It wouldn’t seem like eating well would be an important part of the philosopher’s job, but indeed it is. Antoninus Pius, the adopted stepfather of Marcus Aurelius and one of the quietly great Roman Emperors, kept a simple diet so he could work from dawn to dusk with as few bathroom interruptions as possible—so he could be at the service of the people for longer.
In one of his letters, Seneca wrote that the better one eats, the less one needs to exercise, which then frees up valuable time for reading and thinking. Our keen edge, he said, is too often dulled by heavy eating and then wasted further as we drain our life-force in exercise trying to work it off.
In the moment, it’s easy to enjoy whatever treat is in front of you—or to grab that extra helping because it’s there. But what we are bad at calculating is what kind of person we’re going to feel like after. It’s like with drinking: it might make you friendlier at first, and then a real monster a few hours later. And the next day? Well then you won’t be good for anything.
An Athenian statesman once attended a dinner party put on by Plato. When he met his host again, he is reported to have said “Plato, your dinners are enjoyable not only when one is eating them, but on the morning after as well.” Moderation, discipline, knowing your body—these things are important because they help your mind. They help you as a person, and as a philosopher.
This doesn’t mean you must be an ascetic; that you should eat the same thing every day, that it should be stripped of the flavors you enjoy, that you can never indulge, that food can’t both be fuel and fun.
But to eat well, is to live well. To eat right, is to live rightly. And that is the goal.