The means whereby to identify dead forms is Mathematical Law. The means whereby to understand living forms is Analogy. By these means we are enabled to distinguish polarity and periodicity in the world. It is, and has always been, a matter of knowledge that the expression- forms of world-history are limited in number, and that eras, epochs, situations, persons are ever repeating themselves true to type. Napoleon has hardly ever been discussed without a side-glance at Cæsar and Alexander—analogies of which, as we shall see, the first is morphologically quite inacceptable and the second is correct—while Napoleon himself conceived of his situation as akin to Charlemagne’s. The French Revolutionary Convention spoke of Carthage when it meant England, and the Jacobins styled themselves Romans. Other such comparisons, of all degrees of soundness and unsoundness, are those of Florence with Athens, Buddha with Christ, primitive Christianity with modern Socialism, the Roman financial magnate of Cæsar’s time with the Yankee. Petrarch, the first passionate archæologist (and is not archæology itself an expression of the sense that history is repetition?) related himself mentally to Cicero, and but lately Cecil Rhodes, the organizer of British South Africa, who had in his library specially prepared translations of the classical lives of the Cæsars, felt himself akin to the Emperor Hadrian. The fated Charles XII of Sweden used to carry Quintus Curtius’s life of Alexander in his pocket, and to copy that conqueror was his deliberate purpose. Frederick the Great, in his political writings—such as his _Considérations_, 1738—moves among analogies with perfect assurance. Thus he compares the French to the Macedonians under Philip and the Germans to the Greeks. “Even now,” he says, “the Thermopylæ of Germany, Alsace and Lorraine, are in the hands of Philip,” therein exactly characterizing the policy of Cardinal Fleury. We find him drawing parallels also between the policies of the Houses of Habsburg and Bourbon and the proscriptions of Antony and of Octavius. Still, all this was only fragmentary and arbitrary, and usually implied rather a momentary inclination to poetical or ingenious expressions than a really deep sense of historical forms.