Abstract

In this paper I examine Aristotle's account of sexual difference in Generation of Animals, arguing that Aristotle conceives of the production of males as the result of a successful teleological process, while he sees the production of females as due to material forces that defeat the norms of nature. My suggestion is that Aristotle endorses what I call the "degrees of perfection" model. I challenge Devin Henry's attempt to argue that Aristotle explains sex determination exclusively with reference to material necessity (in particular, levels of "vital heat" in the male semen), for Aristotle's notion of "sufficient" or "deficient" vital heat is itself teleological. If, as Aristotle is aware, male and female embryos appear with approximately equal frequency in most species, how, in light of Physics II, can he conceive of the former as in accordance with nature, and the latter as somehow contrary to nature? My proposal is that Aristotle's notion of what happens usually (ως επì τò πoλυ) is bifurcated: the usual need not be more frequent.