Passing from speculations to facts, we observe that progress has been the exception rather than the law of human history. And therefore we are not surprised to find that the idea of progress is of modern rather than of ancient date; and, like the idea of a philosophy of history, is not more than a century or two old. It seems to have arisen out of the impression left on the human mind by the growth of the Roman Empire and of the Christian Church, and to be due to the political and social improvements which they introduced into the world; and still more in our own century to the idealism of the first French Revolution and the triumph of American Independence; and in a yet greater degree to the vast material prosperity and growth of population in England and her colonies and in America. It is also to be ascribed in a measure to the greater study of the philosophy of history. The optimist temperament of some great writers has {ccxiv} assisted the creation of it, while the opposite character has led a few to regard the future of the world as dark. The 'spectator of all time and of all existence' sees more of 'the increasing purpose which through the ages ran' than formerly: but to the inhabitant of a small state of Hellas the vision was necessarily limited like the valley in which he dwelt. There was no remote past on which his eye could rest, nor any future from which the veil was partly lifted up by the analogy of history. The narrowness of view, which to ourselves appears so singular, was to him natural, if not unavoidable. * * * * * V. For the relation of the Republic to the Statesman and the Laws, and the two other works of Plato which directly treat of politics, see the Introductions to the two latter; a few general points of comparison may be touched upon in this place.