, where all of these claims are truths about an external reality independent of our thought. Such substantive versions of the Intuition/Deduction thesis are our concern in this section.

One defense of the Intuition/Deduction thesis assumes that we know some substantive external world truths, adds an analysis of what knowledge requires, and concludes that our knowledge must result from intuition and deduction. Rationalists and empiricists alike claim that certainty is required for scientia (which is a type of absolute knowledge of the necessary connections that would explain why certain things are a certain way) and that certainty about the external world is beyond what empirical evidence can provide. Empiricists seem happy to then conclude that the type of knowledge of the external world that we can acquire does not have this high degree of certainty and is, thus, not scientia . This is because we can never be sure our sensory impressions are not part of a dream or a massive, demon orchestrated, deception. A rationalist like Descartes of the Meditations , claims that only intuition can provide the certainty needed for such knowledge. This, after his arguing in the Rules that, when we “review all the actions of the intellect by means of which we are able to arrive at a knowledge of things with no fear of being mistaken,” we “recognize only two: intuition and deduction” ( Rules , Rule III, p. 3).

This line of argument is one of the least compelling in the rationalist arsenal. First, the assumption that knowledge requires certainty comes at a heavy cost, as it rules out so much of what we commonly take ourselves to know. Second, as many contemporary rationalists accept, intuition is not always a source of certain knowledge. The possibility of a deceiver gives us a reason to doubt our intuitions as well as our empirical beliefs. For all we know, a deceiver might cause us to intuit false propositions, just as one might cause us to have perceptions of nonexistent objects. Descartes’s classic way of meeting this challenge in the Meditations is to argue that we can know with certainty that no such deceiver interferes with our intuitions and deductions. They are infallible, as God guarantees their truth. The problem, known as the Cartesian Circle, is that Descartes’s account of how we gain this knowledge begs the question, by attempting to deduce the conclusion that all our intuitions are true from intuited premises. Moreover, his account does not touch a remaining problem that he himself notes ( Rules , Rule VII, p. 7): Deductions of any appreciable length rely on our fallible memory.

A more plausible argument for the Intuition/Deduction thesis again assumes that we know some particular, external world truths, and then appeals to the nature of what we know, rather than to the nature of knowledge itself, to argue that our knowledge must result from intuition and deduction. Leibniz, in New Essays , tells us the following:

The senses, although they are necessary for all our actual knowledge, are not sufficient to give us the whole of it, since the senses never give anything but instances, that is to say particular or individual truths. Now all the instances which confirm a general truth, however numerous they may be, are not sufficient to establish the universal necessity of this same truth, for it does not follow that what happened before will happen in the same way again. … From which it appears that necessary truths, such as we find in pure mathematics, and particularly in arithmetic and geometry, must have principles whose proof does not depend on instances, nor consequently on the testimony of the senses, although without the senses it would never have occurred to us to think of them… ( New Essays , Preface, pp. 150–151)

Leibniz goes on to describe our mathematical knowledge as “innate,” and his argument is more commonly directed to support the Innate Knowledge thesis rather than the Intuition/Deduction thesis. For our purposes here, we can relate it to the latter, however: We have substantive knowledge about the external world in mathematics, and what we know in that area, we know to be necessarily true. Experience cannot warrant beliefs about what is necessarily the case. Hence, experience cannot be the source of our knowledge. The best explanation of our knowledge is that we gain it by intuition and deduction. Leibniz mentions logic, metaphysics, and morals as other areas in which our knowledge similarly outstrips what experience can provide. Judgments in logic and metaphysics involve forms of necessity beyond what experience can support. Judgments in morals involve a form of obligation or value that lies beyond experience, which only informs us about what is the case rather than about what ought to be.

The strength of this argument varies with its examples of purported knowledge. Insofar as we focus on controversial claims in metaphysics, e.g., that God exists, that our mind is a distinct substance from our body, the initial premise that we know the claims is less than compelling. Taken with regard to other areas, however, the argument clearly has legs. We know a great deal of mathematics, and what we know, we know to be necessarily true. None of our experiences warrants a belief in such necessity, and we do not seem to base our knowledge on any experiences. The warrant that provides us with knowledge arises from an intellectual grasp of the propositions which is clearly part of our learning. Similarly, we seem to have such moral knowledge as that, all other things being equal, it is wrong to break a promise and that pleasure is intrinsically good. No empirical lesson about how things are can warrant such knowledge of how they ought to be.

This argument for the Intuition/Deduction thesis raises additional questions which rationalists must answer. Insofar as they maintain that our knowledge of necessary truths in mathematics or elsewhere by intuition and deduction is substantive knowledge of the external world, they owe us an account of this form of necessity. Many empiricists stand ready to argue that “necessity resides in the way we talk about things, not in the things we talk about” (Quine 1966, p. 174). Similarly, if rationalists claim that our knowledge in morals is knowledge of an objective form of obligation, they owe us an account of how objective values are part of a world of apparently valueless facts.

Perhaps most of all, any defenders of the Intuition/Deduction thesis owe us an account of what intuition is and how it provides warranted true beliefs about the external world. What is it to intuit a proposition and how does that act of intuition support a warranted belief? Their argument presents intuition and deduction as an explanation of assumed knowledge that can’t—they say—be explained by experience, but such an explanation by intuition and deduction requires that we have a clear understanding of intuition and how it supports warranted beliefs. Metaphorical characterizations of intuition as intellectual “grasping” or “seeing” are not enough, and if intuition is some form of intellectual “grasping,” it appears that all that is grasped is relations among our concepts, rather than facts about the external world, as the empiricists defenders of intuition and deduction argue. One current approach to the issue involves an appeal to Phenomenal Conservatism (Huemer 2001), the principle that if it seems to one as if something is the case, then one is prima facie justified in believing that it is so. Intuitions are then taken to be a particular sort of seeming or appearance: “[A]n intuition that p is a state of its seeming to one that p that is not dependent on inference from other beliefs and that results from thinking about p, as opposed to perceiving, remembering, or introspecting” (Huemer 2005, p. 102). Just as it can visually seem or appear to one as if there’s a tree outside the window, it can intellectually seem or appear to one as if nothing can be both entirely red and entirely green. This approach aims to demystify intuitions; they are but one more form of seeming-state along with ones we gain from sense perception, memory, and introspection. It does not, however, tell us all we need to know. Any intellectual faculty, whether it be sense perception, memory, introspection or intuition, provides us with warranted beliefs only if it is generally reliable. The reliability of sense perception stems from the causal connection between how external objects are and how we experience them. What accounts for the reliability of our intuitions regarding the external world? Is our intuition of a particular true proposition the outcome of some causal interaction between ourselves and some aspect of the world? What aspect? What is the nature of this causal interaction? That the number three is prime does not appear to cause anything, let alone our intuition that it is prime. As Michael Huemer (2005, p. 123) points out in mounting his own defense of moral intuitionism, “The challenge for the moral realist, then, is to explain how it would be anything more than chance if my moral beliefs were true, given that I do not interact with moral properties.”

These issues are made all the more pressing by the classic empiricist response to the argument. The reply is generally credited to Hume and begins with a division of all true propositions into two categories.

All the objects of human reason or inquiry may naturally be divided into two kinds, to wit, “Relations of Ideas,” and “Matters of Fact.” Of the first are the sciences of Geometry, Algebra, and Arithmetic, and, in short, every affirmation which is either intuitively or demonstratively certain. That the square of the hypotenuse is equal to the square of the two sides is a proposition which expresses a relation between these figures. That three times five is equal to half of thirty expresses a relation between these numbers. Propositions of this kind are discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe. Though there never were a circle or triangle in nature, the truths demonstrated by Euclid would forever retain their certainty and evidence. Matters of fact, which are the second objects of human reason, are not ascertained in the same manner, nor is our evidence of their truth, however great, of a like nature with the foregoing. The contrary of every matter of fact is still possible, because it can never imply a contradiction and is conceived by the mind with the same facility and distinctness as if ever so conformable to reality. ( Enquiry , 4.1, p. 24)

Intuition and deduction can provide us with knowledge of necessary truths such as those found in mathematics and logic, but such knowledge is not substantive knowledge of the external world. It is only knowledge of the relations of our own ideas. If the rationalist shifts the argument so it appeals to knowledge in morals, Hume’s reply is to offer an analysis of our moral concepts by which such knowledge is empirically gained knowledge of matters of fact.

Morals and criticism are not so properly objects of the understanding as of taste and sentiment. Beauty, whether moral or natural, is felt more properly than perceived. Or if we reason concerning it and endeavor to fix the standard, we regard a new fact, to wit, the general taste of mankind, or some other fact which may be the object of reasoning and inquiry. ( Enquiry , 12.3, p. 122)

If the rationalist appeals to our knowledge in metaphysics to support the argument, Hume denies that we have such knowledge.

If we take in our hand any volume--of divinity or school metaphysics, for instance--let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames, for it can contain nothing but sophistry and illusion. ( Enquiry , 12.3, p. 123)

An updated version of this general empiricist reply, with an increased emphasis on language and the nature of meaning, is given in the twentieth-century by A. J. Ayer’s version of logical positivism. Adopting positivism’s verification theory of meaning, Ayer assigns every cognitively meaningful sentence to one of two categories: either it is a tautology, and so true solely by virtue of the meaning of its terms and provides no substantive information about the world, or it is open to empirical verification. There is, then, no room for knowledge about the external world by intuition or deduction.

There can be no a priori knowledge of reality. For … the truths of pure reason, the propositions which we know to be valid independently of all experience, are so only in virtue of their lack of factual content … [By contrast] empirical propositions are one and all hypotheses which may be confirmed or discredited in actual sense experience. (Ayer 1952, pp. 86; 93–94)

The rationalists’ argument for the Intuition/Deduction thesis goes wrong at the start, according to empiricists, by assuming that we can have substantive knowledge of the external world that outstrips what experience can warrant. We cannot.

This empiricist reply faces challenges of its own. Our knowledge of mathematics seems to be about something more than our own concepts. Our knowledge of moral judgments seems to concern not just how we feel or act but how we ought to behave. The general principles that provide a basis for the empiricist view, e.g. Hume’s overall account of our ideas, the Verification Principle of Meaning, are problematic in their own right.

In all, rationalists have an argument for the Intuition/Deduction thesis relative to our substantive knowledge of the external world, but its success rests on how well they can answer questions about the nature and epistemic force of intuition made all the more pressing by the classic empiricist reply.

