Materialism, Lebenskraft and the limits of science: metaphysical vitalism in post-Kantian scenarios

Abstract

Kant's legacy in the history of life sciences has notoriously included a critique of the use of soul and ‘vital force’ (Lebenskraft). In this paper I focus on a less-known side of this legacy, i.e. Kant's late critique of vital materialism and its impact on nineteenth-century German science and philosophy. I show that Kant considered materialism as a kind of metaphysical hypothesis since the 1760s and pointed out that it was empirically impossible to distinguish it from different kinds of hypotheses (such as monadology). I focus on Kant's late essay on Samuel Sömmering (1796), arguing that the critical rejection of materialism and the notion of Lebenskraft belonged to an anti-reductive program for life sciences. I maintain that Kant's views influenced Alexander von Humboldt's turn concerning vitalism in the late 1790s and the anti-metaphysical and physicalist epistemology of Hermann von Helmholtz. I follow this Kantian legacy in the works of Friedrich Lange, Emil du Bois-Reymond and Erich Adickes. Finally, I argue that this tradition provides a vantage point to reconsider contemporary debates over materialism and panpsychism.