The Private Parts of Animals: Aristotle on the Teleology of Sexual Difference

In this paper I examine Aristotle\u27s 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\u27s 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\u27s 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\u27s notion of what happens usually (ως επì τò πoλυ) is bifurcated: the usual need not be more frequent