The Innate Knowledge thesis asserts that we have a priori knowledge, that is knowledge independent, for its justification, of sense experience, as part of our rational nature. Experience may trigger our awareness of this knowledge, but it does not provide us with it. The knowledge is already there.

Plato presents an early version of the Innate Knowledge thesis in the Meno as the doctrine of knowledge by recollection. The doctrine is motivated in part by a paradox that arises when we attempt to explain the nature of inquiry. How do we gain knowledge of a theorem in geometry? We inquire into the matter. Yet, knowledge by inquiry seems impossible ( Meno , 80d-e). We either already know the theorem at the start of our investigation or we do not. If we already have the knowledge, there is no place for inquiry. If we lack the knowledge, we don’t know what we are seeking and cannot recognize it when we find it. Either way we cannot gain knowledge of the theorem by inquiry. Yet, we do know some theorems.

The doctrine of knowledge by recollection offers a solution. When we inquire into the truth of a theorem, we both do and do not already know it. We have knowledge in the form of a memory gained from our soul’s knowledge of the theorem prior to its union with our body. We also lack some knowledge because, in our soul’s unification with the body, it has forgotten the knowledge and now needs to recollect it. Thus, learning the theorem allows us, in effect, to recall what we already know.

Plato famously illustrates the doctrine with an exchange between Socrates and a young slave, in which Socrates guides the slave from ignorance to mathematical knowledge. The slave’s experiences, in the form of Socrates’ questions and illustrations, are the occasion for his recollection of what he learned previously. Plato’s metaphysics provides additional support for the Innate Knowledge Thesis. Since our knowledge is of abstract, eternal Forms, which clearly lie beyond our sensory experience, it is independent, for its justification, of experience.

Contemporary supporters of Plato’s position are scarce. The initial paradox, which Plato describes as a “trick argument” ( Meno , 80e), rings sophistical. The metaphysical assumptions in the solution need justification. The solution does not answer the basic question: Just how did the slave’s soul learn the theorem? The Intuition/Deduction thesis offers an equally, if not more, plausible account of how the slave gains this type of knowledge that is independent of experience. Nonetheless, Plato’s position illustrates the kind of reasoning that has caused many philosophers to adopt some form of the Innate Knowledge thesis. We are confident that we know certain propositions about the external world, but there seems to be no adequate explanation of how we gained this knowledge short of saying that it is innate. Its content is beyond what we directly gain in experience, as well as what we can gain by performing mental operations on what experience provides. It does not seem to be based on an intuition or deduction. That it is innate in us appears to be the best explanation.

Noam Chomsky argues along similar lines in presenting what he describes as a “rationalist conception of the nature of language” (1975, p. 129). Chomsky argues that the experiences available to language learners are far too sparse to account for their knowledge of their language. To explain language acquisition, we must assume that learners have an innate knowledge of a universal grammar capturing the common deep structure of natural languages. It is important to note that Chomsky’s language learners do not know particular propositions describing a universal grammar. They have a set of innate capacities or dispositions which enable and determine their language development. Chomsky gives us a theory of innate learning capacities or structures rather than a theory of innate knowledge. His view does not support the Innate Knowledge thesis as rationalists have traditionally understood it. As one commentator puts it, “Chomsky’s principles … are innate neither in the sense that we are explicitly aware of them, nor in the sense that we have a disposition to recognize their truth as obvious under appropriate circumstances. And hence it is by no means clear that Chomsky is correct in seeing his theory as following the traditional rationalist account of the acquisition of knowledge” (Cottingham 1984, p. 124). Indeed, such a theory, which places nativism at the level of mental capacities or structures enabling us to acquire certain types of knowledge rather than at the level of knowledge we already posses, is akin to an empiricist take on the issue. Locke and Reid, for instance, believe that the human mind is endowed with certain abilities that, when developed in the usual course of nature, will lead us to acquire useful knowledge of the external world. The main idea is that it is part of our biology to have a digestive system that, when fed the right kind of food, allows us to process the required nutrients to enable us to continue to live for a while. Similarly, it is part of our biology to have a mental architecture that, when fed the right kind of information and experiences, allows us to process that information and transform it into knowledge. The knowledge itself is no more innate than the processed nutrients are. On a view like this, no knowledge is innate; however, we are born with certain capabilities and disposition that enable us to acquire knowledge, just as we are equipped with certain organs that allow our bodies to function well while we’re alive.

Peter Carruthers (1992) argues that we have innate knowledge of the principles of folk-psychology. Folk-psychology is a network of common-sense generalizations that hold independently of context or culture and concern the relationships of mental states to one another, to the environment and states of the body and to behavior (1992, p. 115). It includes such beliefs as that pains tend to be caused by injury, that pains tend to prevent us from concentrating on tasks, and that perceptions are generally caused by the appropriate state of the environment. Carruthers notes the complexity of folk-psychology, along with its success in explaining our behavior and the fact that its explanations appeal to such unobservables as beliefs, desires, feelings, and thoughts. He argues that the complexity, universality, and depth of folk-psychological principles outstrips what experience can provide, especially to young children who by their fifth year already know a great many of them. This knowledge is also not the result of intuition or deduction; folk-psychological generalizations are not seen to be true in an act of intellectual insight. Carruthers concludes, “[The problem] concerning the child’s acquisition of psychological generalizations cannot be solved, unless we suppose that much of folk-psychology is already innate, triggered locally by the child’s experience of itself and others, rather than learned” (1992, p. 121).

Empiricists, and some rationalists, attack the Innate Knowledge thesis in two main ways. First, they offer accounts of how sense experience or intuition and deduction provide the knowledge that is claimed to be innate. Second, they directly criticize the Innate Knowledge thesis itself. The classic statement of this second line of attack is presented in Locke’s Essay . Locke raises the issue of just what innate knowledge is. Particular instances of knowledge are supposed to be in our minds as part of our rational make-up, but how are they “in our minds”? If the implication is that we all consciously have this knowledge, it is plainly false. Propositions often given as examples of innate knowledge, even such plausible candidates as the principle that the same thing cannot both be and not be, are not consciously accepted by children and those with severe cognitive limitations. If the point of calling such principles “innate” is not to imply that they are or have been consciously accepted by all rational beings, then it is hard to see what the point is. “No proposition can be said to be in the mind, which it never yet knew, which it never yet was conscious of” ( Essay , 1.2.5). Proponents of innate knowledge might respond that some knowledge is innate in that we have the capacity to have it. That claim, while true, is of little interest, however. “If the capacity of knowing, be the natural impression contended for, all the truths a man ever comes to know, will, by this account, be every one of them, innate; and this great point will amount to no more, but only an improper way of speaking; which whilst it pretends to assert the contrary, says nothing different from those, who deny innate principles. For nobody, I think, ever denied, that the mind was capable of knowing several truths” ( Essay , 1.2.5). Locke thus challenges defenders of the Innate Knowledge thesis to present an account of innate knowledge that allows their position to be both true and interesting. A narrow interpretation of innateness faces counterexamples of rational individuals who do not meet its conditions. A generous interpretation implies that all our knowledge, even that clearly provided by experience, is innate.

Defenders of innate knowledge take up Locke’s challenge. Leibniz responds in New Essays by appealing to an account of innateness in terms of natural potential to avoid Locke’s dilemma. Consider Peter Carruthers’ similar reply.

We have noted that while one form of nativism claims (somewhat implausibly) that knowledge is innate in the sense of being present as such (or at least in propositional form) from birth, it might also be maintained that knowledge is innate in the sense of being innately determined to make its appearance at some stage in childhood. This latter thesis is surely the most plausible version of nativism. (1992, p. 51)

Carruthers claims that our innate knowledge is determined through evolutionary selection (p. 111). Evolution has resulted in our being determined to know certain things (e.g. principles of folk-psychology) at particular stages of our life, as part of our natural development. Experiences provide the occasion for our consciously believing the known propositions but not the basis for our knowledge of them (p. 52). Carruthers thus has a ready reply to Locke’s counterexamples of children and cognitively limited persons who do not believe propositions claimed to be instances of innate knowledge. The former have not yet reached the proper stage of development; the latter are persons in whom natural development has broken down (pp. 49–50).

A serious problem for the Innate Knowledge thesis remains, however. We know a proposition only if it is true, we believe it and our belief is warranted. Rationalists who assert the existence of innate knowledge are not just claiming that, as a matter of human evolution, God’s design or some other factor, at a particular point in our development, certain sorts of experiences trigger our belief in particular propositions in a way that does not involve our learning them from the experiences. Their claim is even bolder: In at least some of these cases, our empirically triggered, but not empirically warranted, belief is nonetheless warranted and so known. How can these beliefs be warranted if they do not gain their warrant from the experiences that cause us to have them or from intuition and deduction?

Some rationalists think that a reliabilist account of warrant provides the answer. According to Reliabilism, beliefs are warranted if they are formed by a process that generally produces true beliefs rather than false ones. The true beliefs that constitute our innate knowledge are warranted, then, because they are formed as the result of a reliable belief-forming process. Carruthers maintains that “Innate beliefs will count as known provided that the process through which they come to be innate is a reliable one (provided, that is, that the process tends to generate beliefs that are true)” (1992, p. 77). He argues that natural selection results in the formation of some beliefs and is a truth-reliable process.

