§ 4. "Set speeches," says Voltaire, "are a sort of oratorical lie, which the historian used to allow himself in old times. He used to make his heroes say what they might have said....At the present day these fictions are no longer tolerated. If one put into the mouth of a prince a speech which he had never made, the historian would be regarded as a rhetorician." How did it happen that Thucydides allowed himself this "oratorical lie,"—Thucydides, whose strongest characteristic is devotion to the truth, impatience of every inroad which fiction makes into the province of history, laborious persistence in the task of separating fact from fable; Thucydides, who was not constrained, like later writers of the old world, by an established literary tradition; who had no Greek predecessors in the field of history, except those chroniclers whom he despised precisely because they sacrificed truth to effect? Thucydides might rather have been expected to express himself on this wise: "The chroniclers have sometimes pleased their hearers by reporting the very words spoken. But, as I could not give the words, I have been content to give the substance, when I could learn it."