Thomas Bayes

Thomas Bayes was an English Presbyterian minister and mathematician who served a congregation at Tunbridge Wells. His essay on a problem in the doctrine of chances, published after his death by Richard Price in 1763, addressed how to infer the probability of a cause from observed events. The rule for updating probabilities in the light of evidence now carries his name and underlies Bayesian epistemology, statistics and decision theory, although its modern general form owes much to Laplace.

Key ideas

• Probabilities of hypotheses can be inferred from observed outcomes.
• Belief should be updated by conditioning on new evidence.
• Prior probabilities combine with the likelihood of the evidence to yield posterior probabilities.
• Newton's method of fluxions can be defended against Berkeley's criticisms.

Major works

• Divine Benevolence (1731)
• An Introduction to the Doctrine of Fluxions (1736)
• "An Essay towards solving a Problem in the Doctrine of Chances" (1763, posthumous)

In the conversation

• Debate Not every coherent prior is rational: subjective Bayesianism is far too permissive Derek Hollis · 5 replies
• Discussion Affirming the consequent on a hospital ward Omar Ragab · 5 replies
• Discussion Thirty-four years of anxious calls about screening results, and base rates still trip me up Alistair Gow · 5 replies

In the Journal

• Journal How much should one result change your mind? Thinking in degrees of belief Wanjiru Njenga · 0 replies