"Moral purpose...is never absent from Tacitus' mind. The sequence of events on which he chooses to focus his attention provoked the sternest moral reflections. To him, as to many others, decline and disaster seemed due to vice. Virtue and vice are continually emphasized and contrasted. As Tacitus himself says, "I regard it as the foremost task of the historian to ensure that virtues are not left unrecorded, and that evil words and deeds are made subject to the fears inspired by posterity's denunciation.""