Rudolf Ivanovich Abel, real name William August Fisher, was a Soviet intelligence officer. He adopted his alias when arrested on charges of conspiracy by the FBI in 1957.
Rudolf Arnheim was a German-born writer, art and film theorist, and perceptual psychologist. He learned Gestalt psychology from studying under Max Wertheimer and Wolfgang Köhler at the University of Berlin and applied it to art.
Rudolf Bahro was a dissident from East Germany who, since his death, has been recognised as a philosopher, political figure and author. Bahro was a leader of the West German party The Greens, but became disenchanted with its political organization, left the party and explored spiritual approaches to sustainability.
Rudolf Borchardt was a German essayist, poet and cultural historian. He is perhaps best known for translating Dante's Divine Comedy into his own type of German language. Ernst Schmidt called Borchardt "one of the most problematic figures in early twentieth-century European cultural history" and "one of Germany's finest poets."