This comprehensive, objective and highly detailed book is part of a study by the Fund for the Republic on Communism in American Life. As the author makes clear the book is not to be construed as simply an examination of Communism in the churches or as an expose of ecclesiastical intrigue. Though he deals with special instances of clerical affiliation with Communist organizations he presents a broad and general picture of Church attitudes toward a number of crises -- from the Bolshevik Revolution to the Air Force assertion in 1960 that Communists and fellow-travelers had infilitrated into the churches. He says that though the Communist Party in America never did undertake a full-scale campaign of subversion they did seek, sporadically, to infiltrate Church groups through the device of the front organization -- mainly after the twenties in the effort to achieve a United Front- and that they were most successful when the interests of the U.S. and Russia were interwined, during World War II. Though he deals with Communist activity in all church affiliations (Catholics, especially, were reached through labor unions) most of the emphasis is on the Protestant clergy ""because of their greater freedom to involve themselves in social and political activities"". He concludes that the number of clergymen who have been Communists or persistent fellow travelers has been minute and he estimates that out of 500,000 ordained clergymen since 1930 perhaps only 25 of these remain within the Communist apparatus, and most of them are not serving pulpits. He insists that the real danger involving Communism has always been the mistaking of genuine passionate concern for social justice with conspiratorial activities and that the far more serious and pressing problem is one of ""apathy and complacency and a disquieting lack of social zeal"". Profusely documented this is a book for the scholar and student, not for those seeking titillating revelations of treason in high places.