These are not content to discover individual instances of Jewish excellence in the mass around them, or to extend the renown of individual Jewish genius. They are rather concerned with the general proposition that _some_ such flux is necessary to the full action of a high and diverse culture. They tell us that but for the Jew the civilization of Europe would have grown torpid, would have settled into a fixed groove, incapable of change and of creative progress. The Jew, by this theory, is regarded as a sort of activating principle, who, whether as an irritant at the worst, or an inspiration at the best, keeps all our European life agog, and is necessary to its continuous business. These also incline to see the Jew at the origin of every great movement in European thought. They see him indirectly producing the vast transformation of the Roman Empire from a pagan, not indeed to a Jew but to a Christian, that is (in their eyes) to an Oriental mood. They see the Jew at the root of the great revolutionary philosophy which springs from the eleventh century and reaches its culmination in the great scholastics of the thirteenth. They insist upon the name of Averroës (Ibn Roshd), the philosopher of the twelfth century, the Kadi of Cordova: the exponent of Aristotle, the expositor--whom the Jews preserved: upon the great Moses ben Maimon, our Maimonides. These also put Nicolas de Lyra at the root of the Reformation: "_Si Lyra non lyrasset Luther non saltasset._" But I may remind them that the Jewish character of this man is at least doubtful, that he was of the religious Orders of Christendom. These also will certainly and with some reason ascribe to Jewish influence the great economic revolution of the seventeenth century, which has been followed by so vast an extension of wealth and of population, though hardly of human happiness. Now for all this there is certainly something to be said as an aspect of historical truth. How far it may be extended to cover, as its exponents would make it cover, the whole historical field, may be debated, but I would ask my readers to consider what change we should have seen in the development of Europe if by some magical instrument Jewish influence had been upon some one date removed. It is a theory fascinating, in a way applicable, and arresting. It is, at any rate, not nonsense.