An appeal to Reliabilism, or a similar causal theory of warrant, may well be the best way to develop the Innate Knowledge thesis. Even so, some difficulties remain. First, reliabilist accounts of warrant are themselves quite controversial. Second, rationalists must give an account of innate knowledge that maintains and explains the distinction between innate knowledge and non-innate knowledge, and it is not clear that they will be able to do so within such an account of warrant. Suppose for the sake of argument that we have innate knowledge of some proposition, P . What makes our knowledge that P innate? To sharpen the question, what difference between our knowledge that P and a clear case of non-innate knowledge, say our knowledge that something is red based on our current visual experience of a red table, makes the former innate and the latter not innate? In each case, we have a true, warranted belief. In each case, presumably, our belief gains its warrant from the fact that it meets a particular causal condition, e.g., it is produced by a reliable process. In each case, the causal process is one in which an experience causes us to believe the proposition at hand (that P ; that something is red), for, as defenders of innate knowledge admit, our belief that P is “triggered” by an experience, as is our belief that something is red. The insight behind the Innate Knowledge thesis seems to be that the difference between our innate and non-innate knowledge lies in the relation between our experience and our belief in each case. The experience that causes our belief that P does not “contain” the information that P , while our visual experience of a red table does “contain” the information that something is red. Yet, exactly what is the nature of this containment relation between our experiences, on the one hand, and what we believe, on the other, that is missing in the one case but present in the other? The nature of the experience-belief relation seems quite similar in each. The causal relation between the experience that triggers our belief that P and our belief that P is contingent, as is the fact that the belief-forming process is reliable. The same is true of our experience of a red table and our belief that something is red. The causal relation between the experience and our belief is again contingent. We might have been so constructed that the experience we describe as “being appeared to redly” caused us to believe, not that something is red, but that something is hot. The process that takes us from the experience to our belief is also only contingently reliable. Moreover, if our experience of a red table “contains” the information that something is red, then that fact, not the existence of a reliable belief-forming process between the two, should be the reason why the experience warrants our belief. By appealing to Reliabilism, or some other causal theory of warrant, rationalists may obtain a way to explain how innate knowledge can be warranted. They still need to show how their explanation supports an account of the difference between innate knowledge and non-innate knowledge. So, Locke's criticism -- that there is no true distinction between innate versus non-innate knowledge that rationalists may draw -- still stands, in the face of the best rationalist defense of the Innate Knowledge thesis.

According to the Innate Concept thesis, some of our concepts have not been gained from experience. They are instead part of our rational make-up, and experience simply triggers a process by which we consciously grasp them. The main concern motivating the rationalist should be familiar by now: the content of some concepts seems to outstrip anything we could have gained from experience. An example of this reasoning is presented by Descartes in the Meditations . Although he sometimes seems committed to the view that all our ideas are innate (Adams 1975 and Gotham 2002), he there classifies our ideas as adventitious, invented by us, and innate. Adventitious ideas, such as a sensation of heat, are gained directly through sense experience. Ideas invented by us, such as our idea of a hippogriff, are created by us from other ideas we possess. Innate ideas, such as our ideas of God, of extended matter, of substance, and of a perfect triangle, are placed in our minds by God at creation. Consider Descartes’s argument that our concept of God, as an infinitely perfect being, is innate. Our concept of God is not directly gained in experience, as particular tastes, sensations, and mental images might be. Its content is beyond what we could ever construct by applying available mental operations to what experience directly provides. From experience, we can gain the concept of a being with finite amounts of various perfections, one, for example, that is finitely knowledgeable, powerful and good. We cannot however move from these empirical concepts to the concept of a being of infinite perfection. (“I must not think that, just as my conceptions of rest and darkness are arrived at by negating movement and light, so my perception of the infinite is arrived at not by means of a true idea but by merely negating the finite,” Third Meditation, p. 94.) Descartes supplements this argument by another. Not only is the content of our concept of God beyond what experience can provide, the concept is a prerequisite for our employment of the concept of finite perfection gained from experience. (“My perception of the infinite, that is God, is in some way prior to my perception of the finite, that is myself. For how could I understand that I doubted or desired—that is lacked something—and that I was not wholly perfect, unless there were in me some idea of a more perfect being which enabled me to recognize my own defects by comparison,” Third Meditation, p. 94).

An empiricist response to this general line of argument is given by Locke ( Essay , 1.4.1–25). First, there is the problem of explaining what it is for someone to have an innate concept. If having an innate concept entails consciously entertaining it at present or in the past, then Descartes’s position is open to obvious counterexamples. Young children and people from other cultures do not consciously entertain the concept of God and have not done so. Second, there is the objection that we have no need to appeal to innate concepts in the first place. Contrary to Descartes’s argument, we can explain how experience provides all our ideas, including those the rationalists take to be innate, and with just the content that the rationalists attribute to them.

Leibniz’s New Essays offers a rationalist reply to the first concern. Where Locke puts forth the image of the mind as a blank slate on which experience writes, Leibniz offers us the image of a block of marble, the veins of which determine what sculpted figures it will accept ( New Essays , Preface, p. 153). Leibniz’s metaphor contains an insight that Locke misses. The mind plays a role in determining the nature of its contents. This point does not, however, require the adoption of the Innate Concept thesis. Locke might still point out that we are not required to have the concepts themselves and the ability to use them, innately. In contemporary terms, what we are required to have is the right hardware that allows for the optimal running of the actual software. For Locke, there are no constrains here; for Leibniz, only a particular type of software is, indeed, able to be supported by the extant hardware. Put differently, the hardware itself determines what software can be optimally run, for a Leibnizian.

Rationalists have responded to the second part of the empiricist attack on the Innate Concept thesis—the empiricists’ claim that the thesis is without basis, as all our ideas can be explained as derived from experience—by focusing on difficulties in the empiricists’ attempts to give such an explanation. The difficulties are illustrated by Locke’s account. According to Locke, experience consists in external sensation and inner reflection. All our ideas are either simple or complex, with the former being received by us passively in sensation or reflection and the latter being built by the mind from simple materials through various mental operations. Right at the start, the account of how simple ideas are gained is open to an obvious counterexample acknowledged, but then set aside, by Hume in presenting his own empiricist theory. Consider the mental image of a particular shade of blue. If Locke is right, the idea is a simple one and should be passively received by the mind through experience. Hume points out otherwise:

Suppose therefore a person to have enjoyed his sight for thirty years and to have become perfectly acquainted with colors of all kinds, except one particular shade of blue, for instance, which it never has been his fortune to meet with; let all the different shades of that color, except that single one, be placed before him, descending gradually from the deepest to the lightest, it is plain that he will perceive a blank where that shade is wanting and will be sensible that there is a greater distance in that place between the contiguous colors than in any other. Now I ask whether it be possible for him, from his own imagination, to supply this deficiency and raise up to himself the idea of that particular shade, though it had never been conveyed to him by his senses? I believe there are but few will be of the opinion that he can… ( Enquiry , 2, pp. 15–16)

Even when it comes to such simple ideas as the image of a particular shade of blue, the mind seems to be more than a blank slate on which experience writes. The main question is whether the veins in Leibniz’s metaphor should count as part of the knowledge or just as part of our biological mental architecture: all the knowledge we can ever acquire is constrained by the type of beings we are. This does not require our positing that concepts be part of the inner workings, at the beginning of our lives.

On the other hand, consider, too, our concept of a particular color, say red. Critics of Locke’s account have pointed out the weaknesses in his explanation of how we gain such a concept by the mental operation of abstraction on individual cases. For one thing, it makes the incorrect assumption that various instances of a particular concept share a common feature. Carruthers puts the objection as follows:

In fact problems arise for empiricists even in connection with the very simplest concepts, such as those of colour. For it is false that all instances of a given colour share some common feature. In which case we cannot acquire the concept of that colour by abstracting the common feature of our experience. Thus consider the concept red . Do all shades of red have something in common? If so, what? It is surely false that individual shades of red consist, as it were, of two distinguishable elements a general redness together with a particular shade. Rather, redness consists in a continuous range of shades, each of which is only just distinguishable from its neighbors. Acquiring the concept red is a matter of learning the extent of the range. (1992, p. 59)

For another thing, Locke’s account of concept acquisition from particular experiences seems circular: “For noticing or attending to a common feature of various things presupposes that you already possess the concept of the feature in question.” (Carruthers 1992, p. 55)

Consider in this regard Locke’s account of how we gain our concept of causation.

In the notice that our senses take of the constant vicissitude of things, we cannot but observe, that several particulars, both qualities and substances; begin to exist; and that they receive this their existence from the due application and operation of some other being. From this observation, we get our ideas of cause and effect. ( Essay , 2.26.1)

We get our concept of causation from our observation that some things receive their existence from the application and operation of some other things. Yet, to be able to make this observation, we must have our minds primed to do so. Rationalists argue that we cannot make this observation unless we already have the concept of causation. Empiricists, on the other hand, argue that our minds are constituted in a certain way, so that we can gain our ideas of causation and of power in a non-circular manner.

Rationalists would argue that Locke’s account of how we gain our idea of power displays a similar circularity.

The mind being every day informed, by the senses, of the alteration of those simple ideas, it observes in things without; and taking notice how one comes to an end, and ceases to be, and another begins to exist which was not before; reflecting also on what passes within itself, and observing a constant change of its ideas, sometimes by the impression of outward objects on the senses, and sometimes by the determination of its own choice; and concluding from what it has so constantly observed to have been, that the like changes will for the future be made in the same things, by like agents, and by the like ways, considers in one thing the possibility of having any of its simple ideas changed, and in another the possibility of making that change; and so comes by that idea which we call power. ( Essay , 2.21.1)

We come by the idea of power though considering the possibility of changes in our ideas made by experiences and our own choices. Yet, to consider this possibility—of some things making a change in others—we must already have a concept of power, rationalists would say. Empiricists, on the other hand, would point out, again, that what we actually need is for our minds to be able to recognize this, by having the correct abilities and faculties. Just as we don’t need to have a concept telling us how it is that we have binocular vision, being able to recognize change would be cashed out by us having the requisite faculty enabling us to do so.

Another way to meet at least some of these challenges to an empiricist account of the origin of our concepts is to revise our understanding of the content of our concepts so as to bring them more in line with what experience will clearly provide. Hume famously takes this approach. Beginning in a way reminiscent of Locke, he distinguishes between two forms of mental contents or “perceptions,” as he calls them: impressions and ideas. Impressions are the contents of our current experiences: our sensations, feelings, emotions, desires, and so on. Ideas are mental contents derived from impressions. Simple ideas are copies of impressions; complex ideas are derived from impressions by “compounding, transposing, augmenting or diminishing” them. Given that all our ideas are thus gained from experience, Hume offers us the following method for determining the content of any idea and thereby the meaning of any term taken to express it.

When we entertain, therefore, any suspicion that a philosophical term is employed without any meaning or idea (as is but too frequent), we need but inquire from what impression is that supposed idea derived ? And if it be impossible to assign any, this will confirm our suspicion. ( Enquiry , 2, p. 16)

Using this test, Hume draws out one of the most important implications of the empiricists’ denial of the Innate Concept thesis. If experience is indeed the source of all ideas, then our experiences also determine the content of our ideas. Our ideas of causation, of substance, of right and wrong have their content determined by the experiences that provide them. Those experiences, Hume argues, are unable to support the content that many rationalists and some empiricists, such as Locke, attribute to the corresponding ideas. Our inability to explain how some concepts, with the contents the rationalists attribute to them, are gained from experience should not lead us to adopt the Innate Concept thesis. It should lead us to accept a more limited view of the contents for those concepts, and thereby a more limited view of our ability to describe and understand the world.

