Philosophers continue to debate about David Hume's case against the rationality of belief in miracles. This article clarifies semantic, epistemological, and metaphysical questions addressed in the controversy. It also explains the main premises of Hume's argument and discusses criticisms of them. The article concludes that one's evaluation of Hume's argument will depend on one's views about (a) the definitions of ‘miracle’ and ‘natural law’; (b) the type of reasoning one ought to employ to determine the probability that a particular miracle claim is true; and (c) whether reasonable people proportion their beliefs about the occurrence of miracles to their evidence.