 Plato thought of human souls as distinct substances from their bodies, capable of existing separately and being reincarnated. The late ancient Platonists retained this dualism and aimed so far as possible even in their mortal lives to release their souls from their bodies and find union with the One. By contrast, for Aristotle the soul is the form of a living body, that which accounts for its life functions, just as the form of a non-living thing—the form of stoneness in a stone—accounts for its being the sort of thing it is. A plant, then, grows and goes through its life cycle in virtue of its vegetative soul. A non-human animal’s soul is not just vegetative but also sensitive: it accounts for the animal’s ability to move and to perceive with its senses. The human soul accounts for all these capabilities, and it also has intellect: it can think intellectually about universals. If the soul is the form of a body, survival independently of the body would seem impossible in principle. There are, however, passages in Aristotle’s On the Soul (especially 430a [Chapter 5]) that suggest that the intellect is imperishable, but they probably are not intended to refer to individual human souls.