The Logic of Chance

John Venn, an English logician and philosopher, is best known for inventing Venn diagrams. These diagrams visually represent logical propositions and test the validity of syllogisms. Venn also made significant contributions to probability theory and symbolic logic.

In his work The Logic of Chance (1866), Venn presented the first systematic formulation of the frequency theory of probability. This theory posits that statements about probability predict the long-run frequency of an event's occurrence, rather than merely describing a person's belief about it. This contrasted with prevailing theories of the time. Venn's diagrams, introduced as a pedagogical tool, are now a standard in introductory logic courses.12