Plato and Aristotle: How Do They Differ?

Plato (left) and Aristotle, detail from School of Athens, fresco by Raphael, 1508-11; in the Stanza della Segnatura, the Vatican. Plato points to the heavens and the realm of Forms, Aristotle to the earth and the realm of things.

Plato (c. 428–c. 348 BCE) and Aristotle (384–322 BCE) are generally regarded as the two greatest figures of Western philosophy. For some 20 years Aristotle was Plato’s student and colleague at the Academy in Athens, an institution for philosophical, scientific, and mathematical research and teaching founded by Plato in the 380s. Although Aristotle revered his teacher, his philosophy eventually departed from Plato’s in important respects. Aristotle also investigated areas of philosophy and fields of science that Plato did not seriously consider. According to a conventional view, Plato’s philosophy is abstract and utopian, whereas Aristotle’s is empirical, practical, and commonsensical. Such contrasts are famously suggested in the fresco School of Athens (1510–11) by the Italian Renaissance painter Raphael, which depicts Plato and Aristotle together in conversation, surrounded by philosophers, scientists, and artists of earlier and later ages. Plato, holding a copy of his dialogue Timeo (Timaeus), points upward to the heavens; Aristotle, holding his Etica (Ethics), points outward to the world.

Although this view is generally accurate, it is not very illuminating, and it obscures what Plato and Aristotle have in common and the continuities between them, suggesting wrongly that their philosophies are polar opposites.

So how exactly does Plato’s philosophy differ from Aristotle’s? Here are three main differences.

Forms. The most fundamental difference between Plato and Aristotle concerns their theories of forms. (When used to refer to forms as Plato conceived them, the term “Form” is conventionally capitalized, as are the names of individual Platonic Forms. The term is lowercased when used to refer to forms as Aristotle conceived them.) For Plato, the Forms are perfect exemplars, or ideal types, of the properties and kinds that are found in the world. Corresponding to every such property or kind is a Form that is its perfect exemplar or ideal type. Thus the properties “beautiful” and “black” correspond to the Forms the Beautiful and the Black; the kinds “horse” and “triangle” correspond to the Forms the Horse and the Triangle; and so on.

A thing has the properties it has, or belongs to the kind it belongs to, because it “participates” in the Forms that correspond to those properties or kinds. A thing is a beautiful black horse because it participates in the Beautiful, the Black, and the Horse; a thing is a large red triangle because it participates in the Large, the Red, and the Triangle; a person is courageous and generous because he or she participates in the Forms of Courage and Generosity; and so on.

For Plato, Forms are abstract objects, existing completely outside space and time. Thus they are knowable only through the mind, not through sense experience. Moreover, because they are changeless, the Forms possess a higher degree of reality than do things in the world, which are changeable and always coming into or going out of existence. The task of philosophy, for Plato, is to discover through reason (“dialectic”) the nature of the Forms, the only true reality, and their interrelations, culminating in an understanding of the most fundamental Form, the Good or the One.

Aristotle rejected Plato’s theory of Forms but not the notion of form itself. For Aristotle, forms do not exist independently of things—every form is the form of some thing. A “substantial” form is a kind that is attributed to a thing, without which that thing would be of a different kind or would cease to exist altogether. “Black Beauty is a horse” attributes a substantial form, horse, to a certain thing, the animal Black Beauty, and without that form Black Beauty would not exist. Unlike substantial forms, “accidental” forms may be lost or gained by a thing without changing its essential nature. “Black Beauty is black” attributes an accidental form, blackness, to a certain animal, who could change color (someone might paint him) without ceasing to be himself.

Substantial and accidental forms are not created, but neither are they eternal. They are introduced into a thing when it is made, or they may be acquired later, as in the case of some accidental forms.

