Colin Blakemore is a physiologist at Cambridge who exhibits the special talent for popularization that one has come to associate with the English science tradition. These are the 1976 BBC Reith lectures on the brain, lavishly illustrated with historic art (such as Descartes' drawing of the reflex arc) and contemporary photos (the X-ray of a blood clot on the brain as revealed through the new technique of computerized axial tomography). Blakemore touches upon most of the ""hot"" topics--sleep, memory, perception, language, split-brain studies, schizophrenia--generally reviewing each topic historically. So, references range from the 19th-century phrenologists to the 20th-century lobotomists to the importance long ascribed to the ventricles (the channels for cerebrospinal fluid) as the seat of sensation or thought, Blakemore's interests naturally turn upon what neurophysiologists have been able to contribute to our understanding of mental processes: how cells in the visual system respond to straight edges or rectangles at set angles. . . or how memory may be coded chemically. But he does not ignore more speculative areas--the origin of language; brain evolution in relation to group selection. Indeed, he suggests that the roots of social discrimination today may lie in the brain's ability to classify and organize according to genetic similarities and dissimilarities in others. Something far beyond a competent summary of what nerve cell biologists are saying, this offers the broader, more provocative view of evolving mankind. As the author himself sagely concludes, ""The brain struggling to understand the brain is society trying to explain itself.