Chapman Cohen (1868-1954) was an English atheist and secularist writer and lecturer. He was the elder son of Enoch Cohen, a Jewish confectioner, and his wife, Deborah (nee Barnett). He attended a local elementary school but was otherwise self-educated. He had read Spinoza, Locke, Hume, Berkeley, and Plato by the time he was eighteen. He moved to London in 1889. He soon joined the National Secular Society and was in demand as a lecturer, delivering over 200 lectures a year. He was elected vice-president in 1895. In 1898 he became assistant editor of G. W. Foote's Freethinker, and after Foote's death in 1915 he was appointed both editor of the Freethinker and president of the National Secular Society. A fine organiser, Cohen built up the society in the inter-war years, but many members felt he had stayed on too long, and in 1949 he was persuaded to resign as president. He was editor of the Freethinker until 1951. His works include: Determinism; or, Free-Will? (1919), Religion and Sex: Studies in the Pathology of Religious Development (1919) and Theism; or, Atheism: The Great Alternative (1921).