Carl Joachim Friedrich was a German-American professor and political theorist. He taught alternately at Harvard and Heidelberg until his retirement in 1971. His writings on state and constitutional theory, constitutionalism and government made him one of the world's leading political scientists in the post-World War II period. He is one of the most influential scholars of totalitarianism.
Carl Gustav Jung was a Swiss psychiatrist and psychoanalyst who founded analytical psychology. Jung's work has been influential in the fields of psychiatry, anthropology, archaeology, literature, philosophy, psychology, and religious studies. He worked as a research scientist at the Burghölzli psychiatric hospital, in Zurich, under Eugen Bleuler. Jung established himself as an influential mind of his time, developing a friendship with Sigmund Freud, founder of psychoanalysis, conducting a lengthy correspondence, paramount to their joint vision of human psychology. He is regarded as one of the most influential psychologists in history.
Carl Linnaeus, also known after his ennoblement in 1761 as Carl von Linné, was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern taxonomy". Many of his writings were in Latin; his name is rendered in Latin as Carolus Linnæus and, after his 1761 ennoblement, as Carolus a Linné.
Carl Ludwig Schleich was a German surgeon and writer. He is best known for his contribution to clinical anesthesia. In addition, he was also a philosopher, poet and painter.
Carl Mayer was an Austrian screenwriter who wrote or co-wrote the screenplays to The Cabinet of Dr. Caligari (1920), The Head of Janus (1920), The Haunted Castle (1921), Der Letzte Mann (1924), Tartuffe (1926), Sunrise: A Song of Two Humans (1927), and 4 Devils (1928), most of them being films directed by F. W. Murnau. Mayer was a fundamental figure in the dramatic and narrative establishment of both German expressionist cinema and Kammerspielfilm.