Without my attempts in natural science, I should never have learned to know mankind such as it is. In nothing else can we so closely approach pure contemplation and thought, so closely observe the errors of the senses and of the understanding, the weak and strong points of character.

Few are open to conviction, but the majority of men are open to persuasion

Men in a state of nature, uncivilized nations, children, have a great fondness for colors in their utmost brightness, and especially for yellow-red.

Happy contractedness of youth, nay, of mankind in general, that they think neither of the high nor the deep, of the true nor the false, but only of what is suited to their own conceptions.

Who longs in solitude to live, Ah! soon his wish will gain: Men hope and love, men get and give, and leave him to his pain.

It is a mistake for a taciturn, serious-minded woman to marry a jovial man, but not for a serious-minded man to marry a lighthearted woman.

Distrust those in whom the desire to punish is strong.