ADLER, FRIEDRICH (1879- ), Austrian politician, was born in Vienna July 9, 1879, the son of Viktor Adler (q.v.). From 1907 to 1911 he was lecturer in physics at the University of Zürich, but he was soon immersed in politics. From 1911 to 1916 he was secretary of the Austrian Social Democratic Party and editor of the monthly Kampf. During the World War he was in close sympathy with the Socialists of the Left. In despair over the break-up of the International, as a protest against war and a sign of proletarian feeling against it, he shot the Austrian prime minister, Count Stiirgkh, on Oct. 21, 1916. On May 19, 1917 a special tribunal condemned him to death, but his sentence later was commuted to 18 years' imprisonment. He was, how ever, amnestied on Nov. 1, 1918. In 1919 he was elected to the National Assembly, and became vice-president of the committee of the Social Democratic Party and of the Union of the Social Democratic deputies. He became secretary of the International Working Union of Socialist Parties (the "2r International), and after its absorption in the Second International (which changed its name to "Labour and Socialist International" at Hamburg in 1923) became secretary of the latter body also.
Adler's chief works are: Die Erneuerung der Internationale (1918) ; Ernst Mach's Ueberwindung des mechanischen Materialismus (1918) ; Ortszeit, Systemszeit, Zonenzeit and das ausgezeichnete Bezugssystem der Electrodynamik, eine Untersuchung caber die Lorentzische and die Einsteinsche Kinematik (1920).
See Friedrich Adler vor dem Ausnahmegericht (1923).