Controversy within the Christian Church, and particularly within the Roman Catholic Church, today centers around three subjects: faith versus free inquiry, the validity and extent of ecclesiastical authority, and the immutability (or mutability) of dogma. Dulles' book is concerned with each of these foci. Its purpose, however, is not to resolve specific controversies but to put the whole question in its proper perspective: present day conflicts in the subject areas are founded upon a concept of faith, authority, and dogma as static, coercive elements; whereas, in fact, they are, as history proves, immensely fluid and capable of ""discontinuous quantum leaps"" on those occasions when human civilization enters a new phase. Thus, Dulles analyzes the relationship between the reality of faith and its historical forms, between ecclesiastical authority and personal conviction, and between dogma and the need for change. A thoughtful, if somewhat abstract, work, dealing with concepts rather than with situations, the quality and authority of which commend the book to Catholic theologians and to a peripheral Protestant readership.