[53] "Nothing but the great number of citizens in a state can occasion the flourishing of the arts and sciences. Accordingly, we see that, in all ages, it was great empires only which enjoyed this advantage. In these great states, the arts, especially that of agriculture, were soon brought to great perfection, and thus that leisure afforded to a considerable number of men, which is so necessary to study and speculation. The Babylonians, Assyrians, and Egyptians, had the advantage of being formed into regular, well-constituted states."--_Origin of Laws and Sciences, and their Progress among the most Ancient Nations._ By President DE GOGUET. Edinburgh, 1761, vol. i. pp. 272-273.--H. [54] "Conquests, by uniting many nations under one sovereign, have formed great and powerful empires, out of the ruins of many petty states. In these great empires, men began insensibly to form clearer views of politics, juster and more salutary notions of government. Experience taught them to avoid the errors which had occasioned the ruin of the nations whom they had subdued, and put them upon taking measures to prevent surprises, invasions, and the like misfortunes. With these views they fortified cities, secured such passes as might have admitted an enemy into their country, and kept a certain number of troops constantly on foot. By these precautions, several States rendered themselves formidable to their neighbors, and none durst lightly attack powers which were every way so respectable. The interior parts of such mighty monarchies were no longer exposed to ravages and devastations. War was driven far from the centre, and only infected the frontiers. The inhabitants of the country, and of the cities, began to breathe in safety. The calamities which conquests and revolutions had occasioned, disappeared; but the blessings which had grown out of them, remained. Ingenious and active spirits, encouraged by the repose which they enjoyed, devoted themselves to study. _It was in the bosom of great empires the arts were invented, and the sciences had their birth._"--_Op. cit._, vol. i. Book 5, p. 326.--H. [55] The history of every great empire proves the correctness of this remark. The conqueror never attempted to change the manners or local institutions of the peoples subdued, but contented himself with an acknowledgment of his supremacy, the payment of tribute, and the rendering of assistance in war. Those who have pursued a contrary course, may be likened to an overflowing river, which, though it leaves temporary marks of its destructive course behind, must, sooner or later, return to its bed, and, in a short time, its invasions are forgotten, and their traces obliterated.--H.