Augustine’s word and his example sufficiently attest the fact that the Christian Faith constituted the primary intellectual interest with the Fathers. While not annihilating other activities of the mind, this dominant interest lowered their dignity by forcing them into a common subservience. Exerting its manifold energies in defining and building out the Faith, in protecting it from open attack or insidious corruption, it drew to its exigencies the whole strength of its votaries. There resulted the perfected organization of the Catholic Church and the production of a vast doctrinal literature. The latter may be characterized as constructive of dogma, theoretically interpretative of Scripture, and polemically directed against pagans, Jews, heretics or schismatics, as the case might be. It was constructive of dogma through the intellectual necessity of apprehending the Faith in concepts and modes of reasoning accepted as valid by the Graeco-Roman world. In the dogmatic treatises emanating from the Hellenic East, the concepts and modes of reasoning were those of the later phases of Greek philosophy. Prominent examples are the _De principiis_ of Origen or the _Orationes_ of Athanasius against the Arians. For the Latin West, Tertullian’s _Adversus Marcionem_ or the treatises of Hilary and Augustine upon the Trinity serve for examples. The Western writings are distinguished from their Eastern kin by the entry of the juristic element, filling them with a mass of conceptions from the Roman Law.[65] They also develop a more searching psychology. In both of these respects, Tertullian and Augustine were the great creators. Secondly, this literature, at least in theory, was interpretative or expository of Scripture. Undoubtedly Origen and Athanasius and Augustine approached the Faith with ideas formed from philosophical study and their own reflections; and their metaphysical and allegorical treatment of Scripture texts elicited a significance different from the meaning which we now should draw. Yet Christianity was an authoritatively revealed religion, and the letter of that revelation was Holy Scripture, to wit, the gradually formed canon of the Old and New Testaments. If the reasoning or conclusions which resulted in the Nicene Creed were not just what Scripture would seem to suggest, at all events they had to be and were confirmed by Scripture, interpreted, to be sure, under the stress of controversy and the influence of all that had gone into the intellectual natures of the Greek and Latin Fathers. And the patristic faculty of doctrinal exposition, that is, of reasoning constructively along the lines of Scriptural interpretation, was marvellous. Such a writing as Augustine’s Anti-Pelagian _De spiritu et littera_ is a striking example.