Ethics. For both Plato and Aristotle, as for most ancient ethicists, the central problem of ethics was the achievement of happiness. By “happiness” (the usual English translation of the Greek term eudaimonia), they did not mean a pleasant state of mind but rather a good human life, or a life of human flourishing. The means by which happiness was acquired was through virtue. Thus ancient ethicists typically addressed themselves to three related questions: (1) What does a good or flourishing human life consist of?, (2) What virtues are necessary to achieve it?, and (3) How does one acquire those virtues?

Plato’s early dialogues encompass explorations of the nature of various conventional virtues, such as courage, piety, and temperance, as well as more general questions, such as whether virtue can be taught. Socrates (Plato’s teacher) is portrayed in conversation with presumed experts and the occasional celebrity; invariably, Socrates exposes their definitions as inadequate. Although Socrates does not offer his own definitions, claiming to be ignorant, he suggests that virtue is a kind of knowledge, and that virtuous action (or the desire to act virtuously) follows necessarily from having such knowledge—a view held by the historical Socrates, according to Aristotle.

In Plato’s later dialogue Republic, which is understood to convey his own views, the character Socrates develops a theory of “justice” as a condition of the soul. As described in that work, the just or completely virtuous person is the one whose soul is in harmony, because each of its three parts—Reason, Spirit, and Appetite—desires what is good and proper for it and acts within proper limits. In particular, Reason understands and desires the good of the individual (the human good) and the Good in general. Such understanding of the Form of the Good, however, can be acquired only through years of training in dialectic and other disciplines, an educational program that the Republic also describes. Ultimately, only philosophers can be completely virtuous.

Characteristically, for Aristotle, happiness is not merely a condition of the soul but a kind of right activity. The good human life, he held, must consist primarily of whatever activity is characteristically human, and that is reasoning. The good life is therefore the rational activity of the soul, as guided by the virtues. Aristotle recognized both intellectual virtues, chiefly wisdom and understanding, and practical or moral virtues, including courage and  temperance. The latter kinds of virtue typically can be conceived as a mean between two extremes (a temperate person avoids eating or drinking too much but also eating or drinking too little). In his Nicomachean Ethics, Aristotle held that happiness is the practice of philosophical contemplation in a person who has cultivated all of the intellectual and moral virtues over much of a lifetime. In the Eudemian Ethics, happiness is the exercise of the moral virtues specifically in the political realm, though again the other intellectual and moral virtues are presupposed.

Politics. The account of justice presented in Plato’s Republic is not only a theory of virtue but also a theory of politics. Indeed, the character Socrates there develops a theory of political justice as a means of advancing the ethical discussion, drawing an analogy between the three parts of the soul—Reason, Spirit, and Appetite—and the three classes of an ideal state (i.e., city-state)—Rulers, Soldiers, and Producers (e.g., artisans and farmers). In the just state as in the just individual, the three parts perform the functions proper to them and in harmony with the other parts. In particular, the Rulers understand not only the good of the state but, necessarily, the Good itself, the result of years of rigorous training to prepare them for their leadership role. Plato envisioned that the Rulers would live simply and communally, having no private property and even sharing sexual partners (notably, the rulers would include women). All children born from the Rulers and the other classes would be tested, those showing the most ability and virtue being admitted to training for rulership.

The political theory of Plato’s Republic is notorious for its assertion that only philosophers should rule and for its hostility toward democracy, or rule by the many. In the latter respect it broadly reflects the views of the historical Socrates, whose criticisms of the democracy of Athens may have played a role in his trial and execution for impiety and other crimes in 399. In one of his last works, the Laws, Plato outlined in great detail a mixed constitution incorporating elements of both monarchy and democracy. Scholars are divided over the question of whether the Laws indicates that Plato changed his mind about the value of democracy or was simply making practical concessions in light of the limitations of human nature. According to the latter view, the state of the Republic remained Plato’s ideal, or utopia, while that of the Laws represented the best that could be achieved in realistic circumstances, according to him.

