Helmholtz criticized: Mach, Riehl, Laas, James

Michael Heidelberger

Universität Tübingen

The critics of Helmholtz that are usually treated in existing expositions of Helmholtz’s philosophy are mostly Kantians who are relatively unknown and are justly forgotten for their contributions to philosophy. Yet there are also more famous critics of Helmholtz whose criticism is, however, almost unknown or rarely dealt with. My goal in this paper is to make this criticism more known and to discuss it in relation to later philosophy of science. There is first Ernst Mach who wrote an enthusiastic review of Helmholtz’s On the Sensations of Tone and a little later a popularized account of it for musicians. Here and in the later Analysis of sensations Mach criticized two attitudes in Helmholtz’s account: on the one hand to reduce living phenomena to physics without taking into account the relative autonomy of biological mechanisms and on the other hand to neglect the primacy of psychology for the physiological analysis of sensation. Alois Riehl was a philosopher who tried to transform Kant’s theoretical philosophy into a viable critical realism. The most important component of his critique concerned Helmholtz’s conception and use of the principle of causality. According to Riehl, Helmholtz’s account of the transition from sensation to perception through causal reasoning commits two grave errors: a mistake in presupposing the causal principle as innate and a mistake in the way the principle is actually applied. Perceptions cannot be the result of a causal inference out of sensations. The application of the causality principle cannot lead us any further than our sensation and never to causes outside of sensation, as Helmholtz claimed. In the same vein, Riehl criticized Helmholtz’s claim that our experimental interaction with the world through our bodily movements can result in a transformation of non-spatial sensations into spatial perceptions. The positivist philosopher Ernst Laas also criticized Helmholtz’s usage of the causality principle. His most important criticism, however, concerned Helmholtz’s conception of geometry. He compared it to Mill’s empiricist philosophy of arithmetic and saw Helmholtz’s connection of spatial laws with the physical behavior of rigid bodies as akin to the way Mill tried to derive the laws of arithmetic from the behavior of concrete objects. William James, although he took Helmholtz Physiological Optics as “one of the four or five greatest monuments of human genius in the scientific line”, found grave fault in Helmholtz’s “empiricism” and defended “nativism” instead. Similar to Riehl, James could not understand how spatial qualities possibly could arise out of non-spatial ones as Helmholtz claimed. Instead, James saw the real problem in the way how we can arrive at a unitary objective space by summing up our diverse sensible space-experiences together. In conclusion, I will try to show how all this relates to the picture that Moritz Schlick gave us of Helmholtz in the commentaries to his edition (with Paul Hertz) of Helmholtz’s writings. It seems that Schlick was aware of many of the critical points that were raised by Helmholtz’s critics as described here.