"Nec eventus modo hoc docet, stultorum iste magister est, sed eadem ratio, quae fuit futuraque, donec res eaedem manebunt, immutabilis est."
Livy, History of Rome, Book 22
And it is not only the result that will instruct them, that teacher of fools, but reason itself, which was and will be unchanging, so long as the same fundamental conditions still hold.
"Where such a shift in power is in favor of the governing elite, Power will achieve its murderous potential. It simply waits for an excuse, an event of some sort, an assassination, a massacre in a neighboring country, an attempted coup, a famine, or a natural disaster, to justify the beginning of murder en masse. Most state sponsored murder occurs under the cover of war, revolution, or guerrilla war, or in their aftermath."
R. J. Rummel