In political theory, Aristotle is famous for observing that “man is a political animal,” meaning that human beings naturally form political communities. Indeed, it is impossible for human beings to thrive outside a community, and the basic purpose of communities is to promote human flourishing. Aristotle is also known for having devised a classification of forms of government and for introducing an unusual definition of democracy that was never widely accepted.

According to Aristotle, states may be classified according to the number of their rulers and the interests in which they govern. Rule by one person in the interest of all is monarchy; rule by one person in his own interest is tyranny. Rule by a minority in the interest of all is aristocracy; rule by a minority in the interest of itself is oligarchy. Rule by a majority in the interest of all is “polity”; rule by a majority in its own interest—i.e., mob rule—is “democracy.” In theory, the best form of government is monarchy, and the next best is aristocracy. However, because monarchy and aristocracy frequently devolve into tyranny and oligarchy, respectively, in practice the best form is polity.

WRITTEN BY:  Brian Duignan 

What Is It Like to Be a Bee?


A single pound of honey is the lifetime work for about 768 bees, made up of visits to two million flowers.

A single pound of honey is the lifetime work for about 768 bees, made up of visits to two million flowers. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

You’re a honeybee. Despite being around 700,000 times smaller than the average human, you’ve got more of almost everything. Instead of four articulated limbs, you have six, each with six segments. (Your bee’s knees, sadly, don’t exist.) You’re exceptionally hairy. A shock of bristly setae covers your body and face to help you keep warm, collect pollen, and even detect movement. Your straw-like tongue stretches far beyond the end of your jaw, but has no taste buds on it. Instead, you “taste” with other, specialized hairs, called sensillae, that you use to sense the chemicals that brush against particular parts of your body.

You’ve got five eyes. Two of them, called compound eyes and made up of 6,900 tiny lenses, take up about half your face. Each lens sends you a different “pixel,” which you use to see the world around you. The colors you see are different. Red looks like black to you and your three “primary” colors are blue, green, and ultraviolet. You detect motion insanely well, but outlines are fuzzy and images blocky, like a stained-glass window. (Your three other eyes detect only changes in light to tell you quickly if something dangerous is swooping your way.)

Now that you’re a honeybee you can do all kinds of things you couldn’t before. Your four wings move at 11,400 strokes per minute. You can sense chemicals in the air. You’re fluent in waggle dance, so you’re able to tell the other members of your colony where the nectar supplies are. But how much does any of this tell us about what it actually feels like to be a bee?

Around 80 percent of all American fruit, vegetable, and seed crops are pollinated by bees.
Around 80 percent of all American fruit, vegetable, and seed crops are pollinated by bees. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

We all know what it’s like to be ourselves—to be conscious of the world around us, and be conscious of that consciousness. But what consciousness means more generally, for other people and other creatures, is a hot potato tossed between philosophers, biologists, psychologists, and anyone who’s ever wondered whether it feels the same to be a dog as it does to be an octopus. In general, we think that if you have some kind of unique, subjective experience of the world, you’re conscious to some extent. The problem is that in trying to envisage any consciousness besides our own, we run into the limits of the human imagination. In the case of honeybees, it’s hard to know if interesting behavior is reflective of an interesting experience of the world or masks a more simple stimulus-response existence. The lights are on, but is anyone home? To examine these questions means to take a ride on that hot potato—from philosopher to scientist and back again and again and again.

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More and more, scientific research seems to suggest that bees do have a kind of consciousness, even as myths and misconceptions about their capacities persist. In a recent TED Talkcognitive scientist Andrew B. Barron of Macquarie University in Sydney, Australia, described how he had had to be lovingly “talked down” from a “pearl-clutching” moment after someone asked him whether bees actually have brains. They do, of course.

