At moments above all when history is in the making, in these times when great and as yet incomplete pages are being traced, pages by the side of which all that had already been written will pale, it is a good and salutary thing to turn to the past in search of instruction, warning and encouragement. In this respect, the unwearying and implacable war which Athens kept up against Sparta for twenty-seven years, with the hegemony of Greece for a stake, presents more than one analogy with that which we ourselves are waging and teaches lessons that should make us reflect. The counsels which it gives us are all the more precious, all the more striking or profound inasmuch as the war is narrated to us by a man who remains, with Tacitus, despite the striving of the centuries, the progress of life and all the opportunities of doing better, the greatest historian that the earth has ever known. Thucydides is in fact the supreme historian, at the same time swift and detailed, scrupulously sifting his evidence but giving free play to intuition, setting forth none but incontestable facts, yet divining the most secret intentions and embracing at a glance all the present and future political consequences of the events which he relates. He is withal one of the most perfect writers, one of the most admirable artists in the literature of mankind; and from this point of view, in an entirely different and almost antagonistic world, he has not an equal save Tacitus. But Tacitus is before everything a wonderful tragic poet, a painter of foul abysses, of fire and blood, who can lay bare the souls of monsters and their crimes, whereas Thucydides is above all a great political moralist, a statesman endowed with extraordinary perspicacity, a painter of the open air and of a free state, who portrays the minds of those sane, ingenious, subtle, generous and marvellously intelligent men who peopled ancient Greece. The one piles on the gloom with a lavish hand, gathers dark shadows which he pierces at each sentence with lightning flashes, but remains sombre and oppressed on the very summits, whereas the other condenses nothing but light, groups together judgments that are so many radiant sheaves and remains luminous and breathes freely in the very depths. The first is passionate, violent, fierce, indignant, bitter, sincerely but pitilessly unjust and all made up of magnificent animosities; the second is always even, always at the same high level, which is that which the noblest endeavour of human reason can attain. He has no passion but a passion for the public weal, for justice, glory and intelligence. It is as though all his work were spread out in the blue sky; and even his famous picture of the plague of Athens seems covered with sunshine. 2