Karl Wolfgang Deutsch (21 July 1912 – 1 November 1992) was a social and political scientist from Prague. He was the Stanfield Professor of International Peace at Harvard University. From 1977 to 1987 he was the Director of Wissenschaftszentrum Berlin (International Institute for Comparative Social Research).
His work focused on the study of war and peace, nationalism, co-operation, and communication. He is also well known for his interest in introducing quantitative methods and formal system analysis and model-thinking into the field of political and social sciences and is one of the best known social scientists of the 20th century.
Born into a German-speaking family in Prague on July 21, 1912 when the city was part of the Austro-Hungarian Empire, Deutsch became a citizen of Czechoslovakia after World War I. His mother Maria Leopoldina Scharf Deutsch was a Social Democrat, and the first woman to be elected to the Czechoslovak parliament (1918) where she became known for her resistance to Nazism. His father Martin Morritz Deutsch owned an optical shop on Prague's Wenceslas Square and was also active in the Czechoslovak Social Democratic Worker's Party. His uncle Julius Deutsch was an important political leader in the Social Democratic Party of Austria.
Karl studied Law at the German University of Prague, where he graduated in 1934. He discontinued further studies as his overt anti-Nazi stance caused opposition by pro-Nazi students. Karl married his wife Ruth Slonitz in 1936, and after spending two years in England returned to Prague where due to his former Anti-Nazi activities, he could not return to the German University. He instead joined its Czech counterpart, the Charles University, where he obtained a law degree in international and canon law and a PhD in Political Sciences in 1938.
That same year, which saw the Munich Agreement allowing German troops to enter the Sudetenland, he and his wife did not return from a trip to the United States. In 1939 Deutsch obtained a scholarship to carry out advanced studies at Harvard University where he received a second PhD in political science in 1951.
During World War II he worked for the Office of Strategic Services and participated in the San Francisco conference that resulted in the creation of the United Nations in 1945. Deutsch taught at several universities; first at MIT from 1943 to 1956; then at Yale University until 1967; and again at Harvard until 1982. He served as Stanfield Professor of International Peace at Harvard, a position he held until his death.
Deutsch worked extensively on cybernetics, on the application of simulation and system dynamics models to the study of social, political, and economic problems, known as wicked problems. He built upon earlier efforts at world modeling such as those advanced and advocated by authors of the Club of Rome such as Limits to Growth by Donella Meadows, et al. (1972). He introduced new concepts such as security community to the literature.
He held several other prestigious positions; he was a member of the board of World Society Foundation in Zürich, Switzerland from 1984 onwards. He was also elected President of the American Political Science Association in 1969, of the International Political Science Association in 1976, and of the Society for General Systems Research in 1983. From 1977 to 1987, he was Director of the Social Science Research Center Berlin (Wissenschaftszentrum Berlin für Sozialforschung, WZB) in Berlin.
He died in Cambridge, Massachusetts on November 1, 1992. He has two daughters, Mary D. Edsall, a writer (wife of Thomas Edsall), and Margaret D. Carroll, an art historian, and three grandchildren, Alexandra Edsall, Sophia Carroll, and Samuel Carroll.