Understanding what their consciousness might look or feel like is probably a fool’s errand. It’s really hard to imagine what it’s like to be almost anything or anyone other than what you are, says philosopher Colin Klein, also from Macquarie University, who has worked extensively alongside Barron. With people, it’s much easier. “You can talk to them, you can read fiction, there are a lot of things you can do—but it takes a certain amount of work to get into that space and in particular to realize what you experience, what you don’t experience, what your horizons look like,” he says. But the more different the experience of the organism you’re trying to imagine is, the harder it becomes. “You can start to think at least in what senses the experience of something like a bee might be different from ours”—how they structure the world around them, say, or whether they experience “space” the way we do.

The philosopher Thomas Nagel’s famous 1974 essay, “What Is It Like to Be a Bat?” suggests that being “like” something else is possible only if the target is conscious of the world around it. “The fact that an organism has conscious experience at all means, basically, that there is something it is like to be that organism,” he writes. Or, “fundamentally an organism has conscious mental states if and only if there is something that it is to be that organism—something it is like for the organism.” On top of that mindscrabble, our ability to imagine ourselves as another being is limited by the world that we know—as people. We might be able to imagine having webbed arms and hands, like a bat, or five eyes, like a bee, but the specific senses and abilities these animals possess are frankly inconceivable. “I want to know what it is like for a bat to be a bat. Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task,” he adds. Moreover, “I cannot perform it either by imagining additions to my present experience, or by imagining segments gradually subtracted from it.”

Despite these difficulties, what we want to know, Klein and Barron wrote in an op-edin The Conversation in 2016, is whether bees and other insects “can feel and sense the environment from a first-person perspective.”

Each hive is made up of a single queen and many workers and drones.
Each hive is made up of a single queen and many workers and drones. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

It seems likely that there are lots of different kinds of consciousness, of varying levels of complexity. As human beings, not only are we aware of ourselves and the world around us, we’re also aware of that awareness. A step down in complexity might lack that awareness of self-awareness. And a step down from that might be limited to a distinctive experience of the external world only.

Such a simple ladder may not be the best way to organize this kind of complexity, says David Chalmers, a leather jacket-wearing Australian philosopher at New York University best known for his work in philosophy of mind—a branch of philosophy that asks these kinds of questions. “But there are probably different ways of arranging states of mind, or consciousness, in a hierarchy,” he says. What’s harder to distinguish is the precise point where consciousness ends, and what the light switch, “on-off,” moment might be, further down the evolutionary chain. “It’s awfully hard to see what a borderline case of being conscious would be,” he says, even while it’s not that hard to know what a borderline case of being alive might look like, as in a virus. “It would sort of feel like something,” he says, trailing off in thought, “but not.”

So far as bee consciousness goes, however, he thinks there are likely to be some factors in consciousness that we share, like vision, and some that we don’t at all, “whether it’s sensory systems that humans have that bees don’t have, or whether it’s things more like concepts, like language, that give us a kind of consciousness that bees don’t have.”

Klein is more specific. “We think that bees have experiences that feel like something to the bee,” he says. “We don’t think the bees are aware of having experiences that feel like something to them. The bee is not going round saying to itself, ‘Gee, it’s a lovely day, look at that flower.’ It doesn’t have any of these more sophisticated, reflexive kinds of consciousness.”

Of 20,000 species of bees, only four make honey.
Of 20,000 species of bees, only four make honey. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

Still, despite having a brain that is a fraction of the size of even the tiniest mammal’s, bees seem capable of some incredibly complex behaviors and mental gymnastics. Studies over the last few decades have revealed them to do everything from having a concept of zero to experiencing emotion, from tool use to social learning. If you give them cocaine, they dance more vigorously and tend to overestimate how much pollen they’ve foraged. If they watch a plastic bee scoring goals with a soccer ball, they can follow suit for a sugar water reward. Wouldn’t these complex behaviors be enough to assume some kind of consciousness? Not necessarily, says Barron. “Honeybees are unusual among the insects in that they have a whole list of clever things that they are able to do,” he says. “And some people would say that that means that they are more likely to be conscious. I disagree with that.”