Consider, for example, our idea of causation. Descartes takes it to be innate. Hume’s empiricist account severely limits its content. Our idea of causation is derived from a feeling of expectation rooted in our experiences of the constant conjunction of similar causes and effects.

It appears, then, that this idea of a necessary connection among events arises from a number of similar instances which occur, of the constant conjunction of these events; nor can that idea ever be suggested by any one of these instances surveyed in all possible lights and positions. But there is nothing in a number of instances, different from every single instance, which is supposed to be exactly similar, except only that after a repetition of similar instances the mind is carried by habit, upon the appearance of one event, to expect its usual attendant and to believe that it will exist. This connection, therefore, which we feel in the mind, this customary transition of the imagination from one object to its usual attendant, is the sentiment or impression from which we form the idea of power or necessary connection. ( Enquiry , 7.2, p. 59)

The source of our idea in experience determines its content.

Suitably to this experience, therefore, we may define a cause to be an object followed by another, and where all the objects, similar to the first are followed by objects similar to the second… We may, therefore, suitably to this experience, form another definition of cause and call it an object followed by another, and whose appearance always conveys the thought of the other . ( Enquiry , 7.2, p. 60)

Our claims, and any knowledge we may have, about causal connections in the world turn out, given the limited content of our empirically based concept of causation, to be claims and knowledge about the constant conjunction of events and our own feelings of expectation. Thus, the initial disagreement between rationalists and empiricists about the source of our ideas leads to one about their content and thereby the content of our descriptions and knowledge of the world.

Like philosophical debates generally, the rationalist/empiricist debate ultimately concerns our position in the world, in this case our position as rational inquirers. To what extent do our faculties of reason and experience support our attempts to know and understand our situation?

  • Adams, R., 1975, “Where Do Our Ideas Come From? Descartes vs Locke”, reprinted in Stitch S. (ed.) Innate Ideas , Berkeley, CA: California University Press.
  • Alexander, J. and Weinberg, J., 2007, “Analytic Epistemology and Experimental Philosophy,” Philosophy Compass , 2(1): 56–80.
  • Aune, B., 1970, Rationalism, Empiricism and Pragmatism: An Introduction , New York: Random House.
  • Ayer, A. J., 1952, Language, Truth and Logic , New York: Dover Publications.
  • Bealer, G., 1999, “A Theory of the A priori ,” Noûs , 33: 29–55.
  • Bealer, G. and Strawson, P. F., 1992, “The Incoherence of Empiricism,” Proceedings of the Aristotelian Society (Supplementary Volume), 66: 99–143.
  • Boyle, D., 2009, Descartes on Innate Ideas , London: Continuum.
  • Bonjour, L., 1998, In Defense of Pure Reason , Cambridge: Cambridge University Press.
  • Block, N., 1981, Essays in Philosophy of Psychology (Volume II), London: Methuen, Part Four.
  • Carruthers, P., 1992, Human Knowledge and Human Nature , Oxford: Oxford University Press.
  • Casullo, A., 2003, A priori Knowledge and Justification , New York: Oxford University Press.
  • Casullo, A. (ed.), 2012, Essays on A priori Knowledge and Justification , New York: Oxford University Press.
  • Clarke, D., 1982, Descartes’ Philosophy of Science , Manchester: Manchester University Press.
  • Cottingham, J., 1984, Rationalism , London: Paladin Books.
  • Chomsky, N., 1975, “Recent Contributions to the Theory of Innate Ideas”, reprinted in S. Stitch (ed.), Innate Ideas , Berkeley, CA: California University Press.
  • –––, 1988, Language and Problems of Knowledge , Cambridge, MA: MIT Press.
  • De Paul, M. and W. Ramsey (eds.), 1998, Rethinking Intuition: The Psychology of Intuition and Its Role in Philosophical Inquiry , Lanham, MD: Rowman and Littlefield.
  • De Rosa, R., 2004, “Locke’s Essay, Book I: The Question-Begging Status of the Anti-Nativist Arguments”, Philosophy and Phenomenological Research , 69: 37–64.
  • –––, 2000, “On Fodor’s Claim That Classical Empiricists and Rationalists Agree on the Innateness of Ideas”, ProtoSociology , 14: 240–269.
  • Descartes, R., 1628, Rules for the Direction of our Native Intelligence , in Descartes: Selected Philosophical Writings , John Cottingham, Robert Stoothoff and Dugald Murdoch (trans.), Cambridge: Cambridge University Press, 1988 [abbreviated as Rules ].
  • –––, 1641, Meditations , in Descartes: Selected Philosophical Writings , John Cottingham, Robert Stoothoff and Dugald Murdoch (trans.), Cambridge: Cambridge University Press, 1988 [abbreviated as Meditations ].
  • –––, 1644, Principles of Philosophy , in Descartes: Selected Philosophical Writings , John Cottingham, Robert Stoothoff and Dugald Murdoch (trans.), Cambridge: Cambridge University Press, 1988.
  • Falkenstein, L, 2004, “Nativism and the Nature of Thought in Reid’s Account of Our Knowledge of the External World”, in Terence Cuneo and Rene Van Woudenberg (eds.), The Cambridge Companion to Reid , Cambridge: Cambridge University Press, pp. 156–179.
  • Fodor, J., 1975, The Language of Thought , Cambridge, MA: Harvard University Press.
  • –––, 1981, Representations , Brighton: Harvester.
  • Gorham, G., 2002, “Descartes on the Innateness of All Ideas,” Canadian Journal of Philosophy , 32(3): 355–388.
  • Huemer, M., 2001, Skepticism and the Veil of Perception , Lanham, Maryland: Rowman and Littlefield.
  • –––, 2005, Ethical Intuitionism , Hampshire: Palgrave MacMillan.
  • Hume, D., 1739–40, A Treatise of Human Nature , ed. David Fate Norton and Mary J. Norton, The Clarendon Edition of the Works of David Hume, Oxford: Oxford University Press, 2011 [abbreviated as Treatise ].
  • –––, 1748, An Enquiry Concerning Human Understanding , ed. Tom L. Beauchamp, The Clarendon Edition of the Works of David Hume, Oxford: Oxford University Press, 2000 [abbreviated as Enquiry ].
  • Kant, I., 1783, Prolegomena to Any Future Metaphysic , Jonathan Bennett (trans.), PDF available online at Early Modern Texts [abbreviated as Prolegomena ].
  • Kenny, A., 1986, Rationalism, Empiricism and Idealism , Oxford: Oxford University Press.
  • Kripke, S., 1980, Naming and Necessity , Oxford: Blackwell.
  • Leibniz, G., c1704, New Essays on Human Understanding , in Leibniz: Philosophical Writings , G.H.R. Parkinson (ed.), Mary Morris and G.H.R. Parkinson (trans.), London: J.M. Dent & Sons, 1973 [abbreviated as New Essays ].
  • Locke, J., 1690, An Essay on Human Understanding , ed. Peter H. Nidditch, 1975 [abbreviated as Essay ].
  • Loeb, L., 1981, From Descartes to Hume: Continental Metaphysics and the Development of Modern Philosophy , Ithaca, NY: Cornell University Press.
  • Mackie, J. L., 1977, Ethics: Inventing Right and Wrong , London: Penguin Books.
  • Nadler, S., 2006, “The Doctrine of Ideas”, in S. Gaukroger (ed.), The Blackwell Guide to Descartes’ Meditations , Oxford: Blackwell Publishing.
  • Plato, Meno , W. K. C. Guthrie (trans.), Plato: Collected Dialogues , edited by Edith Hamilton and Huntington Cairns, Princeton: Princeton University Press, 1973.
  • Quine, W. V. O., 1966, Ways of Paradox and Other Essays , New York: Random House.
  • –––, 1951, “Two Dogmas of Empiricism,” in W.V.O. Quine, From a Logical Point of View , Cambridge, MA: Harvard University Press, 1951.
  • Reid, T., 1785, Essays on the Intellectual Powers of Man , ed. Derek Brookes and Knud Haakonssen, Edinburgh: Edinburgh University Press, 2002 [abbreviated as Intellectual Powers ].
  • Ross, W. D., 1930, The Right and the Good , Indianapolis, IN: Hackett Publishing, 1988.
  • Stitch, S., 1975, Innate Ideas , Berkeley, CA: California University Press.
  • Van Cleve, J., 2015, Problems from Reid , Oxford: Oxford University Press.
  • Weinberg, S, 2016, Consciousness in Locke , Oxford: Oxford University Press.
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.

[Please contact the author with suggestions.]

analytic/synthetic distinction | a priori justification and knowledge | Ayer, Alfred Jules | Berkeley, George | concepts | Descartes, René | Descartes, René: theory of ideas | epistemology | Hume, David | innate/acquired distinction | innateness: and language | innateness: historical controversies | justification, epistemic: foundationalist theories of | Kant, Immanuel | knowledge: analysis of | Leibniz, Gottfried Wilhelm | Locke, John | Plato | Quine, Willard Van Orman | reliabilist epistemology | skepticism | Spinoza, Baruch

Copyright © 2021 by Peter Markie M. Folescu < folescum @ missouri . edu >

  • 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

How to encourage and train students to think rationally

essay on rational thinking

We all like to think of ourselves as rational actors, but are we really? Much of what we do is guided by habit, emotion, and cognitive biases that encourage us to take mental shortcuts. For students, this can result in faulty conclusions and ineffective learning strategies. Thus, training students’ rational thinking skills — the ability to draw measured conclusions from data, rules, and logic — can have some very real benefits.

Promoting rational thinking can improve students’ problem-solving skills, making them more capable learners across subject areas. Competent rational thinkers have extra tools to help them focus and manage their emotions , benefits that extend well beyond the classroom. While there’s no one-quick-fix for developing skilled rational thinkers, there are some broad techniques you can use to help students cultivate these abilities over time.

Five techniques to encourage students to think rationally

1. welcome questions from students — no matter how big or small.

It might be obvious, but encouraging and welcoming student questions is an essential step towards making them better, clearer thinkers. Rational thinkers are those that take the time to think about things from different angles and explore gaps in knowledge where they find them. Impress upon students that there are no “stupid questions,” and create a space where it is safe for them to think aloud as they come up with new ideas or question existing ones.

