"Forty years ago," wrote Matthew Arnold in 1883, "when I was an undergraduate at Oxford, voices were in the air there which haunt my memory still." One of those voices was that of John Henry Newman preaching from the pulpit of St. Mary's Church: "Who could resist the charm of that spiritual apparition, gliding in the dim afternoon light through the aisles of St. Mary's, rising into the pulpit, and then, in the most entrancing of voices, breaking the silence with words and thoughts which were a religious music--subtle, sweet, mournful"" Arnold's recollection in his essay "Emerson" is an apt tribute, for it suggests the personality and magnetism of the man while also noting the quality both of his words and of his thoughts. Eloquent in speech and writing, Newman also had something distinctive and powerful to say. He said it not for the specialists in theology or philosophy...