John Earman has written a wonderful book that shows the value of using the precision of probability theory to bring clarity to a murky issue. Long have certain philosophers marvelled at David Hume's essay, "On Miracles," supposing it to be an original and creative refutation of believing in miracles. Earman shows that Hume's arguments are neither original nor sound at establishing his pessimistic outlook on miracles. Moreover, using probability calculus, Earman is able to establish clearly that Hume's argument is a failure. In fact, Earman shows that many of Hume's contemporaries were familiar with probabilistic reasoning and were able to demonstrate Hume was wrong within in his own lifetime. So, not only was Hume wrong, but his failure cannot be attributed to the lack of development of inductive reasoning in his time. Earman works hard trying to understand what exactly Hume meant by examining Hume's personal letters and the developments of Hume's essay as it was published in various editions. After several attempts to read Hume charitably, Earman finds Hume's application of probabilistic reasoning is muddled and confused, at best. Furthermore, Earman shows that if Hume was right, this would spell disaster for inductive reasoning that confirms (or disconfirms) scientific reasoning. Those who endorse Hume's argument against miracles are supporting a line of reasoning that would eqully undermine science.
Earman's book is commendable for a number of reasons. First, it is a first-rate work in philosophy that is written clearly. Earman's rigor coupled with his readable prose make for a rewarding study. Second, this book makes significant contribution to Humean scholarship where Earman convincingly argues for various ways to interpret Hume, which he substantiates with cross-referencing the work of Hume and his interaction with his contemporaries. Third, the book is a powerful lesson in probability theory (especially Bayesianism). Some background in probabilistic reasoning may be needed to understand parts of the book, but even a cursory knowledge of probability theory will be nourished by Earman's work. Fourth, this book puts forward some substantial theories relevant to philosophy of religion, especially the nature of miracles. Fifth, the second half of the book is filled with important sources on the 18th century deist controversy, which are invaluable to studying probability and confirmation of miraculous events by eyewitness testimony. For those who find these issues to be important and wish to get a better handle on how to think clearly through these issues, this book will be a welcome piece of scholarship.