The early modern specialization of “attack theology” aimed at publicizing and refuting doctrinal deviations in works by adversaries, who often responded with defense and counter-argument. Many Reformation-era works of this genre are distasteful today because they attribute base motives to the adversaries in question. While some giant figures wrote controversial works, a broad view of the field reveals only flashes of theological brilliance. Mediocre theology predominates, but the works had the effect of hardening both Protestant-Catholic opposition and intra-Protestant differences, which today’s ecumenical commissions are laboring to reduce in their intensity and even show, in some cases, to be reconcilable differences.