The historian's task is to narrate, but he must also win credibility for that narrative: his task is therefore also to persuade his audience that he is the proper person to tell the story and, moreover, that his account is one that should be believed. In his capacity as persuader, the historian will often try to shape the audience's perception of his character and to use this as an additional claim to authority; indeed, among the Roman historians, where explicit professions of research are rarer than with the Greeks, the shaping of the narrator's character takes on a correspondingly larger role. But most of the historians, Greek and Roman, try to shape their audience's perception of their character. Nor is this surprising when we consider the teachings of rhetoric.