John Venn is most famous for his development of diagrams, later named after him, that depict relationships between sets. Although Gottfried Wilhelm von Liebniz and Leonhard Euler had used similar diagrams, Venn's were considered more descriptive and easier to understand. He also helped to develop George Boole's system of mathematical logic.

Venn was born in Hull, England on August 4, 1834, a descendant of a long line of Church of England evangelicals. He received his early education at two schools in London, at Highgate and Islington, but historical records indicate that either he was so poor a student or the schools were so incompetent that he was ill prepared for college. Nevertheless, he entered Gonville and Caius College at Cambridge in 1853 and earned a degree in mathematics there in 1857. The school made him a fellow upon graduation--he would retain that status for the rest of his life.

Becoming a priest...