In this fascinating book, William R. Uttal raises the possibility that, however much we learn about the anatomy and physiology of the brain and psychology, we may never be able to cross the final bridge explaining how the mind is produced by the brain. Three main classes of mind-brain theory are considered and rejected: field theories, because they are based on a superficial analogy; single cell theories, because they emerge from a massive uncontrolled experimental program; and neural net theories, because they are constrained by combinatorial complexity. To support his argument, Uttal explores the empirical and conceptual foundations of these theoretical approaches and identifies flaws in their fundamental logic. The author concludes that the problems preventing solution of the mind-brain problem are intractable, yet well within the confines of natural science.