Does the Holocaust defy rational comprehension? Kren and Rappoport--who teach history and psychology, respectively, at Kansas State--take the view that the Holocaust can and must be understood; and to that end they analyze the historical background of anti-Semitism in central and western Europe, the policies and actions of National Socialism, the record of resistance and collaboration in the ""Final Solution,"" the psychological experience of the concentration camps, and other factors. The result is a responsible survey, if not a rigorous analysis. The Holocaust, the authors point out, is one of those events which constitutes a ""crisis"" insofar as it completely disrupts conventional understandings of the world. After dismissing mystical, or purely psychological or historical explanations, they settle on the pervasive dehumanization that marked all aspects of the phenomenon, from the cold rationality of the death squads to the topsyturvy world of the camps. This leads them to the conclusion that the Holocaust shows us, above all, the potential danger of modern science and technology in a world without coherent moral values. The emphasis on rationality, management, and efficiency in assessing the Holocaust was forcefully utilized by Hannah Arendt in Eichmann in Jerusalem, which remains the most creative embodiment of this view. Essentially, Kren and Rappoport have added some psychological material to her non-psychological treatment, and removed her emphasis on genocide as a specifically modern phenomenon. A good and thorough treatment, but still an appendix to Arendt.