It had been boldly predicted by some of the early Christians that the conversion of the world would lead to the establishment of perpetual peace. In looking back, with our present experience, we are driven to the melancholy conclusion that, instead of diminishing the number of wars, ecclesiastical influence has actually and very seriously increased it. We may look in vain for any period since Constantine, in which the clergy, as a body, exerted themselves to repress the military spirit, or to prevent or abridge a particular war, with an energy at all comparable to that which they displayed in stimulating the fanaticism of the crusaders, in producing the atrocious massacre of the Albigenses, in embittering the religious contests that followed the Reformation. Private wars were, no doubt, in some degree repressed by their influence; for the institution of the “Truce of God” was for a time of much value, and when, towards the close of the middle ages, the custom of duels arose, it was strenuously condemned by the clergy; but we can hardly place any great value on their exertions in this field, when we remember that duels were almost or altogether unknown to the Pagan world; that, having arisen in a period of great superstition, the anathemas of the Church were almost impotent to discourage them; and that in our own century they are rapidly disappearing before the simple censure of an industrial society. It is possible—though it would, I imagine, be difficult to prove it—that the mediatorial office, so often exercised by bishops, may sometimes have prevented wars; and it is certain that during the period of the religious wars, so much military spirit existed in Europe that it must necessarily have found a vent, and under no circumstances could the period have been one of perfect peace. But when all these qualifications have been fully admitted, the broad fact will remain, that, with the exception of Mohammedanism, no other religion has done so much to produce war as was done by the religious teachers of Christendom during several centuries. The military fanaticism evoked by the indulgences of the popes, by the exhortations of the pulpit, by the religious importance attached to the relics at Jerusalem, and by the prevailing hatred of misbelievers, has scarcely ever been equalled in its intensity, and it has caused the effusion of oceans of blood, and has been productive of incalculable misery to the world. Religious fanaticism was a main cause of the earlier wars, and an important ingredient in the later ones. The peace principles, that were so common before Constantine, have found scarcely any echo except from Erasmus, the Anabaptists, and the Quakers;(527) and although some very important pacific agencies have arisen out of the industrial progress of modern times, these have been, for the most part, wholly unconnected with, and have in some cases been directly opposed to, theological interests.