The British logician John Venn was born at Drypool, Hull, the elder son of the Reverend Henry Venn, a prominent evangelical divine. After early education at Highgate and Islington proprietary schools, he entered Gonville and Caius College, Cambridge, in 1853. On graduating Sixth Wrangler in 1857, he became a fellow and remained on the foundation for sixty-six years, until his death. During the last twenty years of his residence he was also president of the college. Venn took orders in 1858 and served as a curate in parishes near London before returning to Cambridge as college lecturer in moral sciences in 1862. He married in 1867. In 1869 he was Hulsean lecturer and published thereafter a work titled On Some Characteristics of Belief (London, 1870), but contact with Henry Sidgwick and other Cambridge agnostics, plus the reading of Augustus De Morgan, George Boole, J. Austin, and J. S. Mill had the...