Use tricky questions as an opportunity to find the answers together, either through discussion or research. While it’s not always possible to diverge from the lesson plan, student curiosity should be rewarded with time and attention as much as possible!

2. Focus on systematic problem-solving to train trail and error process

essay on rational thinking

One of the key principles of rational thinking is that many problems can be solved through thinking, with enough time and effort. The inverse of this is the binary attitude that students either know or don’t know how to do something (until they are shown).

Prompt students to work things out on their own through trial and error before testing their conclusions against those of their classmates. Remind students that making errors is an important part of the learning process, as it provides a chance for them to learn from their mistakes.

If you want to try this out in your classroom, consider assigning a Kialo Edu discussion as an essay alternative . Students can use the comment section to help their classmates sharpen their arguments through multiple rounds of peer feedback.

Rather than assigning a grade yourself, tell students they can choose their own grade once they are happy with their work. Activities like this encourage students to actively seek out constructive criticism as a way of strengthening their own ideas.

3. Allow students to explore the range of potential solutions to a problem

essay on rational thinking

Jonathan Baron, a notable philosopher on the subject of thinking, identifies “insufficient search” as a major obstacle to thinking effectively. 1 He deems this as the failure to consider more than one possible approach or answer to a given problem.

To train students to think “outside of the box,” give them lots of opportunities to tackle complex topics for which there are no easy — or singularly correct — answers. Open-ended classroom discussions on social and philosophical problems can stimulate this kind of thinking, which some studies have even linked to improvements across foundational skills like reading and math.

If you’re looking for ideas on where to start, Kialo Edu is designed to facilitate this type of wide-ranging discussion, with countless ideas in our library of debate topics to help spark inspiration.

Educators should also take steps to create a classroom culture where students can discuss their ideas freely and won’t feel personally attacked when those ideas are challenged. Emphasize that winning is not the goal of classroom debates, but rather learning something new together.

4. Talk about thinking with your students

For students to develop their rational faculties, they need to be aware of their own thinking. By being more aware, students can train themselves to recognize — and avoid — careless thinking. Reflective practices like learning journals prompt students to visualize how their understanding has progressed with practice and contribute to a growth mindset .

“Showing your work” is also universally applicable, whether students are tackling math problems or defending their position on an ethical question.

5. Practice what you teach by modeling rational thinking

It’s essential that educators model the kind of thinking practices they want students to develop. Be honest about the gaps in your knowledge when they come up, and be willing to change your mind when faced with new evidence. Students should learn that a sign of true intellectual strength is not having been right all along, but having the curiosity and perseverance to work towards the correct answer.

Here at Kialo Edu, we’re passionate about helping to build the next generation of accomplished rational thinkers. That’s why we designed our platform to encourage civil discourse, collaborative learning , and systematic thinking as students work together to build out the different aspects of a debate.

How do you teach your students to think rationally? If you have a technique that works, feel free to reach out and tell us about it on social media, or directly at [email protected]

Looking for more inspiration on how to teach critical thinking in your classroom? We’ve got lots of other resources!

  • Baron, J. (2006). Thinking and Deciding (4th ed., pp.6). Cambridge: Cambridge University Press. doi:10.1017/CBO9780511840265

Want to try Kialo Edu with your class?

Sign up for free and use Kialo Edu to have thoughtful classroom discussions and train students’ argumentation and critical thinking skills.


Supported by

In Praise of ‘Rationality’

  • Share full article

essay on rational thinking

  • Barnes and Noble
  • Books-A-Million

When you purchase an independently reviewed book through our site, we earn an affiliate commission.

By Anthony Gottlieb

  • Oct. 3, 2021

RATIONALITY What It Is, Why It Seems Scarce, Why It Matters By Steven Pinker

“Everything that runs has feet; the river runs; therefore the river has feet.” For more than half a millennium, starting in the 12th century, young men in Europe were routinely tortured with such puzzles. Their first college years were full of logic, mostly derived from Aristotle, who identified 14 main types of valid deduction and 13 key gambits of sophistical trickery. Such lessons were thought to do you good. One Oxford professor wrote in 1700 that they were more useful to a gentleman than learning to ride, dance or sing.

“Rationality: What It Is, Why It Seems Scarce, Why It Matters,” a new book by Steven Pinker, the Harvard psychologist, is in large part a primer on how to reason well. Similar guides for the general reader have been around for a while. John Locke wrote one over 300 years ago to help treat “miscarriages” of mortal reason. He conjectured that angels might lack our natural defects in logic, and thus have no need of books like his. In the 1800s, Jeremy Bentham, a social reformer, produced a guide to the tricks used in Britain’s Parliament, where the “give-the-dog-a-bad-name-and-hang-him argument” and the “eulogizing-lumping-classifier’s device” were supposedly rife. A list of over 30 less awkwardly named sophisms is in the most popular modern example of the genre, from the 1930s, “Straight and Crooked Thinking,” by Robert Thouless, which was reprinted as recently as 2011.

One difference between Pinker’s primer and these older works is that you’ll find more numbers in his. Probability and statistics now loom large in both straight and crooked thinking, but logic manuals generally offered only small bites of such fare. The main courses were usually a parade of fallacies, explained in words, plus formal deductive logic (which strips inferences to their skeletons, such as “Some A are B; therefore some B are A”). Pinker has now added comprehensive lessons on statistical significance, how to update your beliefs in the light of fresh data, how to calculate risks and rewards in decision-making and more. Graphics abound. To the logicians’ traditional Venn diagrams — illustrations that resemble bunches of party balloons — he adds bell curves and other graphs.

Plenty of this is unavoidably hard going. Formulas of conditional probability, in particular, may make some wistful for the torture of medieval syllogisms. Yet Pinker rightly treats the subject as valuable for clear thinking. Fumbling its application can, as he observes, lead to hypochondria and scaremongering — though a dose of math does not provide total protection against either. These lessons are taught well. Pinker’s jaunty demotic and occasional bar-stool sermons will not be to everyone’s taste, but the illustrative gags and cartoons are pedagogically apt. His deployment of perhaps the finest of Jewish sex jokes as a tool to explain the concept of “confounding variables” may deserve some sort of prize.

Pinker’s book does more than just lay out how we ought to reason. It also seeks to explain why our efforts often seem to fall short. Experimental psychology has had a lot to say on the matter in the past half-century or so, and news from the laboratory can make for grim reading. Even the simplest inferences seem to go awry for many people.

Psychologists have examined how their human guinea pigs grasp and use a basic form of valid inference known to logicians as modus tollens : “If P then Q. Not Q. Therefore not P.” It seems from experiments that about one-third of people don’t get it. And some studies find that most people think the following fallacious form of inference is logically valid: “If P then Q. Q. Therefore P.” Unkind logicians have dubbed this fallacy modus morons .

The best-known logic-defying experiment was first reported in 1981, by Amos Tversky, who died in 1996, and his colleague Daniel Kahneman, who was later awarded the Nobel in economic science for their work. In this experiment, you are given some background information about a fictitious woman, Linda, that makes it sound plausible that she is a feminist. You are then given several descriptions of her and asked to judge which are more likely to be true. They include: (1) “Linda is a bank teller”; (2) “Linda is a bank teller and is active in the feminist movement.” When groups of students were given this test, a large majority judged that (2) was more likely than (1). Yet according to the laws of probability, that answer makes no sense. It is like thinking you are more likely to be dealt the Queen of Hearts than you are to be dealt a Queen. One possibility is that in this context, some students took (1) to mean that Linda was a bank teller but not an active feminist. This would make their answer reasonable; but the morals to be drawn from the case are still contested.

Kahneman and Tversky dissected rationality with dozens of ingeniously designed tests, many of which asked people to choose between gambles with given probabilities and rewards. Their work, and that of others, led to the naming of over a hundred quirks and apparent biases. In economics, these experiments showed that our simple assumptions about what people want and what drives their decision-making are even more unrealistic than was thought. But what are the implications for logic? Are people hopelessly vulnerable to modus morons , or are these logic tests too artificial, and thus misleading? Pinker’s view, ably defended, is that our faculties work well in some settings but go wrong “when applied at scale, in novel circumstances, or in the service of other goals.”

Pinker devotes plenty of space to advocating rationality, which the authors of similar works have not found necessary to do, perhaps because anybody who chooses to read about rationality is probably already in favor of it. There is a “pandemic of poppycock,” he thinks, and more logic is needed. You might think it was impossible to exaggerate the popularity of ill-founded beliefs, but Pinker does manage it. For example, he cites a Gallup survey that found 42 percent of Americans believe in demonic possession. Yet Gallup itself rejected that result because it could not tell how many people took its question literally. Pinker also writes that “more than two billion people believe that if one doesn’t accept Jesus as one’s savior one will be damned to eternal torment in hell.” This bogus statistic includes every nominal Christian on the planet.

Like John Locke before him, Pinker wants more lessons in schools about reasoning and critical thinking. There is some evidence that such lessons work. But what part of the curriculum should be scaled back to make room for them? According to one analysis of Department of Education data, fewer than half of American adults are proficient at reading. And according to one Department of Health study, a third of adults have difficulty interpreting simple health information, such as the instructions on a drug label. Maybe it is wise to learn to walk before you learn to run.

Anthony Gottlieb’s most recent book is “The Dream of Enlightenment: The Rise of Modern Philosophy.”

RATIONALITY What It Is, Why It Seems Scarce, Why It Matters By Steven Pinker Illustrated. 408 pp. Viking. $32.

Explore More in Books

Want to know about the best books to read and the latest news start here..

James McBride’s novel sold a million copies, and he isn’t sure how he feels about that, as he considers the critical and commercial success  of “The Heaven & Earth Grocery Store.”

How did gender become a scary word? Judith Butler, the theorist who got us talking about the subject , has answers.

You never know what’s going to go wrong in these graphic novels, where Circus tigers, giant spiders, shifting borders and motherhood all threaten to end life as we know it .

When the author Tommy Orange received an impassioned email from a teacher in the Bronx, he dropped everything to visit the students  who inspired it.

Do you want to be a better reader?   Here’s some helpful advice to show you how to get the most out of your literary endeavor .

Each week, top authors and critics join the Book Review’s podcast to talk about the latest news in the literary world. Listen here .

Rational Thinking

  • Reference work entry
  • First Online: 01 January 2020
  • pp 4286–4288
  • Cite this reference work entry

Book cover

  • Nikki Blacksmith 3 , 4  

84 Accesses

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
  • Available as EPUB and PDF
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Epstein, S., Pacini, R., Denes-Raj, V., & Heier, H. (1996). Individual differences in intuitive-experiential and analytical-rational thinking styles. Journal of Personality and Social Psychology, 71 , 390–405.

