But, though this might satisfy Julian and those who followed him in his apostasy, it could not come to be an inner danger to the Church. With many, however, it assumed a form which at once engendered the worst errors of Gnosticism; and Gnosticism was, at first, considered a Christian heresy; so that a man might be a pantheist, of the worst kind, and still call himself Christian. St. John had foreseen the danger from the beginning, and it is said that he wrote his gospel against it because the doctrine openly denied the divinity of Christ. But the sect became much more powerful after his death, and allured many Christians who were disposed, from a misinterpretation of some texts of St. Paul on the struggle between the flesh and the spirit, to embrace a system which professed to explain the origin of that struggle.
The Alexandrian Gnosticism failed to excite in the minds of the holy monks of the East that aversion which we now feel for its tenets, inasmuch as it did not openly anathematize the Scriptures of the Old Law, nay, even preserved a certain outward respect for them, on account of the multitude of Jews living in Alexandria, and particularly because the open system of Dualism, which afterward came from Syria and in the hands of Manes established the existence of two equal and eternal principles of good and evil, found no place in the teachings of Valentinus and his school.
But even this frightful Syrian Gnosticism, which gave to the principle of evil an origin as ancient and sacred as that of God himself—Manicheism barefaced and radically immoral—so repugnant to our feelings, so monstrous to our more correct ideas, bore a semblance of truth for many minds, at that time inclined toward every thing which came from the East. We know what a firm hold those doctrines took on the great soul of Augustine, who for a long time professed and cherished them. Rome, under the pagan emperors, had received with open arms the Oriental gods and the philosophy which endeavored to explain their mythology; and many gifted minds of the third and fourth centuries lost themselves in the contemplation of those mysteries which from out Central Asia spread a lurid glare over the Western world.
This first danger, however, was warded off by the writings of St. Ignatius of Antioch, St. Irenaeus of Lyons, Clement of Alexandria, Tertullian, Origen, St. Epiphanius, Theodoret, and others, long before the time of St. Augustine, the last of them. Gnosticism was prevented from any longer imparting a wrong tendency to Christian doctrines, and it died out, until restored during the Crusades to revive in the middle ages in its most malignant form.
But at the very moment of its decline, philosophy entered the Church; almost to wreck her by inspiring Arius and Pelagius. The teachings of the first were clearly Neo-Platonic; of the second, Stoic: and all the errors prevalent in the Church from the third to the sixth century originated in Arianism and Pelagianism.
In Plato, as read in Alexandria, Arius found all the material for his doctrine, which spread like wild-fire over the whole Church. Many things conspired to swell the number of his adherents: the ardent love for philosophy so inherent in the Eastern Church, to the extent of many believing that Plato was almost a Christian, and his doctrines therefore endowed with real authority; the natural disposition of men to adopt the new and a seeming rational explanation of unfathomable mysteries; the apparent agreement of his doctrine with certain passages of Scripture, where the Son is said to be inferior to the Father; but chiefly the satisfaction it afforded to a number of new Christians who had embraced the faith at the conversion of Constantine on political rather than conscientious grounds, and who were at once relieved of the supernatural burden of believing in a God-man, born of a woman, and dying on a cross. Faith reduced to an opinion; religion become a philosophy; a mere man, let his endowments be what they might, recognized as our guide, and not overwhelming us with the dread weight of a divine nature; all this explains the historic phrase of St. Jerome after the Council of Rimini, "The world groaned and wondered to find itself Arian."
Any person acquainted with ecclesiastical history knows how the Church of Christ would have surely become converted into a mere rational school, under the pressure of these doctrines, were it not for the promises of perpetuity which she had received.
We know also what a time it took to establish truth: how many councils had to meet, how many books had to be written, the efforts required from the rulers of the Church, chiefly from the Roman pontiffs, to calm so many storms, to explain so many difficult points of doctrine, to secure the final victory.
And, after all had been accomplished, there still remained the root of the evil engrafted in what we call the philosophical turn of mind of the Western nations—that is to say, in the disposition to call every thing in question, to seek out strange and novel difficulties, to start war-provoking theories in the midst of peace, to aim at founding a new school, or at least to stand forth as the brilliant and startling expounder of old doctrines in a new form, in fine to add a last name to the list, already over-long, of those who have disturbed the world by their skill in dialectics and sophism.
Pelagius followed Arius, and his errors had the same object in view in the long-run, to strip our holy religion of all that is spiritual and divine.