James Reason has produced a major theoretical integration of several previously isolated literatures in his new book Human Error. Much of the theoretical structure is new and original. Particularly important is the identification of cognitive processes common to a wide variety of error types. Modern technology has now reached a point where improved safety can only be achieved on the basis of a better understanding of human error mechanisms. In its treatment of major accidents, the book spans the disciplinary gulf between psychological theory and those concerned with maintaining the reliability of hazardous technologies. As such, it is essential reading not only for cognitive scientists and human factors specialists, but also for reliability engineers and risk managers. No existing book speaks with so much clarity to both the theorists and the practitioners of human reliability.