The immense increase in available sources, archaeological and literary, has remade historical criticism. Ranke's application of the principles of "higher criticism" to works written since the invention of printing (_Kritik neuerer Geschichtsschreiber_) was an epoch-making challenge of narrative sources. Now they are everywhere checked by contemporary evidence, and a clearer sense of what constitutes a primary source has discredited much of what had been currently accepted as true. This is true not only of ancient history, where last year's book may be a thousand years out of date, but of the whole field. Hardly an "old master" remains an authoritative book of reference. Gibbon, Grote, Giesebrecht, Guizot stand to-day by reason of other virtues than their truth. Old landmarks drop out of sight--e.g. the fall of the Western Empire in 476, the coming of the Greeks to Italy in 1450, dates which once enclosed the middle ages. The perspective changes--the Renaissance grows less and the middle ages more; the Protestant Revolution becomes a complex of economics and politics and religion; the French Revolution a vast social reform in which the Terror was an incident, &c., &c. The result has been a complete transformation of history since the middle of the 19th century. In the 17th century the Augustinian scheme of world history received its last classic statement in Bossuet's _Histoire universelle_. Voltaire's reply to it in the 18th (_Essai sur les moeurs_) attacked its limitations on the basis of deism, and its miraculous procedure on that of science. But while there are foreshadowings of the evolutionary theory in this work, neither the _philosophe_ historians nor Hume nor Gibbon arrived at a constructive principle in history which could take the place of the Providence they rejected. Religion, though false, might be a real historic force. History became the tragic spectacle of a game of dupes--the real movers being priests, kings or warriors. The pawns slowly acquired reason, and then would be able to regulate the moves themselves. But all this failed to give a satisfactory explanation of the laws which determine the direction of this evolution. Giovanni Battista Vico (1668-1744) was the first to ask why there is no science of human history. But his lonely life and unrecognized labours leave him apart from the main movement, until his works were discovered again in the 19th century. It was A. L. H. Heeren who, at the opening of the 19th century, first laid that emphasis upon the economic factors in history which is to-day slowly replacing the Augustinian explanation of its evolution. Heeren's own influence, however, was slight. The first half of the century (apart from the scientific activity of Pertz, Guizot, &c.) was largely dominated by the romanticists, with their exaggeration of the individual. Carlyle's "great man theory of history" is logically connected with the age of Scott. It was a philosophy of history which