Thomas Bayes

Thomas Bayes (c. 1701–1761) was an English statistician, philosopher, and Presbyterian minister who formulated the theorem that bears his name — though he never published it during his lifetime. His essay An Essay towards solving a Problem in the Doctrine of Chances (1763), edited and published posthumously by Richard Price, established the mathematical rule for updating probabilities in light of new evidence, thereby laying the foundation for Bayesian inference. Bayes's own motivations remain partly obscure: he was concerned with the theological problem of inductive reasoning — how evidence for design in nature could support belief in a divine creator — and his mathematical work was in service of this broader epistemological project. The irony that his theorem is now the dominant framework for secular probabilistic reasoning, from spam filters to machine learning, would likely have surprised him.