Engines of Logic is a thoroughly enjoyable mix of biographical portraits and theoretical mathematics. If, in places, the mathematical/logical ideas are not so clearly developed, we don't fault the author. In a book of this size (slim) and scope (broad), one can only hope to find a decent overview of a particular subject matter. Engines of Logic is more than decent; it is highly entertaining, informative, and thought-provoking. The great pleasure Davis took in writing it springs from every page. Davis is a fine guide through some very abstruse mathematical and computer science fields -- to which he himself has been a significant contributor. This book is a first-rate piece of popular science.