This paper presents a detailed reconstruction of Theophrastus’ account of human ontogeny, which is built around Aristotle’s notoriously difficult claim in Generation of Animals II 3 that “νοῦς alone enters from without.” I argue that this account (which is known to us via quotes from Theophrastus’ de Anima II and On Motion I) provides a viable alternative to the traditional trilemma between naturalist traducianism, creationism, and pre-existence, as well as offering an attractive but so far unappreciated interpretation of Aristotle’s account (...) of human ontogeny. More specifically, I argue that the extant evidence poses a challenge to the two dominant interpretations of “νοῦς from without” in the last decades: a dialectical one, according to which Aristotle ultimately rejects this claim, and a naturalizing one (often inspired by Alexander of Aphrodisias) that obliterates the essential difference between νοῦς and the other parts of the soul. (shrink)