Letters 121.10

But some object as follows: “According to your account, one’s constitution consists of a ruling power in the soul which has a certain relation towards the body. But how can a child comprehend this intricate and subtle principle, which I can scarcely explain even to you? All living creatures should be born logicians, so as to understand a definition which is obscure to the majority of Roman citizens!”

Seneca, Letters to Lucilius 121.10, translated by Richard Mott Gummere