This book is based on a most meticulous examination of medieval authorities and the growth of medieval theology is essentially told in their own words. What is more important, however, than the astounding number of primary sources the author has consulted or his sovereign familiarity with modern studies on his subject, is his ability to discern form and direction in the bewildering growth of medieval Christian doctrine and, by thoughtful emphasis and selection, to show the pattern of that development in a lucid and persuasive narrative.