The History of this gradual Culture of the Human Race, as History properly so called, is again made up of two intimately connected elements; one a priori, and the other a posteriori. The a priori is the World-Plan, the general features of which we have set forth in our first lecture, conducting Humanity through the Five Epochs already enumerated. Without historical information at all the Thinker may know that these Epochs, as we have described them, must succeed each other, and may also be able, in the same way, to characterize generally such of them as have not yet taken their place in History as facts. Now this development of the Human Race does not take place at once, as the philosopher pictures it to himself in thought, but, disturbed by foreign powers, it takes place gradually, at different times, in different places, and under particular circumstances. These conditions do not by any means arise from the Idea of the World-Plan, but are unknown to it; and since there is no other Idea of a World-Plan, they are an Absolute Unknown to Philosophy: and here begins the pure Empiricism of History;—its a posteriori element;—History in its own proper form.
The Philosopher who in his capacity of Philosopher meddles with History follows the a priori course of the World-Plan, which is clear to him without the aid of History at all; and the use which he makes of History is not to prove anything by it, for his principles are already proved independently of History; but only to illustrate and make good in the actual world of History, that which is already understood without its aid. Throughout the whole course of events, therefore, he selects only the instances in which Humanity really advances towards the true end of its being, and appeals only to these instances,—laying aside and rejecting everything else; and as he does not intend to prove historically that Humanity has to pursue this course, having already proved
