Why Plato thought that the whole world was alive and had a soul

Plato (428 - 348 BC), in a few of his writings, explains that the whole world has a soul and is a living thing. Let’s talk about why.

First, we should say what the ancient Greeks thought a soul was.

They defined the word ‘soul’ to mean the source of life. We can think of the soul as whatever makes someone be alive. This might be striking because today, the word ‘soul’ is closely associated with religious traditions and can even mean something like ‘the mysterious, ineffable, and inner part of a person’. The Greeks, in contrast, thought that the definition of ‘soul’ was something uncontroversial and simple. Souls are whatever explains the existence of life in some body.

However, the association of the soul with religious traditions comes later and takes advantage of the Greek philosophical idea of the soul.

Ancient philosophical debates were not about how to define the term ‘soul’ and instead usually took for granted the definition that I’ve just presented. Ancient philosophers were far more interested in the following two questions.

1) Is the soul immortal?

2) Is the soul made of material, physical things, or is it something immaterial?

You might be surprised to hear that ancient Greek philosophers thought that the soul could exist and be mortal, and they also thought that the soul could exist and be a physical, material thing. The answer is even more surprising: most ancient Greek philosophical traditions affirmed that the soul existed and yet was mortal and material.

This flies in the face of our understanding of the soul today. If someone says that they believe in the soul today, they almost certainly mean that they believe in some immaterial, immortal part of a human being. However, that isn’t what Greeks mean. Some philosophers did think that the soul existed as an immortal, immaterial thing, but that wasn’t guaranteed once you believed in the soul.

The second surprising thing is that virtually every Greek philosopher believed that the soul existed! That’s because of the definition of the ‘soul’ as the source of life. This definition can sound sort of tendentious because it makes anyone who doesn’t believe in the soul sound like they’re denying something obvious: namely, that life exists. That strikes some people as a bit unfair: it’s like the Greeks are defining the term ‘soul’ in such a way as to render it obvious.

However, this makes more sense if you bear in mind that you don’t have to believe that the soul is immortal and immaterial once you’ve agreed that souls exist because life does. The controversial parts are whether the soul is immortal and immaterial, not whether it exists at all.

So, let me give an example. Epicureanism was a major school of Greek philosophical thought that was founded in the Hellenistic period (323 - 31 BC). The Epicureans believed that the soul existed, but that it was both mortal and material. Why? The reason is that they believed what made a body alive was atoms. Atoms are material things that cause someone to be alive, so the soul is atoms, and atoms scatter when we die, so the soul doesn’t survive our death.

If you wanted to argue that the soul was immaterial and immortal, you could, but you had to argue that the source of life was not material and could somehow survive our deaths.

So, before we ask why Plato thought that the whole world had a soul, we should ask one more quick question: did every single Greek philosopher really believe in the soul? And the answer is ‘no’, but this denial is very rare.

There is a little-known philosopher named Dicearchus who seems to have denied the existence of the soul. We don’t know exactly when he lived, but he was reportedly a student of Aristotle (384 - 322 BC), and so he lived at some point in the 300s BC. None of his works remain, but Cicero (106 - 43 BC) tells the following story:

“Dicearchus brought on a certain Pherecrates, an old man of Phthia, said to be a descendant of Deucalion, who explained that the soul is nothing at all; it is a completely empty name, and to speak of animate or ‘be-souled’ beings is meaningless: there is neither rational nor irrational soul in man or beast and all that power by which we act or apprehend is spread evenly through all living bodies and inseparable from the body; for it is nothing in itself and there is nothing except one simple body, so fashioned that it lives and apprehends owing to its natural composition” (Tusculan Disputations 1.21).

Cicero is saying that Dicearchus (and Pherecrates) denied the existence of the soul because they thought that since you could explain the existence of life totally and completely by means of bodily things, you didn’t really have to affirm the existence of the soul. In this sense, ‘soul’ becomes an empty name, that is to say, a name for nothing at all.

Most philosophers in antiquity disagreed. They thought that once you discovered the source of life, you discovered the soul, and the name ‘soul’ couldn’t be empty so long as there was a source of life — because the word ‘soul’ names whatever that source is.

Plato’s own position on this question was that the soul was immortal and immaterial. The Platonic school of philosophy was, in fact, the only major school to take this position. We can explore why Plato thought this in another post, but we are especially well-positioned right now to explore why Plato thought that the whole world (by which I mean the universe or cosmos) had a soul. Let’s tackle this!

The answer is that it has a soul because it is alive.

If it is alive, then it has a soul because souls are the things that explain why something is alive.

Now we have to ask: why is it alive?

The universe contains living things, but that doesn’t mean that it itself is alive, and Plato doesn’t try to draw any conclusions from the fact that the world contains living things.

Instead, Plato thinks that the core of life is self-motion. What distinguishes living things from inanimate objects is the ability to move oneself. Rocks, for instance, are inanimate because they are unable to be sources of motion for themselves. Rocks wait until they get picked up or blown around. Plants and animals, in contrast, can move themselves. Plants put down roots and can tilt themselves towards the sun. Animals can swim, walk, fly, and so on. Even some of the simplest organisms on Earth will engage in basic physiological processes, such as reproduction, respiration, and energy production, which constitute motions, even if they don’t involve something moving around in space.

Plato thinks that the universe is alive because it too moves itself. Today, we know that the universe is constantly expanding. For Plato, that would be evidence of the universe’s life (and, therefore, soul) because it is motion initiated by the universe itself. In Plato’s day, this fact was unknown, but he relied on other kinds of motions of the universe, such as the orbit of the universe around the Earth. It turns out that the universe doesn’t really revolve around the Earth, but Plato thought it did, so he concluded that the universe moved. His conclusion was right, and he would have inferred it from the expansion of the universe if he had known about it.

Note that this same reasoning means that many other things are alive, too. For instance, the planets orbit and so move themselves. Therefore, they are alive. Therefore, they have souls. Plato talks about this throughout the Timaeus: the planets are ensouled, living things.

This does not mean that the planets and universe are living things in the same way that we are. They are not necessarily persons with rich inner lives, and Plato is not saying that they have emotions or can somehow talk. If you’re wondering what they can do, the answer is that they can move themselves. That’s what it means to have a soul and be alive, according to Plato.

Can they think? Plato does think that the orderly, regular motion of the universe (and planets) is good evidence for the fact that they are beings endowed with reason. Irrational beings don’t move so regularly and in such an orderly fashion. Yet, he doesn’t really hold forth much on what their thoughts are about or what they are like. He seems to respect the fact that there’s not much we know or could know about what these beings are like. We can draw conclusions from only what we can observe about them: they move themselves in orderly fashions, from which we can infer that they are alive, ensouled, and rational.

The rationality that the world’s soul possesses is key for Plato. When God created the world, he wanted to make the world as good as possible, and rational things are better than non-rational ones. So, he needed to make the world rational, which meant that the world needed a soul in order to possess reason. This explains why God endowed the world with a soul. But as for why Plato thought that the world had a soul in the first place, we need to consider the sorts of inferences Plato was making and the sorts of observations of the world on which he based those inferences. Chiefly, those are astronomical observations about regular, orderly motion.