John Venn FRS (Hull,Yorkshire, August 4, 1834 – Cambridge, April 4, 1923), was a British logician and philosopher, who is famous for the Venn diagrams, which are used in many fields, including set theory, probability, logic, statistics, and computer science.
John Venn's mother, Martha Sykes, came from Swanland near Hull, Yorkshire and died while John was still quite young. His father was the Rev Henry Venn who, at the time of John's birth, was the rector of the parish of Drypool near Hull. Henry Venn, himself a fellow of Queens', was from a family of distinction. His father, John's grandfather, was the Rev John Venn who had been the rector of Clapham in south London. He became the leader of the Clapham Sect, a group of evangelical Christians centred on his church who campaigned for prison reform and the abolition of slavery and cruel sports.
Venn's father also played a prominent role in the evangelical Christian movement. The Society for Missions in Africa and the East was founded by evangelical clergy of the Church of England in 1799 and in 1812 it was renamed the Church Missionary Society for Africa and the East. Venn's father was secretary to this Society from 1841. He moved to Highgate near London in order to carry out his duties. He held this position until his death in 1873.
John was brought up strictly. It was expected that he would follow the family tradition into the Christian ministry. After Highgate School, Venn entered Gonville and Caius College, Cambridge, in 1853. He graduated in 1857 and shortly afterwards he was elected a fellow of the college. He was ordained as a deacon at Ely in 1858 and became a priest in 1859. In 1862 he returned to Cambridge as a lecturer in moral sciences.
Venn's main area of interest was logic and he published three texts on the subject. He wrote The Logic of Chance which introduced the frequency interpretation of probability in 1866, Symbolic Logic which introduced the Venn diagrams in 1881, and The Principles of Empirical Logic in 1889.
In 1883, Venn was elected to the Royal Society. In 1897, he wrote a history of his college, called The Biographical History of Gonville and Caius College,1349–1897. He commenced a compilation of biographical notes of the alumni of Cambridge University, a work which was continued by his son, John Archibald Venn (1883-1958) and published as Alumni Cantabrigienses in 10 volumes from 1922-1953.