The whole world is represented by the figure of a tree, of which the seeds and roots are the first indeterminate matter, the leaves the accidents, the twigs and branches corruptible creatures, the blossoms the rational soul, and the fruit pure spirits or angels.
23 that they have been begotten again, not of corruptible seed, but of incorruptible through the word of God.
The scholastic distinctions between corruptible and incorruptible substances, between absolute gravity and absolute levity, between natural and violent motions, if they did not wholly disappear from scientific phraseology, ceased thenceforward to hold the place of honour in the controversies of the learned.
Severus laid such stress on the human infirmities of Christ as proving that His body was like ours, created and corruptible (09ap-rov) that his opponents dubbed him and his followers Phthartolatrae - worshippers of the corruptible.2 The school of Themistius of Alexandria extended the argument to Christ's human soul, which they said was, like ours, limited in knowledge.
Moreover, though each natural substance is corruptible (40apr6v), species is eternal (&t&ov), because there was always some individual of it to continue its original essence (expressed by the imperfect tense in TO TI Etvae), which is ungenerated and incorruptible; the natural world therefore is eternal; and nature is for ever aiming at an eternal propagation, by efficient acting on matter, of essence as end.