Porphyry: To Gaurus on How Embryos are Ensouled and On What is in Our Power (Ancient Commentators on Aristotle)

Concerning embryos, Porphyry takes an original view on issues that had been left undecided by his teacher Plotinus and earlier by the doctor Galen. What role is played in the development of the embryo by the souls or the natures of the father, of the mother, of the embryo, or of the whole world? Porphyry's detailed answer, in contrast to Aristotle's, gives a big role to the soul and to the nature of the mother, without, however, abandoning Aristotle's view that the mother supplies no seed. In the fragments of "On What is in Our Power", "Porphyry" discusses Plato's idea that we choose each of our incarnations, and so are responsible for what happens in our lives.