- ITELSON, GREGOR (1852–1926), philosopher. Itelson, who was born in Zhitomir, studied in St. Petersburg. He left Russia in 1884 and settled in Berlin. He was interested in the investigation of the philosophical foundations of the sciences and sought to reform the principles of logic. He had a direct influence on the representative philosophical and scientific thinkers of his time. In a particularly significant lecture delivered before the Second Philosophical Congress (Geneva, 1904), Itelson endeavored to liberate logic from its dependence on psychology and restore its lost autonomy by redefining it as "the science of objects in general, existent and nonexistent." This definition was directly opposed to the accepted view of logic as the science of thought. His conception was close to the views evolved at that time by Meinong, Husserl, and Couturat as a result of the influence of Bolzano. Itelson's theories drew him close to "the algebra of logic"; he also tried to find a logical basis for mathematics, which he defined as "the science of ordered objects." During the last years of his life Itelson taught at the Juedische Volkshochschule, Berlin. His extensive library was bequeathed to the Jewish National and University Library in Jerusalem. -BIBLIOGRAPHY: KS, 3 (1927), 242; Kantstudien, 31 (1926), 428–30; Revue de métaphysique et de morale (1904), 1037ff. (Samuel Hugo Bergman)
Encyclopedia Judaica. 1971.