Think of all the other things able to perform complicated tasks that we’re pretty sure aren’t conscious. Robots do everything from juggle to play the piano, but, as far as we know, are “dark” inside. Like bees, Roomba vacuum cleaners make decisions, navigate around the world, and adapt—but there’s probably nothing it’s “like” to be one of them. And plants have been shown to have a kind of memory: Over time, for example, they can learn that being repeatedly dropped isn’t anything to freak out about. But few suggest they possess consciousness.

“I think this is one of the problems with the behavioral approach, is that it encourages this looking for very clever things,” says Klein. “Whereas if consciousness is a widespread phenomenon, you should expect that it might be in a lot of different types of things that don’t necessarily do the things that we take to be markers of consciousness.”

If behavior can’t enough tell us about the inner life of a bee, perhaps the structure of their sesame seed–sized brains can. In a human brain, key studies suggest consciousness lies in the midbrain, an evolutionarily much older section. In a study published last year, Barron and Klein investigated the structure of the bee brain, which seems to be made up of similar bits to our own, with a region responsible for similar tasks. “It’s smaller, it’s organized differently, it’s different-shaped, but if you look at the kind of computations it does, it’s doing the same sort of things as the midbrain,” Klein says. “So if you think in humans the midbrain is responsible for being conscious, and you think this is doing the same kind of thing, then you ought to think insects are conscious as well.”

Regardless of outside temperature, bees maintain a temperature of 92–93 degrees Fahrenheit in their central brood nests.
Regardless of outside temperature, bees maintain a temperature of 92–93 degrees Fahrenheit in their central brood nests. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

This biological approach opens up consciousness to a variety of other organisms that don’t do the clever things that bees do, like beetles or potato bugs. They might be less obviously interesting, but that doesn’t make them less likely to be conscious. The technology that allows us to examine insect brains on a neuron-by-neuron level is very new, Barron says. “If they really are instinctive, then we’re learning something about what the insect brain is capable of. If they’re not, then we’re learning something more profound.”

The technology also allows us to map the brains of organisms that we think probably aren’t conscious, and assess what they lack. Caenorhabditis elegans is a roundworm commonly used in scientific research. In recent years, scientists have developed a connectome—a sort of complex brain map—for this tiny soil-dweller, which measures barely a millimeter in length. “They have 302 neurons,” says Klein, compared to a bee’s 960,000 and a human’s 86 billion. “Those [worms], we think, are actually very much like robots, like complicated robots.” If exposed to a particular stimulus, they respond in a particular, predictable way. “Unless there’s some kind of danger, and then it does that, unless it’s hungry, and then it does this—so you can really map out what it’s going to do.” In bees, he says, there seems to be a kind of qualitative shift, in which the brain is somehow more than its connections.

Honeybees fly at speeds of up to 15 miles an hour.
Honeybees fly at speeds of up to 15 miles an hour. USGS BEE INVENTORY AND MONITORING LAB/PUBLIC DOMAIN

All of this neurobiology is beginning to paint a picture—that it feels like nothing to be a C. elegans, or a robot, or a plant, but it probably feels like something to be a bee. If that’s the case, it is still not known where, between the roundworm and the honeybee, that awareness switches on, if it does. While neurobiology is a very important part of the story, says Chalmers, “it may not settle the issue of consciousness. You very frequently find a situation where two people might agree on the neurobiology of a given case, but disagree on what that implies about consciousness.” He gives the example of fish, and the ongoing discourse about whether their neurobiology suggests that they do or do not feel pain. “Knowing the neurobiological facts doesn’t necessarily settle the question.”

We can try to imagine what it’s like to have six hairy legs, or see in pixels, or crave nectar. We can even try to imagine what it’s like to be part of a hive, a superorganism with motivations of its own. But what it’s actually like to be a bee—its subjective experience of the world—is going to remain elusive. But we’re starting to figure out that it’s probably like something. And that’s not nothing.