We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.

Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe.

I do not need drugs to be a genius, do not take a genius to be human, but I need your smile to be happy.

Towering genius disdains a beaten path. It seeks regions hitherto unexplored.

Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.

After making a mistake or suffering a misfortune, the man of genius always gets back on his feet.