From the Same ms. — Ibid. 1335 D
Φύσις (nature) is so called from τὸ πεφυκέναι (to be born). The first substance is everything which subsists by itself, as a stone is called a substance. The second is a substance capable of increase, as a plant grows and decays. The third is animated and sentient substance, as animal, horse. The fourth is animate, sentient, rational substance, as man. Wherefore each one of us is made as consisting of all, having an immaterial soul and a mind, which is the image of God.
Source: Fragments (New Advent)