Bayes, Thomas, 1702–61, English clergyman and mathematician. The son of a Nonconformist minister, he was privately educated and earned his livelihood as a minister to the Nonconformist community at Tunbridge Wells. Although he wrote on theology, e.g., *Divine Benevolence* (1731), Bayes is best known for his two mathematical works, *Introduction to the Doctrine of Fluxions* (1736), a defense of the logical foundations of Newton's calculus against the attack of Bishop Berkeley, and "Essay Towards Solving a Problem in the Doctrine of Chances" (1763). The latter, a pioneering work, attempts to establish that the rule for determining the probability of an event is the same whether or not anything is known antecedently to any trials or observations concerning the event. Bayes's theorum calculates the probability of a hypothesis in the light of new evidence, producing a revised (posterior) probability.

See study by S. B. McGrayne (2011).

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