This chapter explores the ways issues around the soul came to prominence in ongoing intellectual debates about generation in the later Roman Empire. Neoplatonist philosophers and Christian theologians drew on, reworked and refuted, earlier understandings of human procreation, focusing increasingly on ‘ensoulment’, on questions of how, when and from where the rational, human soul came to be present in the new being. The emphasis is on the flexibility and contingency of much of the discussion, including among Christin theologians, and the relatively loose links between their theoretical discourse and church injunctions about behaviour. Late antiquity saw a basic change in the approach to fetal life, as the divinely provided human soul became more important to its constitution, but there was still much to work out and debate. While this shift helped to shore up the early Christian use of hostility to abortion, as also to infant exposure, as a sign of their own higher moral standards, it did so in a rather vague and diffuse way. The various developments seem less clear and connected than might have been expected.