I must consider more closely this cycle of good and bad days which I find coursing within myself. