Man is not a Rational Animal

The ancient Greek philosopher Aristotle defined man as a rational animal. It is truly amazing how much ado has been made of this single declaration by so many people in subsequent ages. When Aristotle made this definition, he was imitating his teacher Plato, who in turn imitated his great hero Socrates, who spent much of his later years searching for definitions for certain words such as truth, beauty, goodness, and justice, while he sought to show that his fellow Athenians didn’t know anything, including those who were generally esteemed by the populace or had a reputation for knowledge or wisdom. Throughout the ages, because of their great admiration for this triumvirate of philosophizing fools, many readers of these self-proclaimed reasoning animals have likewise imitated them by repeating the things they said or wrote and by applying their method of reasoning to as many different areas of study as possible. But it cannot be said that this is evidence of these people’s rationality or intelligence, since Aristotle’s definition that men, and more generally human beings, are rational animals is wrong.

First of all, why is a definition of man or humanity necessary? Is there any human being in the world who is so perceptually challenged or confused that one is not able to tell a human being apart from a non-human animal, organism, or object, and thus needs a precise definition in order to do so? Second, and more importantly, when people are not reasoning, reason is a very poor guide to understanding their behaviour. In this regard, reasoning is no different from all the many other acquired human skills that some human animals value, practise, and take the necessary time to acquire. Some examples are playing a board game like chess or playing a musical instrument like the guitar, which, just like reasoning, are other uniquely human activities. And just as knowing that a person plays chess or the guitar, or the manner in which one does so, is of little or no use in helping us to understand the person’s behaviour when one is not playing chess or the guitar, neither is reason of much use in helping us to understand a person’s behaviour when one is not engaged in this activity.

Reasoning is only one of the many different things that people do. And it is not even the only thing we humans do that differentiates us from other animals. For example, human beings are the only animals that laugh,[1] make and wear clothes, eat in restaurants where other members of our species cook, prepare, and serve us food, compose and listen to music that is produced with human-made instruments, write books and read them, torture other members of our species, make and watch movies, build prisons in which some humans are held for varying lengths of time, burn the dead bodies of our loved ones on a pyre or bury them in the ground and erect an engraved stone as a marker, drive in cars and fly in airplanes, pick flowers and give them to someone we like, speak through a telephone with a person who is not near enough so that we can communicate directly with the person, try people in law courts for committing certain actions that are deemed socially unacceptable and punish offenders, send our children to school for many years, manufacture substitutes for mother’s milk which are made with the milk produced by another mammal, live in dwellings that are artificially heated in winter and artificially cooled in summer, excavate ancient forms of converted solar energy and burn them in order to make or do various things, invent and play games and sports such as card games, football, rugby, ping pong, mah jong, and basketball, study the behaviour of other organisms and communicate this information to our fellow creatures, for no other purpose than to increase our knowledge about them, and use fire to cook our food and warm ourselves.

This list of uniquely human activities that are not performed by the members of any other species could be greatly expanded. Of course, many of these activities were not performed by anyone in the much simpler cultural and technological world in which Aristotle lived, and thus were not available for his consideration. But even so, why should the single activity of reasoning be given precedence – over all of these other uniquely human activities – as the defining characteristic that differentiates our species from all other species? Why, for example, could our species not be defined as the laughing animal, or the clothes-making and wearing animal, or the movie-watching, chess-playing, prison-building, criminal-trying and punishing, artificial-milk producing, fire-kindling, air-conditioning-using, gun-manufacturing, science-studying, car-driving, telephone-using, or television-watching animal? There are various ways to answer this question, but one answer is that many of us non-rational animals have been too busy imitating Aristotle and his countless other imitators by continuing to believe and declare, as if it were a self-evident truth which has been established merely by the very large number of people who believe and continue to repeat it, that “human beings are rational animals.”

What these examples illustrate is that reasoning is only one of the myriad activities that people perform during their lives. Moreover, it is an activity that only some of us perform some of the time. For the truth is that the great majority of human beings spend very little time engaged in deliberate reasoning – in performing the one, single activity that, according to Aristotle, defines our entire species and differentiates us from all other animals.

Another important point is that, like almost all of these other uniquely human activities, reasoning is a behaviour that must be learned. And the way it is learned is by observing and learning from others who know how to perform the activity correctly. Until recently, the vast majority of human beings had never observed this activity being performed by a member of the community in which they lived. Not surprisingly, these people not only spent no time in deliberate logical reasoning, they did not know how to reason. This is no different from the fact that someone who has never observed others speaking a certain language, playing a certain game, sport, or musical instrument, using a computer, flying a plane, and so on, will not know how to perform that activity.

A characteristic that is claimed to define an entire species must be possessed by every single member of that species, which is clearly not true of our much-vaunted ability to reason. That this obvious falsehood has been so widely repeated is evidence, not of our rationality, but of our imitative nature, since those who spend the greatest amount of time in deliberate reasoning are those who greatly admire famous reasoning animals like Socrates, Plato, and Aristotle, along with their legion of philosophical and intellectual imitators.

Aristotle’s widely-repeated definition would have been more useful if the activity of reasoning had proved to be a sure guide to discovering or arriving at the truth. But reason has shown itself to be a wayward guide that has beguiled, deceived, and misled many a devoted reasoner into a very large number of false paths and dead ends. Innumerable are the mistakes that have been made by the admirers of these ancient Greek philosophers, including even the most celebrated among them. Furthermore, it is usually not possible, solely by the criterion of reason, to determine which of two or more alternative statements is true. To do this, we must have recourse to the real world, and not remain confined, like a puppy that delights in chasing its own tail, in the imaginary and artificial logical world that is sometimes created by our too-fertile brains. Even in Aristotle’s many writings, we find numerous examples of, not necessarily faulty reasoning, but of incorrect conclusions that are logically derived from mistaken premises or incomplete information about the world. This single fact – that Aristotle’s many admirers have failed to deduce from this disparity between his widely-imitated method and the results obtained by it that reason is not always the best guide to discovering the truth – clearly shows that we human beings most certainly are not rational creatures.

The common assumption that someone who knows how to reason is less likely to make mistakes about the world in general, and about human relationships in particular, is not always justified. For who among us, when we are troubled or unsure about which course of action we should take, would seek the advice of a philosopher?

Reasoning is merely an activity that is performed by some people some of the time. What is more, in the past, the great majority of people did not know how to reason because this is a learned skill, just as knowing how to speak or write a particular language, play the saxophone, grow vegetables, solve mathematical equations, fix a car, and build a house are also learned skills. And to say otherwise, by insisting that we are indeed rational creatures, is merely to continue imitating the egregious mistake made by Aristotle and his many foolish imitating admirers.


[1] Although some people have claimed there are some non-human animals that exhibit a behaviour which they would call laughter, it does not serve the same function that laughter does in our case, which is to make us feel embarrassed at a failure to imitate those that we see around us and change our behaviour so that it conforms to their behaviour. As in other cases, we should be wary of anthropomorphizing other animals, a common tendency that is due, in large part, to the prevalence of fables and stories in which human characteristics and behaviours are carelessly and mistakenly attributed to them.