The author argues that the human mind is a product of undirected, selective evolution that has occurred over several million years. He argues that, in order to understand the mind of current humans, it is essential to study the early history of humans, humanoids, and great apes. As an archaeologist, he feels that one can study the behavior of these earlier creatures through the traces left at various archaeological sites. Through studying the skulls and artifacts of these creatures, he argues one can deduce their brain size, their behaviors, and perhaps even their beliefs. These inferences include an understanding of why and how religion developed as human activities. This is theorizing on a grand scale.

There is much that is enjoyable about this volume. It is a fun read. Occasional unnecessary swipes at creationism, which he misunderstands, are minor annoyances that detract from his effort. A major problem, however, is his mistaken belief that cranial volume is a measure of brain size. The fact that cranial volume has not increased is not the critical issue for mental functioning. It is the enormous increase in the size of the cortex as a result of its folding. The difference between chimpanzees and humans in the cortex is not dramatic in terms of its thickness, but there is an enormous difference in its size. Folding permits a skull of the same volume to hold much more cerebral cortex. We cannot judge from archaeological data when this folding took place, but we do know how important it is for mental functioning. The author draws an analogy between a "cognitive" archaeologist and a detective. They both study observables and draw inferences that, one hopes, lead to correct insights. The "cognitive" archaeologist becomes a Sherlock Holmes studying the evolution of the human mind from its prehistorical relics.

The delight of this volume is in its glib drawing of conclusions from data as if they were unique interpretations. It is reminiscent of Holmes remarking to Watson in A Study in Scarlet that "You have been in Afghanistan, I perceive." When Holmes explains that Watson is a medical type, has the air of a military man, has a sun tan, and has an injured arm, it is obvious that he has been wounded in Afghanistan. Unfortunately, Watson may have good posture because his mother imposed it on him, may have injured his arm in a fall from a carriage, and may have enjoyed the sun in Italy. There are many explanations for observables. Some are more delightful than others; unfortunately, delight is not an epistemological criterion. Speculations are not hard evidence. A guess is not a fact. Despite these criticisms, the book is wonderful beach reading and is therefore recommended.