The Importance of History

Exequi sententias haud institui nisi insignis per honestum aut notabili dedecore, quod praecipuum munus annalium reor ne virtutes sileantur utque pravis dictis factisque ex posteritate et infamia metus sit.

My purpose is not to relate at length every motion, but only such as were conspicuous for excellence or notorious for infamy. This I regard as history’s highest function, to let no worthy action be uncommemorated, and to hold out the reprobation of posterity as a terror to evil words and deeds.

– Tacitus, Annals III