Socrates Plato Aristotle | World History | Khan Academy

Ancient Greece was not even a cohesive empire; it was made up of many city-states led by Athens and Sparta. But despite its fragmentation, it made innumerable contributions to not just Western civilization but civilization as a whole. Those are contributions in terms of forms of governance like democracy, contributions in medicine, contributions in the arts, in mathematics, and in the sciences. But perhaps their most famous contribution is in terms of philosophy.

If you're going to talk about philosophy in Ancient Greece, the most famous three philosophers are Socrates, Plato, and Aristotle. Now, before we get into the first of them, and really the teacher of Plato, who is then the teacher of Aristotle, let's get a little bit of context on this time period. As we enter into the 5th century BCE, a couple of things are emerging. First, you have a new Athenian democracy. Then, as you get into that century, the Persians invade, trying to conquer Greece several times, but unsuccessfully. But then the Greeks start fighting amongst themselves, led on one side by Athens and on the other side by Sparta. That's the Peloponnesian War, which ends with Sparta being victorious, but all of the Greek city-states being weakened dramatically.

Now, between the end—especially the first part of the Greco-Persian Wars—and the end of the Peloponnesian War, it was actually a time of Athenian prosperity. They were leading this semi-empire; they were investing in the arts, and it's often called the Golden Age of Athens. That's the world in which Socrates emerged. Like many philosophers, Socrates led a very interesting life, and it's worth noting that what we know about him does not come directly from his writing. We don't have surviving accounts of his writing; it comes mainly through the writing of his students, Xenophon and most notably Plato. We also get some parody of Socrates from Aristophanes, that Socrates himself did not appreciate much.

But what we know is that he started in life as a stonemason; he even acted as a soldier, a hoplite, during the Peloponnesian War. But he's, of course, most famous for being a philosopher and for being a teacher. His teaching style, the Socratic method, is still viewed as something of a best practice today—rather than lecturing students, to instead ask incisive questions that force a student to deepen their thinking and get closer to the root of an issue, and to learn how to think rather than just having knowledge transmitted to them.

Now, what's also notable about Socrates and his many students, including Plato and Aristotle, is that they took a departure from how to think about the world from most of the ancient world. Most of the ancient world was focused on the gods and the metaphysical, explaining everything. While the ancient Greeks did have a large pantheon of gods, Socrates and his fellow philosophers tried to figure out how the world works, why we are here, somewhat independent of the gods. They tried to reason it through; they tried to talk it through, think about it from a rational point of view. To get a flavor of that, here is a quote: "True wisdom comes to each of us when we realize how little we understand about life, ourselves, and the world around us."

So, unlike many ancient societies that just tried to explain everything through the metaphysical or through the gods, here you have Socrates saying, no, an ideal true wisdom is when you appreciate how little we know—this form of intellectual humility. Now, Socrates lived during this Golden Age of Athens, a time when democracy was flourishing, the Age of Pericles. But he himself was a little bit skeptical of unfettered or pure democracy. He was worried: well, what if the people voting aren't educated to make the types of decisions? Maybe they can be manipulated by a demagogue, someone who just tells them exactly what they want to hear.

So, he was a bit of a controversial figure, especially as you get to the end of the Peloponnesian War. Remember, Athens loses the Peloponnesian War; it went from being this powerful head of this Delian League, something of an empire, this wealthy city, and now it's a subjugated state. It's tired from war, and so you can imagine there's a lot of political infighting, and Socrates ends up being one of the casualties. He is actually put on trial by his fellow Athenians; this is a depiction of the trial of Socrates, and it shows Socrates defending himself from the accusations brought against him: refusing to recognize the gods acknowledged by the state, importing strange divinities of his own, corrupting the young.

In his defense, which both Xenophon and Plato write about, called an "Apology," he's bewildered. He says, where is all of this coming from? Now, it is true he did not invoke the gods when he was trying to explain the universe, and yes, he was trying to teach the young to think. But by no means, if you look at what he was doing—or at least our modern accounts coming through Plato and Xenophon—does it seem like he was trying to undermine the state in some way. But needless to say, it comes to a vote, and maybe he's a victim of his own fears of a pure democratic process. Amongst the 500 Athenians voting, 280 say that he is guilty, and 220 say that he is not guilty.

He's given a chance to think about what his penalty should be, and the charges, at least in the Athenians' minds, were quite serious. But Socrates famously says, "An unexamined life is not worth living." And so, even though many historians think that he might have been able to get exile if he asked for it, he was sentenced to death. This is a painting done much, much later of what that death of Socrates might have looked like. But you see here Socrates about to—or maybe he just drank the hemlock, which is the poison that will kill him.

So, even though he had to die for these pretty spurious allegations, his legacy lives on, and it lives on most famously in his student, Plato. Now, Plato is famous for many things. There's this notion of a Platonic ideal form, that whether you're talking about a circle, a ball, a dog, or a chair, that there's an ideal form that is independent of what your senses are telling you or what the chair in front of you might be—that that's an imperfect version of that ideal form. The word "platonic" in general, you'll hear applied to many different concepts, some of the meanings having changed over time.

The other thing that Plato is famous for is the notion of an academy. The place where he taught his students was a little field outside the walls of Athens, named for the Athenian hero Academos, and so that area became known as Plato's Academy. Ever since then, places of learning have often been referred to as academies, just like Khan Academy. But Plato was also concerned, like his teacher Socrates, with the nature of how we should be ruled. "There will be no end to the troubles of states, or indeed of humanity itself, till philosophers become rulers in this world, or till those we now call kings and rulers really and truly become philosophers." Political power and philosophy thus come into the same hands.

So, like Socrates, he's wary of how they have been governed, and remember, we're now after the period of the Peloponnesian War. The city-states of Greece, and especially Athens, have been dramatically weakened. So a lot of people might be thinking, including Plato, well, is there a better way to govern ourselves? Now, Plato's most famous student is Aristotle, and like his teacher, Aristotle is famous for many things and explored many dimensions of the universe. But he is probably most famous for being the tutor of Alexander the Great. When Alexander the Great was young, Philip of Macedon—Alexander the Great's father—as he conquers the weakened city-states after the Peloponnesian War, he also conquers Aristotle's hometown of Stageira, and he enslaves the population.

So when he goes to Aristotle to tutor his young son, who ends up being called Alexander the Great eventually, Aristotle says, okay, my fee will be the freedom of the people of my town. His town is freed; he tutors a young Alexander when Alexander's in his early teens. He also gets support for a center of learning; he creates a Lyceum, which is his version of Plato's Academy. Just like you saw with Socrates and you see with Plato, Aristotle continued this tradition of a focus on learning and a humble acceptance of all that there might be in the world.

This rationality that we now see in modern science, that you didn't see from a lot of the ancients who were focused on the metaphysics and the gods: "It is the mark of an educated mind to be able to entertain a thought without accepting it." I'll leave you there, but the big takeaway is going from Socrates to Plato to Aristotle. There were many other Greek philosophers, and you have the seed of what you could call modern rationality. Roughly 2,000 years later, you have the European Renaissance that starts re-emerging many of these same ideas, all the way providing a bridge into the Enlightenment and now our modern, hopefully fairly rational view of the world.