This is one of the most important books on religion in America to appear in recent years. Its author is a recognized authority on the problems of mental health and has been the leader in the movement for pastoral clinical training. In the present volume he turns to a study of the reaction of groups to times of crisis such as economic depression or war. His conclusion is that out of times of crisis new religious insights are sharpened by vivid emotional experiences and come into being to have a revivifying effect upon religion. These new crisis-born experiences enter into the organizational life of religion:e.g. the Methodists of a century ago and the ""holiness sects"" of today. But, in time, the original enthusiasm fades away and a religion born of crisis becomes a religion of custom. Boisen's thesis is documented by reference to detailed study of the state of Protestantism in a typical western county, by reference to his findings as to the bearing of religion upon mental health and ill-health and by a tracing of the evolution of Methodism and Quakerism. A very stimulating book which should be of interest to sociologists, psychologists and psychiatrists and which is a must for Protestant ministers who want to take a long and searching look ahead into the future of Protestantism in America.