Few modern novels have stirred up so much partisanship and violent controversy as Arthur Koestler's Darkness at Noon. Its champions have proclaimed it as a penetrating study of revolutionary psychology and the compulsions which lead to the catharsis of confession; its adversaries, first to admit its overwhelming power, attack it on the ground of its political implications.  Both agree that Arthur Koestler is a novelist of the foremost rank and a man with the courage of his strong and brilliant convictions. Recent history has provided corroborating testimony to his fictional critique of the ruthlessness of modern revolutionary procedures.