In the 1787 Transcendental Deduction of the Categories Kant indicates the only possible ways by which one can account for a necessary agreement of experience with the concepts of its objects (B166), using analogies between modes of explanation and biological theories about the origin of life. He endorses epigenesis as a model for his system of pure reason (B167). This paper examines various interpretive claims about the meaning of this theory of generation and its significance for Kant’s philosophy (Section 1), (...) showing that, after his Critical shift in perspective, in 1775/77 Kant already combined preformed elements and their purposively oriented formation by natural forces (Section 2). Contrary to the standard view, Kant’s theory of race appears to constitute the background to assess Blumenbach’s later (1799/1781) shift to epigenesis after supporting Haller’s preformism (Section 3). In Section 4, I argue that the ground of affinity between epigenesis and formal idealism rests in tracing the first origin of these conformities: external a posteriori climate conditions and predisposed germs and dispositions within the generative power of the human body; and external a posteriori experience and spontaneous a priori concepts of its objects, within pure sensory intuiting and pure thinking. In both cases the external empirical conditions would function as occasioning propelling factors affecting internal pre-established forms of generation. (shrink)