Article   PubMed   Google Scholar  

Evans, J. S. B. T. (2008). Dual-processing accounts of reasoning, judgment, and social cognition. Annual Review of Psychology, 59 , 255–278.

Gigerenzer, G., & Goldstein, D. G. (1996). Reasoning the fast and frugal way: Models of bounded rationality. Psychological Review, 103 , 650–669.

Hamilton, K., Shih, S., & Mohammed, S. (2017). The predictive validity of the decision styles scale: An evaluation across task types. Personality and Individual Differences, 119 , 333–340.

Article   Google Scholar  

Marks, A. D. G., Hine, D. W., Blore, R. L., & Phillips, W. J. (2008). Assessing individual differences in adolescents’ preference for rational and experiential cognition. Personality and Individual Differences, 44 , 42–52.

Phillips, W. J., Fletcher, J. M., Marks, A. D. G., & Hine, D. W. (2016). Thinking styles and decision making: A meta-analysis. Psychological Bulletin, 142 , 260–290.

Reeve, C. L., & Bonaccio, S. (2011). The nature and structure of “intelligence.”. In T. Chamorro-Premuzic, A. Furnham, & S. von Stumm (Eds.), Handbook of individual differences (pp. 187–216). Oxford, England: Wiley-Blackwell.

Google Scholar  

Scott, S. G., & Bruce, R. A. (1995). Decision-making style: The development and assessment of a new measure. Educational and Psychological Measurement, 55 , 818–828.

Stanovich, K. E., & West, R. F. (1998). Individual differences in rational thought. Journal of Experimental Psychology: General, 127 , 161–188.

Stanovich, K. E., West, R. F., & Toplak, M. E. (2016). The rationality quotient: Toward a test of rational thinking . Cambridge, MA: The MIT Press.

Book   Google Scholar  

Download references

Author information

Authors and affiliations.

Foundational Science Research Unit, Consortium Research Fellows Program, Alexandria, VA, USA

Nikki Blacksmith

The George Washington University, Washington, DC, USA

You can also search for this author in PubMed   Google Scholar

Corresponding author

Correspondence to Nikki Blacksmith .

Editor information

Editors and affiliations.

Oakland University, Rochester, MI, USA

Virgil Zeigler-Hill

Todd K. Shackelford

Section Editor information

Department of Psychology, Wake Forest University, Winston-Salem, NC, USA

John F. Rauthmann

Rights and permissions

Reprints and permissions

Copyright information

© 2020 Springer Nature Switzerland AG

About this entry

Cite this entry.

Blacksmith, N. (2020). Rational Thinking. In: Zeigler-Hill, V., Shackelford, T.K. (eds) Encyclopedia of Personality and Individual Differences. Springer, Cham.

Download citation


Published : 22 April 2020

Publisher Name : Springer, Cham

Print ISBN : 978-3-319-24610-9

Online ISBN : 978-3-319-24612-3

eBook Packages : Behavioral Science and Psychology Reference Module Humanities and Social Sciences Reference Module Business, Economics and Social Sciences

