Spinoza’s rejection of Aristotelian final causation seems to create a difficulty for his account of individuation. If causation is indeed blind, how do finite modes come to assume complex, differentiated forms? And why do we find in nature a great regularity of such forms? Several recent commentators have proposed that Spinoza maintains something of the Aristotelian conception of causation where the formal essences of individuals guide the process of individuation toward certain desirable outcomes. But this sort of approach introduces other (...) difficulties that threaten to undermine Spinoza’s naturalistic framework and his ontology of immanence. This paper outlines a mechanistic and probabilistic account of individuation whereby modes are individuated by entering into relations that increase their mutual power of enduring. Together with conatus as the principle of individuation, this mechanistic account suffices to explain the individuation of finite bodies without introducing additional kinds of causation into Spinoza’s philosophy. (shrink)