Why Plato thinks you should exercise

Exercise is the major way that we prevent disease, according to Plato's Timaeus

In the Timaeus, Plato (428 - 348 BC) argued that exercise was the most important and effective way to prevent the deterioration of our body due to disease. There are two major reasons for this, and they both reflect Plato’s criticisms of his contemporaries and predecessors who relied on more than just exercise, such as recommending drugs, to promote health.

There is absolutely no Greek thinker who relied exclusively on, say, drugs to promote health. Offerings to gods and lifestyle changes, such as exercise and fasting, featured prominently in ancient Greek medicine. Surgery was almost always out of the question for several reasons. There were dangers posed by bacterial infections, and there was a general lack of knowledge of internal anatomy. This lack of knowledge was due in large part to a taboo against human dissection — and there were similar taboos against cutting into the skin at all.

When Plato defends exercise as especially capable of promoting health, he thinks of himself as objecting to those doctors who incorporated drugs into a treatment plan for patients at all.

In the Timaeus, he encourages us to be like someone who “never allows his body to ever be at rest but keeps it moving” (88d).

Constant motion! We should be moving all the time. These motions shouldn’t be random, but should be “moderate.” The Greek word here is metriōs, and it literally means something like ‘measured’. So, these are orderly motions.

Why would Plato recommend this to us?

First, it makes sense when you consider what he thinks causes disease:

“For since the body is heated and cooled internally by the things that enter it, and since it is dried and moistened in turn by things outside of it, and since it experiences the changes that follow both of those motions, whenever someone delivers his body to these motions when it is in a state of rest, it is overpowered and destroyed” (88d).

In other words, our environment causes things to go in and out of the body. These things cause our body to undergo transformations, such as being dried and moistened. These transformations give rise to further transformations, which can cause our body to be diseased when they take place in a body that is at rest.

So, we need to exercise to ensure that our body is protected against disease-causing transformations.

You can think about it like this: when we’re idle and resting, there is a greater chance of our body becoming diseased due to environmental influences. We’re able to resist these influences more effectively when we’re moving.

When we begin to dive deeper into why Plato would think any of this is true, we begin to get into his second reason for preferring exercise: the motions we generate by ourselves are better than any other kind of motion.

He says this very explicitly: “motion that is caused by something else is worse” (89a).

The point is that when we use our own body to generate motion — when we engage in self-motion, in other words — we produce the best kind of motion. This is motion that is not dependent on anything else for its own cause.

This is important to Plato because he thinks that this motion resembles the rational motions that govern the whole cosmos. The cosmos moves itself, and it does so rationally, as I discussed in another post. At a general level, you can think of Plato saying that the motions that characterize the cosmos’ motions are rational and orderly.

(If you have a hard time imagining the cosmos moving, you can think of the way that we today know that the universe is expanding. That expansion is a kind of motion. Plato thinks that it isn’t expanding; it is moving circularly, in a perfectly orderly fashion.)

Just as the universe moves itself, we too can move ourselves. The resemblance between the universe’s motion and our self-motion makes our self-motion the best kind of motion that we could undergo.

So, we have two reasons for preferring exercise:

1. It wards off disease by protecting us against environmental influences that would be bad for us if they caught us when we are idle.

2. It is self-motion, and that’s the best kind of motion for us because it resembles the cosmos’ motion.

You might be wondering: ‘well, Plato recommends exercise because it is the best kind of motion — as opposed to what? What other options were on the table?’ And the answer is what I said earlier: drugs.

Drugs induce motions in us, and these motions are inferior to self-motion.

Plato has many reasons for distrusting the use of drugs. Many of these reasons deserve their own post. Plato, for instance, does not think that drugs can be plausibly thought of as doing anything good: diseases have life-cycles that they go through, and trying to cut those life-cycles short might only make the diseases worse. At most, he thinks it is worthwhile to take a drug only if you’re going to die anyway.

That approach leads Plato to prefer exercise as a way of preventing disease. Plato never recommends a cure for diseases because he thinks that when you’re sick, your best bet is to wait it out. Exercise prevents sickness; it does not cure disease.

But even apart from his distrust of drugs as capable of promoting health, he believes that the motions produced by drugs are inferior to self-motion and, therefore, inferior to the motions of exercise.

Drugs work by inducing motions/changes in us that then induce other changes, and so on. In theory, they should be able to induce motions that protect against the environment’s motions. But in practice, their motions are so bad that they are ineffective.

What we need is the best kind of motion: self-motion. So, we need to move our bodies. That’s why Plato thinks we should exercise.