Voltaire was always conscious, though not so clearly as writers are now, of the great historical principle that besides the prominent men of a generation there is a something at work underneath, a moving current on whose flood they are borne. He never fixed this current by any of the names which now fall so glibly from our lips,—tendency of the times, tenor of public opinion, spirit of the age, and the like, by which we give a collective name to groups of sentiments and forces, all making in what seems to be a single direction. But although unnamed, this singular and invisible concurrence of circumstance was yet a reality to him. The age was something besides its heroes, and something besides its noisiest and most resounding occurrences. His divisions of the great epochs of humanity are undoubtedly open to much criticism, because the principles on which he drew the dividing lines have lost their force in new generations. It was to be expected that they would do so; and his four great epochs[244] were not likely to remain the four great epochs of a posterity, which has partially learnt the lesson that he had not learnt at all, that perfection in the fine arts is not the highest mark of an age in which humanity may glory. Nevertheless, we are bound to recognise that a new way of regarding human action, as well as a new way of composing history, was being introduced by a writer whose first paragraph declared that he proposed to himself a greater object than an account of the life of Lewis XIV.; that he designed to paint for the instruction of posterity, not the actions of a single man, but the spirit of men; and that while all periods must be alike to one who only desires to fill his memory with facts, discrimination among them cannot be dispensed with for one who thinks.