John Venn

John Venn was an English mathematician and logician who spent his career finding better ways to think about uncertainty and structure. In 1866 he published The Logic of Chance, a groundbreaking work that argued probability should rest on observed frequency rather than guesswork. Fifteen years later, in Symbolic Logic, he developed George Boole's theories further and introduced the diagrams that would outlive everything else he wrote. The overlapping circles made abstract relationships concrete, and they spread across disciplines — logic, set theory, probability, computer science. He was electe…