Art and act, painting and battle, artist and warrior--Peter Gay avers--are alike the sum of multiple causes, both without and within the individual. And these, he contends, can be uncovered, evaluated, and ranked. Art is the occasion merely, enabling Gay to extend the claim of Style in History (1974) for the reliability of objective historical inquiry (contra the subjectivist view of E. H. Carr, among others) and specifically to oppose Lawrence Stone's contention that any attempt to find a hierarchy of causes is ""futile and intellectually dishonest."" To aid investigation, he posits three kinds of causes--from the worlds of culture, craft, and private life--which operate to some degree in every instance, always with a subjective dimension. Thus, ""Munch's lithographs depicting erotic vampires and castrating madonnas join a craftsman's skill to a neurotic's anxieties and to a widespread late-nineteenth-century response to modern feminism."" Extended studies of Manet, Gropius, and Mondrian--whose roots differ suggestively--illustrate Gay's method and bring him to some more or less unexpected conclusions. Manet the supreme individualist is deftly characterized as ""a rebel in a top hat,"" and, with some fancy analytical footwork, shown to be a modernist who ""found his values, and the principal impulses for his work, in the urban industrial society growing around him."" Gropius, famed for his ""commitment to social principles,"" comes rather to exemplify ""a craftsman's trained response to a stimulus""--namely, the building project at hand. Mondrian, proponent of reason, is revealed as a mystic who regarded art as ""the path of ascension; away from matter""--and, most strikingly, as a man of ""obsessive rigidity"" whose art was a highly elaborate sublimation of terrifying passions. But, as Gay is careful to note, ""his paintings offer impressive evidence of just how much beauty the talented can wrest from fear,"" and not from fear alone. A skeleton key to history's shards and a vivid sample of its pleasures.