MACCH, ERNST. - German physicist and philosopher, born at Turany (Moravia) on 18 Feb. 1838, died at Haar (Munich) on 19 Feb. 1916. He taught physics at the Universities of Graz and Prague, and philosophy at Vienna. Famous for his "empirio-criticism," he is the founder and principal representative of modern criticism of science.
Principal works: *Die Mechanik in ihrer Entwick-lung historisch-kritisch dargestellt* (Leipzig 1883; Italian trans. by D. Gambioli, Rome 1908); *Populärwissenschaftliche Vorlesungen* (ibid. 1896; Italian trans. by A. Bongioanni, Turin 1900); *Die Analyse der Empfindungen, ecc.* (Jena 1900; Italian trans. by A. Vaccaro and C. Cessi, Turin 1903); *Erkenntnis und Irrtum* (Leipzig 1905; French trans. by M. Dufour, Paris 1908).
A pure positivist and empiricist, Mach reduces reality to sensation and denies any reality beyond experience. Science has merely practical value, as a means of adaptation in the struggle for existence; the use of concepts and language, the scientific method, the formulation of physical laws and hypotheses, are due exclusively to the principle of economy, by which each individual seeks to spare himself the greatest number of direct experiences with the aid of mental representations and symbols. Hypotheses that introduce metaphysical or physical entities must, however, be rejected, e.g., atomic theories and mechanism. Science is confined to the description of facts and the enunciation of laws; and these laws are valid only as simple restrictions that, guided by experience, prescribe the expectation of phenomena. Yet Mach escapes the sceptical consequences of human empiricism inasmuch as he makes sensation itself an absolute and, therefore, science a metaphysics of sensations.