Magistra vitae

Historia est Magistra Vitae (or often written like this, which is in a more Latin spirit - Historia magistra vitae est) is a Latin expression, taken from Cicero's De Oratore, which suggests that "history is life's teacher". The phrase conveys the idea that the study of the past should serve as a lesson to the future, and was an important pillar of classical, medieval and Renaissance historiography.

The complete phrase, with English translation, is:

Historia vero testis temporum, lux veritatis, vita memoriae, magistra vitae, nuntia vetustatis, qua voce alia nisi oratoris immortalitati commendatur?

By what other voice, too, than that of the orator, is history, the evidence of time, the light of truth, the life of memory, the directress of life, the herald of antiquity, committed to immortality?

Cicero, De Oratore, II, 36.