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.