The Cambridge History of English and American Literature in 18 Volumes (1907–21).
Volume X. The Age of Johnson.
§ 13. Estimate of The Decline and Fall: greatness of the Theme and adequacy of the treatment
Gibbon declared, as has been seen, that he “never presumed to accept a place in the British triumvirate of historians”; but succeeding generations have concurred in assigning to The Decline and Fall the primacy, which it still holds, among historical works in our literature, and in esteeming its author the most brilliant example known of “the union of the historian and the man of letters.” From the ancients, he had taken over the rhetorical side of the historian’s task; from the French, he had derived the treatment of historical materials by a scientific method of criticism and selection; from the French, too, with the assistance of Hume and Robertson, he had learnt how to combine scientific method with artistic effect. His literary art may suffer from mannerisms, which were those of his age, as well as from foibles, which were his own, and, as a scientific history, his work has, in many respects, become superannuated; but its main and distinctive qualities continue unimpaired. Is it possible to indicate, in a few words, of which, among these qualities, the importance seems paramount?
In the first place, his choice of subject—as it gradually developed itself in the progress of the work—was supremely felicitous; for it is the greatest theme furnished by profane history. Even before Gibbon could feel assured that the complete treatment of the whole subject would be compassed by himself, he already contemplated it in its unity. What the Roman empire was, after it had attained to its full strength and maturity, and how its western division verged gradually to its decline and downfall, is only half the story; the other and much longer half shows how its fall was followed by long centuries of life in the eastern, and a revival, in new conditions, of its existence in the western, world. And more than this: Janus-like, the historian is constrained to turn, with one face, to the Roman commonwealth out of which the empire grew and of which it never lost the impress; while, with his other face, he looks forward to modern times. He bids us consider, not only what it was that declined and fell, but, also, what grew into life. The new elements of movement, the rise of new national, and that of new religious, powers must all be reviewed in their twofold relation to what they superseded and to what they prepared. The migration and settlements of the Teutonic tribes, and the spread and establishment of the Christian, and, after it, of the Mohammedan, religion, must be treated not only as helping to break up the Roman empire, but, also, as co-operating in the new order of things. The principle of the continuity of history, Freeman’s favourite theme, is, as the latest editor of Gibbon reminds us,