“Stahl Was Often Closer to the Truth”: Kant’s Second Thoughts on Animism, Monadology, and Hylozoism

In the Dreams of a Spirit-Seer, Elucidated by Dreams of Metaphysics (1766), Kant remarks that Stahl, with his admission of immaterial forces for the explanation of organisms, was “closer to the truth than Hoffmann and Boerhaave, to name but a few,” although the latter adopted a “more philosophical method.” This puzzling statement is very significant for the understanding of Kant’s reception of animism, as it documents Kant’s reaction to the issues raised by the Leibniz-Stahl controversy and his striking preference for Stahl’s nonmechanistic account of organisms. Kant agrees with Stahl that organisms suggest the existence of immaterial thinking beings, but at the same time, the example of this speculative hypothesis leads him to question the explanatory power of metaphysical hypotheses in natural philosophy in general, as well as the possibility of empirically distinguishing among different hypotheses, such as monadology, materialism, and hylozoism. After the analysis of Kant’s skeptical conclusions in the Dreams of a Spirit-Seer, I discuss how this earlier connection of medicine, life sciences, and metaphysics leaves traces in Kant’s later work, by analyzing Kant’s discussion of Samuel Sömmering’s claim that matter “can be animated” in On the Organ of the Soul (1796) and the preliminary drafts for this essay.