Aristotle’s theory of seed: seeking a unified account

Aristotle’s theory of seed has occupied a very important place in the history of ancient embryology and medicine. Previous studies have overemphasized, in light of the APo. II method, Aristotle’s definition of seed as male semen. In this paper, I wish to show that there are at least three independent definitions of seed working in Aristotle’s Generation of Animals: seed as male semen, seed as female menstruation and seed as embryo. Those three definitions are mutually exclusive on the one hand, but on the other hand, they are also capable of being unified into one Aristotelian account, which can help us understand better Aristotle’s theory of seed. Keywords: Aristotle, theory of seed, animal, generation.