All the arts and sciences that have to do with the management of men in the mass are founded upon a proficient practice of that sort of reckoning. The practical politician, as every connoisseur of ochlocracy knows, is not a man who seeks to inoculate the innumerable caravan of voters with new ideas; he is a man who seeks to search out and prick into energy the basic ideas that are already in them, and to turn the resultant effervescence of emotion to his own uses. And so with the religious teacher, the social and economic reformer, and every other variety of popular educator, down to and including the humblest press-agent of a fifth assistant Secretary of State, moving-picture actor, or Y.M.C.A. boob-squeezing committee. Such adept professors of conviction and enthusiasm, in the true sense, never actually teach anything new; all they do is to give new forms to beliefs already in being, to arrange the bits of glass, onyx, horn, ivory, porphyry and corundum in the mental kaleidoscope of the populace into novel permutations. To change the figure, they may give the medulla oblongata, the cerebral organ of the great masses of simple men, a powerful diuretic or emetic, but they seldom, if ever, add anything to its primary supply of fats, proteids and carbohydrates. One speaks of the great masses of simple men, and it is of them, of course, that the ensuing treatise chiefly has to say. The higher and more delicately organized tribes and sects of men are susceptible to no such ready anatomizing, for the body of beliefs upon which their ratiocination grounds itself is not fixed but changing, and not artless and crystal-clear but excessively complex and obscure. It is, indeed, the chief mark of a man emerged from the general that he has lost most of his original certainties, and is full of a scepticism which plays like a spray of acid upon all the ideas that come within his purview, including especially his own. One does not become surer as one advances in knowledge, but less sure. No article of faith is proof against the disintegrating effects of increasing information; one might almost describe the acquirement of knowledge as a process of disillusion. But among the humbler ranks of men who make up the great bulk of every civilized people the increase of information is so slow and so arduous that this effect is scarcely to be discerned. If, in the course of long years, they gradually lose their old faiths, it is only to fill the gaps with new faiths that restate the old ones in new terms. Nothing, in fact, could be more commonplace than the observation that the crazes which periodically ravage the proletariat today are, in the main, no more than distorted echoes of delusions cherished centuries ago. The fundamental religious ideas of the lower orders of Christendom have not changed materially in two thousand years, and they were old when they were first borrowed from the heathen of northern Africa and Asia Minor.