Ernst Mach: Physicist and Philosopher [Book Review]
Abstract
Although Mach insisted that he was a scientist, not a philosopher, many of his ideas were genuinely philosophical. This collection of essays indicates, among other matters of mathematical and scientific interest, how such ideas grew from Mach's work and something of their philosophical significance. In particular, discussions of Mach's experiments in aerodynamics and psychology show how he made physical phenomena observable and applied "causal" concepts to sensory processes. Having done this, Mach felt that he could hold a phenomenalism of neutral elements which are neither subjective nor objective. He thought that a unified science could be based on such elements and that he would then no longer have to change his conceptual frame in going from one discipline to another, as from "atoms" to "mind" in going from physics to biology. Young Albert Einstein was deeply impressed by Mach's attitude toward fundamental concepts. One essay discusses the influence on Einstein's theory of general relativity of Mach's Principle, i.e., Mach's substitution of the concept of motion with respect to the distant stars for the unobservable Newtonian concept of motion with respect to absolute space. A discussion of Mach's own use of the atomic theory illustrates his attitude toward theories and suggests that he was able to reject the atom because this concept is not particularly useful in the fields with which he was primarily concerned. An essay by editor Cohen on the implications of Mach's theory of knowledge argues that a phenomenalism of neutral elements collapses into mysticism, i.e., into a submergence of the ego in the universal consciousness. Also interesting is Philipp Frank's classification of Mach as an "Enlightment" philosopher, or one who criticizes the abuse of concepts. Just as the men of the eighteenth century Enlightenment opposed theological concepts in physics, so Mach opposed physical concepts in biology, thereby clearing science of old error to make way for new truth. Some biographical data and an extensive bibliography are appended, as well as an index of proper names.--L. G.