Ivan Petrovich Pavlov (Russian: Ива́н Петро́вич Па́влов; IPA: [ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf]; 26 September [O.S. 14 September] 1849 – 27 February 1936) was a Russian physiologist known primarily for his work in classical conditioning. From his childhood days Pavlov demonstrated intellectual brilliance along with an unusual energy which he named "the instinct for research". Inspired by the progressive ideas which D. I. Pisarev, the most eminent of the Russian literary critics of the 1860s, and I. M. Sechenov, the father of Russian physiology, were spreading, Pavlov abandoned his religious career and...