Letters 106.4

Now the good is active: for it is beneficial; and what is active is corporeal. The good stimulates the mind and, in a way, moulds and embraces that which is essential to the body. The goods of the body are bodily; so therefore must be the goods of the soul. For the soul, too, is corporeal.

Seneca, Letters to Lucilius 106.4, translated by Richard Mott Gummere