Lewis Ayres's Nicaea and its Legacy has created a stir among historians of Christian doctrine since its publication. Its relation to the previously existing body of scholarship on fourth-century trinitarian theology is one of both consolidation and provocation. Ayres accomplishes a prodigious work of consolidation by synthesizing much of the groundbreaking scholarship that has lately transpired in the study of fourth-century trinitarian debates, while simultaneously making his own contributions toward retelling the narrative of these debates. Following Hanson, Simonetti, Barnes, and others, Ayres rejects a simplistic division between more or less uniform camps of Nicene and “Arian” theologies. Somewhat paradoxically, however, his distinctive contribution to this retelling is to insist on a fundamental unity between pro-Nicene camps in both the Greek and Latin traditions. While Ayres makes this point with forceful persuasion, the point itself is not controversial among patristic scholars. The assertion of a substantive rift between Eastern and Western trinitarian theologies has not held much sway within this milieu; it is not found in either Hanson or Simonetti, for instance, and its genealogy, traced back to the figure of de Régnon, has been famously exposed by Michel Barnes. What is provocative, however, is Ayres's insistence that there existed a geographically consistent “pro-Nicene” culture in both East and West that was also internally consistent as a superior construal of the “plain sense” of canonical Scripture. More provocative still is Ayres's polemical engagement, in the concluding chapter of his work, with modern systematic theology. Here, Ayres offers a sweeping dismissal of modern trinitarian theology as wallowing in a Hegelian wasteland, in bondage to methodological commitments that are antithetical to “pro-Nicene culture,” with no hope of a redeeming synthesis in sight. The only way forward is first to return to an integration of historical and systematic theology, based on a reappropriation of the basic tenets of pro-Nicene culture.