In this deep rethinking of Aristotle's work, Abraham P. Bos argues that scholarship on Aristotle's philosophy has erred since antiquity in denying the connection between his theology and his doctrine of reproduction and life in the earthly sphere. Beginning with an analysis of God's role in the Aristotelian system, Bos explores how this relates to other elements of his philosophy, especially to his theory of reproduction. The argument he develops is that in talking about the cosmos, Aristotle rejected Plato's metaphor of artisanal production by a divine Demiurge in favor of a biotic metaphor based on the transmission of life in reproduction, in which pneuma--not breath as it is often interpreted but the life-bearing spirit in animals and plants--plays a key and sustaining role as the vital principle in all that lives. In making this case, he defends the authenticity of the treatises De Mundo and De Spiritu as Aristotle's, and demonstrates Aristotle's works as a unified system that sharply and comprehensively refutes Plato's, and in particular replaces Plato's doctrine of the soul with a theory in which the soul is clearly distinguished from the intellect.