This procedure of revising inferences about old information as new information arrives springs from a philosophical viewpoint that makes Bayes’s contribution strikingly modern: in a dynamic world, there is no single answer under conditions of uncertainty. The mathematician A.F.M. Smith has summed it up well: “Any approach to scientific inference which seeks to legitimise an answer in response to complex uncertainty is, for me, a totalitarian parody of a would-be rational learning process.”24
