This was the doctrine of the Nominalists, as it was of Aristotle before them. It was the doctrine of the Reformers, except, if we remember rightly, of Huss. The University of Leipzig was founded upon it. It is the current doctrine of the present day, and harmonizes well with the current Materialism. Not that Nominalism in itself, and as Leibnitz held it, is necessarily materialistic, but Realism is essentially antimaterialistic. The Realists held with Plato,--but not in his name, for they, too, claimed to be Aristotelian, and preëminently so,--that the ideal must precede the actual. So far they were right. This was their strong point. Their error lay in claiming for the ideal an objective reality, an independent being. Conceptualism was only another statement of Nominalism, or, at most, a question of the relation of language to thought. It cannot be regarded as a third issue in this controversy,-- a controversy in which more time was consumed, says John of Salisbury, "than the Caesars required to make themselves masters of the world," and in which the combatants, having spent at last their whole stock of dialectic ammunition, resorted to carnal weapons, passing suddenly, by a very illogical _metabasis_, from "universals" to particulars. Both parties appealed to Aristotle. By a singular fortune, a pagan philosopher, introduced into Western Europe by Mohammedans, became the supreme authority of the Christian world. Aristotle was the Scripture of the Middle Age. Luther found this authority in his way and disposed of it in short order, devoting Aristotle without ceremony to the Devil, as "a damned mischief-making heathen." But Leibnitz, whose large discourse looked before as well as after, reinstated not only Aristotle, but Plato, and others of the Greek philosophers, in their former repute;--"Car ces anciens," he said, "étaient plus solides qu'on ne croit." He was the first to turn the tide of popular opinion in their favor.