Of the irrational part, again, one division seems to be common to all things that live, and to be possessed by plants⁠—I mean that which causes nutrition and growth; for we must assume that all things that take nourishment have a faculty of this kind, even when they are embryos, and have the same faculty when they are full grown; at least, this is more reasonable than to suppose that they then have a different one.

The excellence of this faculty, then, is plainly one that man shares with other beings, and not specifically human.