The fulness of truth had thus appeared corporally in the Word become flesh, and by this appearance a new epoch had begun to man,[171] and henceforth there were only two attitudes of the human spirit possible towards the truth thus revealed. On the one hand, it might recognise the revelation as truth given by God, and make it the standard and guiding principle of speculation. On the other hand, it might use its freedom to assume an independent standing-point over against this revelation, which it might subject to its private reason. In the former case revelation would be primary and reason secondary; in the latter case the position would be reversed. Reason would take what it liked and reject what it disliked in revelation. In the former, reason, using the natural powers of the human mind in subordination to revealed truth, and accepting the Christian mysteries as data, would proceed by profound meditation upon them, would connect doctrine with doctrine, and come to the perception of the harmony contained in the structure of the revelation made in Christ; to a system, in fine, of speculative theology. In the latter, following its particular bias, according to the spirit of the time in each period, it would attempt to subject revelation to itself, to alter some parts, to discard others, to improve or reject according to its own inward attraction. The one is the principle of orthodoxy, the other that of heresy. As a matter of fact, we find from the institution of the Christian Church—that is, the entrance of Christ's Person into the world—a spiritual war commence, which runs through all the ages, and of which the time from the Day of Pentecost to the convocation of the Nicene Council is only the first period. But in that period the combatants are already well defined, the two standing-points definitely taken up, and the battle waged even upon the most important of all truth, the existence and the character of God Himself. The Christian God is carried through three centuries, and impressed upon the belief of men by the Christian Church; the philosophic god is set up against Him by those who subjected faith to reason; and in the collision between the two the pantheon of false gods is dispersed and shattered, and dissolved in the pure light of the Christian heaven. That first condition of the Christian Church, during which it lived on pure faith—I mean the simple historical transmission of its worship, its sacraments, its discipline, and its government, as they were instituted—lasted for several generations; it may be said quite to the end of the second century. During this whole time the attacks of human reason acting upon the principle of heresy were incessant, and it was to defend themselves against these attacks that those who stood entirely upon the ground of faith and tradition in the first instance gradually betook themselves to the arms of reason, reflection, and learning superadded to the faith.