Conrad Hal Waddington CBE FRS FRSE (8 November 1905 – 26 September 1975) was a British developmental biologist, paleontologist, geneticist, embryologist and philosopher who laid the foundations for systems biology, epigenetics, and evolutionary developmental biology. Waddington had wide interests that included poetry and painting, as well as left-wing political leanings. In his book The Scientific Attitude (1941), he touched on political topics such as central planning, and praised Marxism as a "profound scientific philosophy".