What Mach Owes to Fechner and what he Made of it
Michael Heidelberger
In what follows, I would like to discuss Mach’s considerable debt to Gustav Theodor Fechner, the Leipzig physicist and founder of psychophysics. This is not the appropriate place to review the historical evidence of Mach’s strong dependence on Fechner – this has already been done elsewhere. Instead, I want to draw a systematic comparison between Mach’s and Fechner’s conceptions. It turns out that the major disagreement between Mach and Fechner is over the nature and reach of metaphysics and the relation of the different scientific disciplines to each other. I hasten to add that this is not a story of the brave and heroic anti-metaphysician Mach against the speculative panpsychist Fechner. As is usually the case, things are more complicated than that. In my talk I will try to reconstruct the essential features of Mach’s thought as ‘corrections’ or transformations of Fechner’s outlook. Such modifications were needed in order to account for changes in the relationship of scientific disciplines toward each other that had taken place in the meantime – specially Darwinism and the new psychology. In particular, I will deal with Mach’s antirealism, his conception of causality, his Elementenlehre, and his solution of the mind-body problem, all in relation to Fechner. In the final part, I will consider different conceptions of anti-metaphysics and show that, compared with Fechner’s views, Mach’s anti-metaphysics is in certain regards too restrictive for science. Speculative metaphysics is to be rejected, but we need a healthy dose of Fechnerian inductive metaphysics.