Abstract

This paper will focus on a famous nineteenth century debate over the physiology of perception between Ewald Hering and Hermann von Helmholtz. This debate is often explained as a contest between empiricism (Helmholtz) and nativism (Hering) about perception. I will argue that this is only part of the picture. Hering was a pioneer of Lamarckian explanations, arguing for an early version of the biogenetic law. Hering explains physical processes, including perception, in terms of ‘organic memory’ that is supported by ‘vital forces’ located throughout the body. Helmholtz, on the other hand, argues that vital forces are in direct conflict with the results he and others proved in the 1840s and 50s on the conservation of force. The battleground of the debate was the interpretation of Johannes Müller’s ‘law of specific nerve energies’, which Hering interpreted in terms of vital forces, and Helmholtz interpreted using a naturalized neo-Kantian approach. In the end, the debate revealed deep fissures in nineteenth century accounts of scientific explanation, as well as in the conception of how physiology, psychology, physics, and philosophy are related.