Share this entry

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

  • Publish with us

Policies and ethics

  • Find a journal
  • Track your research
  • Search Menu
  • Browse content in Arts and Humanities
  • Browse content in Archaeology
  • Anglo-Saxon and Medieval Archaeology
  • Archaeological Methodology and Techniques
  • Archaeology by Region
  • Archaeology of Religion
  • Archaeology of Trade and Exchange
  • Biblical Archaeology
  • Contemporary and Public Archaeology
  • Environmental Archaeology
  • Historical Archaeology
  • History and Theory of Archaeology
  • Industrial Archaeology
  • Landscape Archaeology
  • Mortuary Archaeology
  • Prehistoric Archaeology
  • Underwater Archaeology
  • Urban Archaeology
  • Zooarchaeology
  • Browse content in Architecture
  • Architectural Structure and Design
  • History of Architecture
  • Residential and Domestic Buildings
  • Theory of Architecture
  • Browse content in Art
  • Art Subjects and Themes
  • History of Art
  • Industrial and Commercial Art
  • Theory of Art
  • Biographical Studies
  • Byzantine Studies
  • Browse content in Classical Studies
  • Classical History
  • Classical Philosophy
  • Classical Mythology
  • Classical Literature
  • Classical Reception
  • Classical Art and Architecture
  • Classical Oratory and Rhetoric
  • Greek and Roman Epigraphy
  • Greek and Roman Law
  • Greek and Roman Papyrology
  • Greek and Roman Archaeology
  • Late Antiquity
  • Religion in the Ancient World
  • Digital Humanities
  • Browse content in History
  • Colonialism and Imperialism
  • Diplomatic History
  • Environmental History
  • Genealogy, Heraldry, Names, and Honours
  • Genocide and Ethnic Cleansing
  • Historical Geography
  • History by Period
  • History of Emotions
  • History of Agriculture
  • History of Education
  • History of Gender and Sexuality
  • Industrial History
  • Intellectual History
  • International History
  • Labour History
  • Legal and Constitutional History
  • Local and Family History
  • Maritime History
  • Military History
  • National Liberation and Post-Colonialism
  • Oral History
  • Political History
  • Public History
  • Regional and National History
  • Revolutions and Rebellions
  • Slavery and Abolition of Slavery
  • Social and Cultural History
  • Theory, Methods, and Historiography
  • Urban History
  • World History
  • Browse content in Language Teaching and Learning
  • Language Learning (Specific Skills)
  • Language Teaching Theory and Methods
  • Browse content in Linguistics
  • Applied Linguistics
  • Cognitive Linguistics
  • Computational Linguistics
  • Forensic Linguistics
  • Grammar, Syntax and Morphology
  • Historical and Diachronic Linguistics
  • History of English
  • Language Acquisition
  • Language Evolution
  • Language Reference
  • Language Variation
  • Language Families
  • Lexicography
  • Linguistic Anthropology
  • Linguistic Theories
  • Linguistic Typology
  • Phonetics and Phonology
  • Psycholinguistics
  • Sociolinguistics
  • Translation and Interpretation
  • Writing Systems
  • Browse content in Literature
  • Bibliography
  • Children's Literature Studies
  • Literary Studies (Asian)
  • Literary Studies (European)
  • Literary Studies (Eco-criticism)
  • Literary Studies (Romanticism)
  • Literary Studies (American)
  • Literary Studies (Modernism)
  • Literary Studies - World
  • Literary Studies (1500 to 1800)
  • Literary Studies (19th Century)
  • Literary Studies (20th Century onwards)
  • Literary Studies (African American Literature)
  • Literary Studies (British and Irish)
  • Literary Studies (Early and Medieval)
  • Literary Studies (Fiction, Novelists, and Prose Writers)
  • Literary Studies (Gender Studies)
  • Literary Studies (Graphic Novels)
  • Literary Studies (History of the Book)
  • Literary Studies (Plays and Playwrights)
  • Literary Studies (Poetry and Poets)
  • Literary Studies (Postcolonial Literature)
  • Literary Studies (Queer Studies)
  • Literary Studies (Science Fiction)
  • Literary Studies (Travel Literature)
  • Literary Studies (War Literature)
  • Literary Studies (Women's Writing)
  • Literary Theory and Cultural Studies
  • Mythology and Folklore
  • Shakespeare Studies and Criticism
  • Browse content in Media Studies
  • Browse content in Music
  • Applied Music
  • Dance and Music
  • Ethics in Music
  • Ethnomusicology
  • Gender and Sexuality in Music
  • Medicine and Music
  • Music Cultures
  • Music and Religion
  • Music and Media
  • Music and Culture
  • Music Education and Pedagogy
  • Music Theory and Analysis
  • Musical Scores, Lyrics, and Libretti
  • Musical Structures, Styles, and Techniques
  • Musicology and Music History
  • Performance Practice and Studies
  • Race and Ethnicity in Music
  • Sound Studies
  • Browse content in Performing Arts
  • Browse content in Philosophy
  • Aesthetics and Philosophy of Art
  • Epistemology
  • Feminist Philosophy
  • History of Western Philosophy
  • Metaphysics
  • Moral Philosophy
  • Non-Western Philosophy
  • Philosophy of Science
  • Philosophy of Language
  • Philosophy of Mind
  • Philosophy of Perception
  • Philosophy of Action
  • Philosophy of Law
  • Philosophy of Religion
  • Philosophy of Mathematics and Logic
  • Practical Ethics
  • Social and Political Philosophy
  • Browse content in Religion
  • Biblical Studies
  • Christianity
  • East Asian Religions
  • History of Religion
  • Judaism and Jewish Studies
  • Qumran Studies
  • Religion and Education
  • Religion and Health
  • Religion and Politics
  • Religion and Science
  • Religion and Law
  • Religion and Art, Literature, and Music
  • Religious Studies
  • Browse content in Society and Culture
  • Cookery, Food, and Drink
  • Cultural Studies
  • Customs and Traditions
  • Ethical Issues and Debates
  • Hobbies, Games, Arts and Crafts
  • Lifestyle, Home, and Garden
  • Natural world, Country Life, and Pets
  • Popular Beliefs and Controversial Knowledge
  • Sports and Outdoor Recreation
  • Technology and Society
  • Travel and Holiday
  • Visual Culture
  • Browse content in Law
  • Arbitration
  • Browse content in Company and Commercial Law
  • Commercial Law
  • Company Law
  • Browse content in Comparative Law
  • Systems of Law
  • Competition Law
  • Browse content in Constitutional and Administrative Law
  • Government Powers
  • Judicial Review
  • Local Government Law
  • Military and Defence Law
  • Parliamentary and Legislative Practice
  • Construction Law
  • Contract Law
  • Browse content in Criminal Law
  • Criminal Procedure
  • Criminal Evidence Law
  • Sentencing and Punishment
  • Employment and Labour Law
  • Environment and Energy Law
  • Browse content in Financial Law
  • Banking Law
  • Insolvency Law
  • History of Law
  • Human Rights and Immigration
  • Intellectual Property Law
  • Browse content in International Law
  • Private International Law and Conflict of Laws
  • Public International Law
  • IT and Communications Law
  • Jurisprudence and Philosophy of Law
  • Law and Politics
  • Law and Society
  • Browse content in Legal System and Practice
  • Courts and Procedure
  • Legal Skills and Practice
  • Primary Sources of Law
  • Regulation of Legal Profession
  • Medical and Healthcare Law
  • Browse content in Policing
  • Criminal Investigation and Detection
  • Police and Security Services
  • Police Procedure and Law
  • Police Regional Planning
  • Browse content in Property Law
  • Personal Property Law
  • Study and Revision
  • Terrorism and National Security Law
  • Browse content in Trusts Law
  • Wills and Probate or Succession
  • Browse content in Medicine and Health
  • Browse content in Allied Health Professions
  • Arts Therapies
  • Clinical Science
  • Dietetics and Nutrition
  • Occupational Therapy
  • Operating Department Practice
  • Physiotherapy
  • Radiography
  • Speech and Language Therapy
  • Browse content in Anaesthetics
  • General Anaesthesia
  • Neuroanaesthesia
  • Browse content in Clinical Medicine
  • Acute Medicine
  • Cardiovascular Medicine
  • Clinical Genetics
  • Clinical Pharmacology and Therapeutics
  • Dermatology
  • Endocrinology and Diabetes
  • Gastroenterology
  • Genito-urinary Medicine
  • Geriatric Medicine
  • Infectious Diseases
  • Medical Toxicology
  • Medical Oncology
  • Pain Medicine
  • Palliative Medicine
  • Rehabilitation Medicine
  • Respiratory Medicine and Pulmonology
  • Rheumatology
  • Sleep Medicine
  • Sports and Exercise Medicine
  • Clinical Neuroscience
  • Community Medical Services
  • Critical Care
  • Emergency Medicine
  • Forensic Medicine
  • Haematology
  • History of Medicine
  • Browse content in Medical Dentistry
  • Oral and Maxillofacial Surgery
  • Paediatric Dentistry
  • Restorative Dentistry and Orthodontics
  • Surgical Dentistry
  • Browse content in Medical Skills
  • Clinical Skills
  • Communication Skills
  • Nursing Skills
  • Surgical Skills
  • Medical Ethics
  • Medical Statistics and Methodology
  • Browse content in Neurology
  • Clinical Neurophysiology
  • Neuropathology
  • Nursing Studies
  • Browse content in Obstetrics and Gynaecology
  • Gynaecology
  • Occupational Medicine
  • Ophthalmology
  • Otolaryngology (ENT)
  • Browse content in Paediatrics
  • Neonatology
  • Browse content in Pathology
  • Chemical Pathology
  • Clinical Cytogenetics and Molecular Genetics
  • Histopathology
  • Medical Microbiology and Virology
  • Patient Education and Information
  • Browse content in Pharmacology
  • Psychopharmacology
  • Browse content in Popular Health
  • Caring for Others
  • Complementary and Alternative Medicine
  • Self-help and Personal Development
  • Browse content in Preclinical Medicine
  • Cell Biology
  • Molecular Biology and Genetics
  • Reproduction, Growth and Development
  • Primary Care
  • Professional Development in Medicine
  • Browse content in Psychiatry
  • Addiction Medicine
  • Child and Adolescent Psychiatry
  • Forensic Psychiatry
  • Learning Disabilities
  • Old Age Psychiatry
  • Psychotherapy
  • Browse content in Public Health and Epidemiology
  • Epidemiology
  • Public Health
  • Browse content in Radiology
  • Clinical Radiology
  • Interventional Radiology
  • Nuclear Medicine
  • Radiation Oncology
  • Reproductive Medicine
  • Browse content in Surgery
  • Cardiothoracic Surgery
  • Gastro-intestinal and Colorectal Surgery
  • General Surgery
  • Neurosurgery
  • Paediatric Surgery
  • Peri-operative Care
  • Plastic and Reconstructive Surgery
  • Surgical Oncology
  • Transplant Surgery
  • Trauma and Orthopaedic Surgery
  • Vascular Surgery
  • Browse content in Science and Mathematics
  • Browse content in Biological Sciences
  • Aquatic Biology
  • Biochemistry
  • Bioinformatics and Computational Biology
  • Developmental Biology
  • Ecology and Conservation
  • Evolutionary Biology
  • Genetics and Genomics
  • Microbiology
  • Molecular and Cell Biology
  • Natural History
  • Plant Sciences and Forestry
  • Research Methods in Life Sciences
  • Structural Biology
  • Systems Biology
  • Zoology and Animal Sciences
  • Browse content in Chemistry
  • Analytical Chemistry
  • Computational Chemistry
  • Crystallography
  • Environmental Chemistry
  • Industrial Chemistry
  • Inorganic Chemistry
  • Materials Chemistry
  • Medicinal Chemistry
  • Mineralogy and Gems
  • Organic Chemistry
  • Physical Chemistry
  • Polymer Chemistry
  • Study and Communication Skills in Chemistry
  • Theoretical Chemistry
  • Browse content in Computer Science
  • Artificial Intelligence
  • Computer Architecture and Logic Design
  • Game Studies
  • Human-Computer Interaction
  • Mathematical Theory of Computation
  • Programming Languages
  • Software Engineering
  • Systems Analysis and Design
  • Virtual Reality
  • Browse content in Computing
  • Business Applications
  • Computer Security
  • Computer Games
  • Computer Networking and Communications
  • Digital Lifestyle
  • Graphical and Digital Media Applications
  • Operating Systems
  • Browse content in Earth Sciences and Geography
  • Atmospheric Sciences
  • Environmental Geography
  • Geology and the Lithosphere
  • Maps and Map-making
  • Meteorology and Climatology
  • Oceanography and Hydrology
  • Palaeontology
  • Physical Geography and Topography
  • Regional Geography
  • Soil Science
  • Urban Geography
  • Browse content in Engineering and Technology
  • Agriculture and Farming
  • Biological Engineering
  • Civil Engineering, Surveying, and Building
  • Electronics and Communications Engineering
  • Energy Technology
  • Engineering (General)
  • Environmental Science, Engineering, and Technology
  • History of Engineering and Technology
  • Mechanical Engineering and Materials
  • Technology of Industrial Chemistry
  • Transport Technology and Trades
  • Browse content in Environmental Science
  • Applied Ecology (Environmental Science)
  • Conservation of the Environment (Environmental Science)
  • Environmental Sustainability
  • Environmentalist Thought and Ideology (Environmental Science)
  • Management of Land and Natural Resources (Environmental Science)
  • Natural Disasters (Environmental Science)
  • Nuclear Issues (Environmental Science)
  • Pollution and Threats to the Environment (Environmental Science)
  • Social Impact of Environmental Issues (Environmental Science)
  • History of Science and Technology
  • Browse content in Materials Science
  • Ceramics and Glasses
  • Composite Materials
  • Metals, Alloying, and Corrosion
  • Nanotechnology
  • Browse content in Mathematics
  • Applied Mathematics
  • Biomathematics and Statistics
  • History of Mathematics
  • Mathematical Education
  • Mathematical Finance
  • Mathematical Analysis
  • Numerical and Computational Mathematics
  • Probability and Statistics
  • Pure Mathematics
  • Browse content in Neuroscience
  • Cognition and Behavioural Neuroscience
  • Development of the Nervous System
  • Disorders of the Nervous System
  • History of Neuroscience
  • Invertebrate Neurobiology
  • Molecular and Cellular Systems
  • Neuroendocrinology and Autonomic Nervous System
  • Neuroscientific Techniques
  • Sensory and Motor Systems
  • Browse content in Physics
  • Astronomy and Astrophysics
  • Atomic, Molecular, and Optical Physics
  • Biological and Medical Physics
  • Classical Mechanics
  • Computational Physics
  • Condensed Matter Physics
  • Electromagnetism, Optics, and Acoustics
  • History of Physics
  • Mathematical and Statistical Physics
  • Measurement Science
  • Nuclear Physics
  • Particles and Fields
  • Plasma Physics
  • Quantum Physics
  • Relativity and Gravitation
  • Semiconductor and Mesoscopic Physics
  • Browse content in Psychology
  • Affective Sciences
  • Clinical Psychology
  • Cognitive Psychology
  • Cognitive Neuroscience
  • Criminal and Forensic Psychology
  • Developmental Psychology
  • Educational Psychology
  • Evolutionary Psychology
  • Health Psychology
  • History and Systems in Psychology
  • Music Psychology
  • Neuropsychology
  • Organizational Psychology
  • Psychological Assessment and Testing
  • Psychology of Human-Technology Interaction
  • Psychology Professional Development and Training
  • Research Methods in Psychology
  • Social Psychology
  • Browse content in Social Sciences
  • Browse content in Anthropology
  • Anthropology of Religion
  • Human Evolution
  • Medical Anthropology
  • Physical Anthropology
  • Regional Anthropology
  • Social and Cultural Anthropology
  • Theory and Practice of Anthropology
  • Browse content in Business and Management
  • Business Strategy
  • Business Ethics
  • Business History
  • Business and Government
  • Business and Technology
  • Business and the Environment
  • Comparative Management
  • Corporate Governance
  • Corporate Social Responsibility
  • Entrepreneurship
  • Health Management
  • Human Resource Management
  • Industrial and Employment Relations
  • Industry Studies
  • Information and Communication Technologies
  • International Business
  • Knowledge Management
  • Management and Management Techniques
  • Operations Management
  • Organizational Theory and Behaviour
  • Pensions and Pension Management
  • Public and Nonprofit Management
  • Strategic Management
  • Supply Chain Management
  • Browse content in Criminology and Criminal Justice
  • Criminal Justice
  • Criminology
  • Forms of Crime
  • International and Comparative Criminology
  • Youth Violence and Juvenile Justice
  • Development Studies
  • Browse content in Economics
  • Agricultural, Environmental, and Natural Resource Economics
  • Asian Economics
  • Behavioural Finance
  • Behavioural Economics and Neuroeconomics
  • Econometrics and Mathematical Economics
  • Economic Systems
  • Economic History
  • Economic Methodology
  • Economic Development and Growth
  • Financial Markets
  • Financial Institutions and Services
  • General Economics and Teaching
  • Health, Education, and Welfare
  • History of Economic Thought
  • International Economics
  • Labour and Demographic Economics
  • Law and Economics
  • Macroeconomics and Monetary Economics
  • Microeconomics
  • Public Economics
  • Urban, Rural, and Regional Economics
  • Welfare Economics
  • Browse content in Education
  • Adult Education and Continuous Learning
  • Care and Counselling of Students
  • Early Childhood and Elementary Education
  • Educational Equipment and Technology
  • Educational Strategies and Policy
  • Higher and Further Education
  • Organization and Management of Education
  • Philosophy and Theory of Education
  • Schools Studies
  • Secondary Education
  • Teaching of a Specific Subject
  • Teaching of Specific Groups and Special Educational Needs
  • Teaching Skills and Techniques
  • Browse content in Environment
  • Applied Ecology (Social Science)
  • Climate Change
  • Conservation of the Environment (Social Science)
  • Environmentalist Thought and Ideology (Social Science)
  • Natural Disasters (Environment)
  • Social Impact of Environmental Issues (Social Science)
  • Browse content in Human Geography
  • Cultural Geography
  • Economic Geography
  • Political Geography
  • Browse content in Interdisciplinary Studies
  • Communication Studies
  • Museums, Libraries, and Information Sciences
  • Browse content in Politics
  • African Politics
  • Asian Politics
  • Chinese Politics
  • Comparative Politics
  • Conflict Politics
  • Elections and Electoral Studies
  • Environmental Politics
  • European Union
  • Foreign Policy
  • Gender and Politics
  • Human Rights and Politics
  • Indian Politics
  • International Relations
  • International Organization (Politics)
  • International Political Economy
  • Irish Politics
  • Latin American Politics
  • Middle Eastern Politics
  • Political Methodology
  • Political Communication
  • Political Philosophy
  • Political Sociology
  • Political Behaviour
  • Political Economy
  • Political Institutions
  • Political Theory
  • Politics and Law
  • Public Administration
  • Public Policy
  • Quantitative Political Methodology
  • Regional Political Studies
  • Russian Politics
  • Security Studies
  • State and Local Government
  • UK Politics
  • US Politics
  • Browse content in Regional and Area Studies
  • African Studies
  • Asian Studies
  • East Asian Studies
  • Japanese Studies
  • Latin American Studies
  • Middle Eastern Studies
  • Native American Studies
  • Scottish Studies
  • Browse content in Research and Information
  • Research Methods
  • Browse content in Social Work
  • Addictions and Substance Misuse
  • Adoption and Fostering
  • Care of the Elderly
  • Child and Adolescent Social Work
  • Couple and Family Social Work
  • Developmental and Physical Disabilities Social Work
  • Direct Practice and Clinical Social Work
  • Emergency Services
  • Human Behaviour and the Social Environment
  • International and Global Issues in Social Work
  • Mental and Behavioural Health
  • Social Justice and Human Rights
  • Social Policy and Advocacy
  • Social Work and Crime and Justice
  • Social Work Macro Practice
  • Social Work Practice Settings
  • Social Work Research and Evidence-based Practice
  • Welfare and Benefit Systems
  • Browse content in Sociology
  • Childhood Studies
  • Community Development
  • Comparative and Historical Sociology
  • Economic Sociology
  • Gender and Sexuality
  • Gerontology and Ageing
  • Health, Illness, and Medicine
  • Marriage and the Family
  • Migration Studies
  • Occupations, Professions, and Work
  • Organizations
  • Population and Demography
  • Race and Ethnicity
  • Social Theory
  • Social Movements and Social Change
  • Social Research and Statistics
  • Social Stratification, Inequality, and Mobility
  • Sociology of Religion
  • Sociology of Education
  • Sport and Leisure
  • Urban and Rural Studies
  • Browse content in Warfare and Defence
  • Defence Strategy, Planning, and Research
  • Land Forces and Warfare
  • Military Administration
  • Military Life and Institutions
  • Naval Forces and Warfare
  • Other Warfare and Defence Issues
  • Peace Studies and Conflict Resolution
  • Weapons and Equipment

