Thein provides a detailed analysis of Aristotle’s analogy between “the phusis in the pneuma” and “the element of the stars” in Aristotle’s GA (736b29–737a7). With the help of several passages in GA which discuss the role of pneuma in the generation of living beings, as well as passages of De caelo, where the first body is presented as an animate, self-moving but soulless entity, Thein makes the case that the key to the analogy lies in the shared link between motion and animation, a link which, in these two cases only, does not require the actual presence of the soul.