`Inhumanity' might have been a more suitable title, since a large part of the book is yet another testament that homo est homini lupus. The unspeakable Nazi scourge, the Gulag, Hiroshima, the cruelties carried out by Mao's Red Guard (made up for the most part of bloodthirsty, brainless teenagers), the systematic massacres carried out by Pol Pot, and the more recent ones in Africa and Bosnia, collectively have made 20th-century history a Chamber of Horrors. However, Jonathan Glover is interested less in an indictment of modern man than in pinpointing the psychological areas in human nature which dispose people to kill or torture their fellow-creatures not only with total callousness, but often with a self-righteous joy. For the most part he uncovers few monsters, but merely bears out the "banality of evil" which has been pointed out by other modern commentators. The concluding chapters are a sober, objective (though rather uninspired) consideration of how man can guard himself against his own killer instincts.