God has absolute lordship over all creation, because he created and sustains all things, and is their first principle and last end. He gives to all creatures their being, their nature, and their ends. He inscribes their purposes within them, and moves them towards those purposes. Creatures, on the other hand, can only have a relative and limited lordship over anything. Just as God is the universal cause so God is the universal Lord, while creatures are particular lords, whose lordship depends on God’s.

We can now alter the very nature of our bodies, but should we?