John Venn

On April 4, 1923, John Venn, English mathematician (Venn Diagram), died at the age of 88. From the article:

"John Venn
John Venn Biography
Mathematician (c. 1834–c. 1923)
Mathematician John Venn developed George Boole's symbolic logic and is best known for Venn diagrams, which pictorially represent the relations between sets.
Synopsis
Mathematician John Venn was born in Hull, England, in 1834. A fellow of Caius College, Cambridge, he developed George Boole's symbolic logic, and in his Logic of Chance (1866) worked on the frequency theory of probability. He is best known for Venn diagrams, pictorial representations of the relations between sets that have become an oft-used tool in the teaching of mathematics and logic, among other concepts. Venn died in Cambridge in 1923.

Background and Education
John Venn was born on August 4, 1834, in Hull, England, to Martha Sykes and Reverend Henry Venn, a member of the Anglican clergy. The younger Venn received an education from tutors and at schools in Highgate and Islington, later earning his degree in mathematics in 1857 from Gonville and Caius College at Cambridge University. Having earned a fellowship there as well, Venn would establish a long-term career at his alma mater, becoming a lecturer in 1862 and being appointed college president more than four decades later.

By the end of the 1850s, following his father’s religious tradition, Venn was also ordained as a priest for the Church of England and did religious work for a short time before returning to Caius. He eventually resigned from the clergy in the 1880s, nonetheless continuing to remain involved in the church.

Venn Diagrams
In 1866, Venn published The Logic of Chance, a groundbreaking book that espoused the frequency theory of probability, offering that probability should be determined by how often concepts is forecast to occur as opposed to “educated” assumptions. Venn then further developed mathematician George Boole's theories in the 1881 work Symbolic Logic, in which he highlighted what would become known as Venn diagrams.

These graphics were pictorial representations of the relationships between sets, with similar diagrams having been used by Gottfried Leibniz and Leonhard Euler. Though quite complex in their orientation and application, Venn diagrams have become a trademark tool over the years in the teaching of introductory math and logic, as well as being used by popular media to illustrate relationships between groups and concepts. (For Venn’s 180th birthday, Google created a doodle illustrating said diagrams.)

Other Publications
Venn was elected to the Royal Society in 1883 and continued to publish other works, including The Principles of Empirical or Inductive Logic (1889) and volumes on the history of Cambridge and a list of its alumni, compiled with the aid of his son, John Archibald Venn.

John Venn died on April 4, 1923, in Cambridge, England, at the age of 90."