Father Kaiser's book represents an attempt, largely successful, to sketch out the broad lines of a Catholic theology of the activity called ""work."" (The term is used to signify both manual and intellectual labor.) After an initial definition of terminology, the author furnishes the necessary historical background to the question from Old Testament times through the Middle Ages up to the present, emphasizing the evolution of the modern concept of work and the latter's specific differences from the attitudes of former ages. There are particularly interesting comparative studies of the Marxist concept of work, the monastic concept, and of the attitudes of capitalism. The main value of the book, however, lies in Father Kaiser's synthesization of a vast literature of Catholic thought on the subject, drawn principally from papal documents and from the works of the great theologians through the ages. That value is more than sufficient to offset such deficiencies as an inadequate account of the influence of the Protestant work-ethic on modern Catholic thought, and the text-book pedantry of the author's presentation.