My topic is the fundamental Aristotelian division between the animate and the inanimate. In particular, I discuss the transformation that occurs when an inanimate body comes to be ensouled. When nutriment is transformed into flesh it is first changed into blood. I argue that blood is unique in being, at one and the same time, both animate and inanimate; it is inanimate nutriment in actuality (or in activity) and animate flesh in potentiality (or in capacity). I provide a detailed exposition (...) of these manners of being (covering individual substances, artifacts, and mixtures), apply these insights to the case of blood, and then argue that blood's curious status is central to understanding hylomorphism in living organisms. (shrink)