In the wake of Timothy Lenoir’s seminal study of late eighteenth-century German life-science, Kant’s teleology has often been interpreted as providing theoretical foundations for the view that biology is a special science. Lenoir’s thesis has recently been rejected. Robert Richards and John Zammito have argued that Kant never took biology to be a science. In the present paper, I argue that the interpretative perspective of Lenoir, Richards and Zammito is incomplete. These interpreters reconstruct Kant’s teleology in relation to developments in late eighteenth-century biology. I show that in order to fully understand Kant’s teleology we must take into account the little known teleological and biological views of Christian Wolff and his rationalist followers. Through establishing the historical importance of Wolffian teleology, we gain novel insight into various important methodological and philosophical debates that surround eighteenth-century German biology. This, in turn, will allow us to give a more balanced account of the relevance of Kant’s teleology in the history of biology.

First, I show that Wolff developed an account of teleological inference in the life sciences that was based on an ideal of demonstrative science. For Wolff, propositions specifying the functions of organisms are deductively derived from theological truths. Second, I reconstruct the influence of Wolffian teleology on the philosophical and scientific works of Reimarus and Crusius. I show that they modified Wolffian teleology partly because it was not compatible with theories of (organic) self-organization developed by Buffon, Needham and Trembley. The clash between Wolffian teleology and theories of practicing biologists gave rise to a probabilistic account of teleological hypotheses and a surge of metaphysical debates on the possible vitalist or materialist implications of biology. Third, and finally, I show that the sketched historical context allows us to give a more balanced account of the historical relevance of Kant’s teleology. On the one hand, Kant provided a small step in establishing biology as a science by strictly demarcating biology from metaphysical positions. On the other hand, Kant’s preoccupation with questions of demarcation led him to adopt a thoroughly anti-realist view on natural purposiveness that was difficult to reconcile with the views and intentions of eighteenth-century practicing life scientists.