John Venn
2
John Venn's mother, Martha Sykes, came from Swanland near Hull and died while he was still quite a young boy. 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. The Rev Henry Venn, himself a fellow of Queen's, 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. They successfully campaigned for the abolition of slavery, advocated prison reform and the prevention of cruel sports, and supported missionary work abroad.
It was not only Venn's grandfather who played a prominent role in the evangelical Christian movement, for so did his father the Rev Henry Venn. 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. The Rev Henry Venn became secretary to this Society in 1841 and in order to carry out his duties moved to Highgate near London. He held this position until his death in 1873.
As might be expected from his family background, John was very strictly brought up, and there was never any thought other than that he would follow the family tradition into the priesthood. He attended first Sir Roger Cholmley's School in Highgate, then the private Islington Preparatory School.
When he entered Gonville and Caius College Cambridge in October 1853 he had:-
... so slight an acquaintance with books of any kind that he may be said to have begun there his knowledge of literature.
Having been awarded a mathematics scholarship in his second year of study, he graduated as sixth Wrangler in the Mathematical Tripos of 1857, meaning that he was ranked in the sixth place out of those students who were awarded a First Class degree in mathematics. He was elected a Fellow of Gonville and Caius College shortly after graduating, and two years later was ordained a priest. In fact the year after his graduation, in 1858, he had been ordained a deacon at Ely, then after his ordination as a priest he had served as a curate first at Cheshunt, Hertfordshire, and then for a year as a curate at Mortlake, Surrey.
In 1862 he returned to Cambridge University as a lecturer in Moral Science, studying and teaching logic and probability theory. He had already become interested logic, philosophy and metaphysics, reading the treatises of De Morgan, Boole, John Austin, and John Stuart Mill. Back at Cambridge he now found interests in common with many academics such as Todhunter. He also played a large role in developing the Moral Sciences Tripos over many years. He lectured and examined the Tripos, developing a friendly atmosphere bet
ween the lecturers and the students.
Venn extended Boole's mathematical logic and is best known to mathematicians and logicians for his diagrammatic way of representing sets, and their unions and intersections. He considered three discs R, S, and T as typical subsets of a set U. The intersections of these discs and their complements divide U into 8 non-overlapping regions, the unions of which give 256 different Boolean combinations of the original sets R, S, T.