Thinking and Reasoning: A Very Short Introduction

  • < Previous chapter
  • Next chapter >

6 (page 82) p. 82 Are we rational?

  • Published: September 2017
  • Cite Icon Cite
  • Permissions Icon Permissions

Human thinking and reasoning can be compared with a ‘normative’ standard—a formal theory of right and wrong answers. The normative theories mostly applied are decision theory, probability theory, and logic. People frequently make errors by these standards and have been shown to have many cognitive biases. Does this mean that human beings must be intrinsically irrational? ‘Are we rational?’ considers different definitions of rationality: instrumental, epistemic, bounded, normative, ecological, and evolutionary rationality. It also asks how important is general intelligence in rationality? More recent psychological research suggests that both instrumental and epistemic rationality, defined by conventional means, are aided by a combination of general intelligence and rational thinking disposition.

Signed in as

Institutional accounts.

  • GoogleCrawler [DO NOT DELETE]
  • Google Scholar Indexing

Personal account

  • Sign in with email/username & password
  • Get email alerts
  • Save searches
  • Purchase content
  • Activate your purchase/trial code

Institutional access

  • Sign in with a library card Sign in with username/password Recommend to your librarian
  • Institutional account management
  • Get help with access

Access to content on Oxford Academic is often provided through institutional subscriptions and purchases. If you are a member of an institution with an active account, you may be able to access content in one of the following ways:

IP based access

Typically, access is provided across an institutional network to a range of IP addresses. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.

Sign in through your institution

Choose this option to get remote access when outside your institution. Shibboleth/Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic.

  • Click Sign in through your institution.
  • Select your institution from the list provided, which will take you to your institution's website to sign in.
  • When on the institution site, please use the credentials provided by your institution. Do not use an Oxford Academic personal account.
  • Following successful sign in, you will be returned to Oxford Academic.

If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.

Sign in with a library card

Enter your library card number to sign in. If you cannot sign in, please contact your librarian.

Society Members

Society member access to a journal is achieved in one of the following ways:

Sign in through society site

Many societies offer single sign-on between the society website and Oxford Academic. If you see ‘Sign in through society site’ in the sign in pane within a journal:

  • Click Sign in through society site.
  • When on the society site, please use the credentials provided by that society. Do not use an Oxford Academic personal account.

If you do not have a society account or have forgotten your username or password, please contact your society.

Sign in using a personal account

Some societies use Oxford Academic personal accounts to provide access to their members. See below.

A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions.

Some societies use Oxford Academic personal accounts to provide access to their members.

Viewing your signed in accounts

Click the account icon in the top right to:

  • View your signed in personal account and access account management features.
  • View the institutional accounts that are providing access.

Signed in but can't access content

Oxford Academic is home to a wide variety of products. The institutional subscription may not cover the content that you are trying to access. If you believe you should have access to that content, please contact your librarian.

For librarians and administrators, your personal account also provides access to institutional account management. Here you will find options to view and activate subscriptions, manage institutional settings and access options, access usage statistics, and more.

Our books are available by subscription or purchase to libraries and institutions.

  • About Oxford Academic
  • Publish journals with us
  • University press partners
  • What we publish
  • New features  
  • Open access
  • Rights and permissions
  • Accessibility
  • Advertising
  • Media enquiries
  • Oxford University Press
  • Oxford Languages
  • University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

  • Copyright © 2024 Oxford University Press
  • Cookie settings
  • Cookie policy
  • Privacy policy
  • Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.


  1. Rational Thinking In Psychology

    essay on rational thinking

  2. Easy Steps On Writing Critical Thinking Essays

    essay on rational thinking

  3. What is Rational Thinking

    essay on rational thinking

  4. Logic & Analytical Thinking: Solve Complex Problems, Become Smarter and

    essay on rational thinking

  5. The Assessment of Rational Thinking: IQ ≠ RQ

    essay on rational thinking

  6. Ayn Rand Quote: “A rational man is guided by his thinking

    essay on rational thinking


  1. Rational Thinking Cell

  2. What is Rational Thinking?

  3. #Rational Thinking #lord buddha#journey

  4. Rational Thinking about Hope

  5. askcliffe on rational thinking and love

  6. Belonging Again...and Heidegger


  1. Why Is It So Hard to Be Rational? | The New Yorker

    By this definition, to be a rational person you have to know things, you have to want things, and you have to use what you know to get what you want. Intentions matter: a person isn’t rational ...

  2. The myth of rational thinking - Vox

    The myth of rational thinking. Why our pursuit of rationality leads to explosions of irrationality. By Sean Illing @seanilling [email protected] Apr 25, 2019, 8:10am EDT. Humans are hardly ...

  3. What is the value of rationality, and why does it matter?

    In the past, most philosophers assumed that the central notion of rationality is a normative or evaluative concept: to think rationally is to think properly or well—in other words, to think as one should think. Rational thinking is in a sense good thinking, while irrational thinking is bad. Recently, however, philosophers have raised several objections to that assumption.

  4. Critical Thinking - Stanford Encyclopedia of Philosophy

    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 for thinking ...

  5. Rationalism vs. Empiricism - Stanford Encyclopedia of Philosophy

    The dispute between rationalism and empiricism takes place primarily within epistemology, the branch of philosophy devoted to studying the nature, sources, and limits of knowledge. Knowledge itself can be of many different things and is usually divided among three main categories: knowledge of the external world, knowledge of the internal world ...

  6. How to encourage and train rational thinking in students

    4. Talk about thinking with your students. For students to develop their rational faculties, they need to be aware of their own thinking. By being more aware, students can train themselves to recognize — and avoid — careless thinking. Reflective practices like learning journals prompt students to visualize how their understanding has ...

  7. Rationalism | Definition, Types, History, Examples, & Descartes

    rationalism, in Western philosophy, the view that regards reason as the chief source and test of knowledge. Holding that reality itself has an inherently logical structure, the rationalist asserts that a class of truths exists that the intellect can grasp directly. There are, according to the rationalists, certain rational principles ...

  8. In Praise of ‘Rationality’ - The New York Times

    Maybe it is wise to learn to walk before you learn to run. Anthony Gottlieb’s most recent book is “The Dream of Enlightenment: The Rise of Modern Philosophy.”. RATIONALITY. What It Is, Why ...

  9. Rational Thinking | SpringerLink

    Rational thinking (or more formally, information processing) refers to differences across individuals in their tendency and need to process information in an effortful, analytical manner using a rule-based system of logic (Epstein et al. 1996; Scott and Bruce 1995; Stanovich and West 1998; Phillips et al. 2016 ).

  10. Are we rational? | Thinking and Reasoning: A Very Short ...

    Human thinking and reasoning can be compared with a ‘normative’ standard—a formal theory of right and wrong answers. The normative theories mostly applied are decision theory, probability theory, and logic. People frequently make errors by these standards and have been shown to have many cognitive biases.