Hillerbrand's crowded, panoramic survey of the Protestant Reformation manages to convey both the complexity and confusion of the ""monk's squabble"" which tore asunder Christendom. Hillerbrand repeatedly stresses the inadequacy of any monistic interpretation. Beginning as a call for a deepened spirituality, a reaction against ossified ritual, a return to the scriptural sources of faith, and an attack on ecclesiastical abuses (""Reform was simplification""), the Reformation rapidly became politicized. In its temporal guise the movement became a power struggle between the Roman Curia and the princes of Europe -- eventually a ""comprehensive repudiation of ecclesiastical control over government."" Within Luther's Germany its course and outcome were determined by the internecine conflicts between imperial authority and territorial particularism. Greed -- the desire for pecuniary gain at the expense of the Church -- played as great a role as piety; the Elector of Saxony who harbored Luther from the wrath of Rome was as key a figure as Jan van Leyden, the Anabaptist leader. In order to establish the multiplicity of events and the sectarian splits among the reformers themselves, Prof. Hillerbrand (CUNY) leapfrogs the map of Europe from Germany to Switzerland to Scotland; from Luther to Zwingli to John Knox. Inevitably those unfamiliar with the period win have some difficulty untangling the complex threads even though the author does his best to explicate the underlying doctrines of the rebels. Occasionally Hillerbrand himself seems to equivocate: on the one hand he attributes the early success of Lutheranism to its willingness to take theological controversy ""to the marketplace, the tavern and the street""; on the other he suggests that the common people who were largely illiterate were frequently ""only little concerned with things spiritual."" But Hillerbrand succeeds well in demonstrating that ""neither historically nor theologically was there ever a single Reformation.