"Be careful when you fight the monsters, lest you become one."

"Convictions are prisons."

"He who despises himself esteems himself as a self-despiser."

"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you."

"One must still have chaos in oneself to give birth to a dancing star."

"Man is more ape than many of the apes."

"Mathematics has given economics rigor, but alas, also mortis."

"Many an opportunity is lost because a man is out looking for four-leaf clovers."

"More than an end to war, we want an end to the beginnings of all wars."

"Learn from the mistakes of others. You can鈥檛 live long enough to make them all yourself."

"My great mistake, the fault for which I can't forgive myself, is that one day I ceased my obstinate pursuit of my own individuality."

"If God had wanted us to think just with our wombs, why did He give us a brain?"