Scholarship of the past forty years on the fourth-century Trinitarian controversies has been suspicious of narratives that speak of a well-defined, monolithic, and unchanging theological parties, whether Arians or Nicenes. Against such a narrative, such scholarship has emphasized the development of multiple interrelated positions within theological alliances which exhibit significant diversity among themselves while at the same time being unified in certain fundamental tenets. Each of these traditions of Trinitarian theology emerged in different historical, theological, and polemical contexts in response to the wide variety of different impulses that shaped it. This is especially true for those theologians called "pro-Nicenes" in recent scholarship. This volume provides scholars and students with resources for studying variety among Nicene theologians in the second half of the fourth century. It presents dual-language editions of three lesser-known but seminal Nicene theological texts that are not currently available in English: Phoebadius of Agen's Against the Arians, Apollinarius of Laodicea's The Detailed Confession of the Faith, and Theodore of Mopsuestia's Debate with the Macedonians. Each text has an extensive introduction that situates the text historically and theologically. These three texts, which are different in genre, in language of original composition or preservation, and in theological focus, help us understand the complex diversity of Nicene theology in the fourth century in greater depth.