Eugen Kogon (2 February 1903 – 24 December 1987) was a German historian and Nazi concentration camp survivor. A well-known Christian opponent of the Nazi Party, Kogon was arrested more than once and spent six years at Buchenwald concentration camp. Known in Germany as a journalist, sociologist, political scientist, author, and politician, he went on to be considered one of the "intellectual fathers" of both West Germany and European integration. His 1946 book The Theory and Practice of Hell still stands as a basic reference on Nazi crimes.