Hannah Arendt's superb study of Adolf Eichmann operates on a three-pronged front: as a legalistic clearing ground (the Israeli-or-International Court controversy; the relation to the Nuremberg and Successor trials; the forced deportations and "final solution"; Nazis, past and present, and West Germany today); as a psychological description (was Eichmann really a "perverted sadist" or was he "terribly and terrifyingly normal",- a sort of totalitarian age Everyman who no longer knows or feels what a "criminal act" is?); and as a philosophical query (what is the meaning of justice, what are the measurements of morality, when through Auschwitz and Buchenwald the very concepts of good and evil become banalities?). Miss Arendt covered the Jerusalem scene as correspondent for The New Yorker, thus much of the merely factual material here seems, journalistically speaking, old hat. But no matter; as everyone knows, Miss Arendt writes like an angel who could outwit the devil; ten or twenty years from now her little book should still be one of the key references to an understanding of barbarism-and-bureaucracy, a 20th century phenomenon.