At the outset of the History, Thucydides indicates his general conception of his work and states the principles which governed its composition. His pains to make the History of the Peloponnesian War scrupulously accurate in its facts, as well as answering to a higher sense of literary composition, has made it an exemplar of historical journalism for over two millennia. At the very beginning of the war between Athens and Sparta, he was of the conviction that it would prove more important than any event the Greeks had yet recorded.

So far as the language of the speeches is concerned, Thucydides plainly avows that his own, adhering as closely as possible to the general sense of what was actually said, but the case of Pericles is probably an exception. The speeches of Pericles, which Thucydides personally heard, offer several examples of that bold imagery which Aristotle and Plutarch agree in ascribing to Pericles; while the Funeral Oration especially has a certain majesty of rhythm and a lofty grandeur which the historian has given to no other speaker.

Thucydides stands alone among the men of his own days and has no superior of any age in the breadth of mental grasp which could seize the general significance of particular events. The political education of mankind began in Greece, and in the time of Thucydides their political life was still young. Thucydides knew only of the small city-state on the one hand and on the other the vast barbaric kingdom; and yet, as has been well said of him: "There is hardly a problem in the science of government which the statesman will ot find, if not solved, at any rate handled, in the pages of this universal master."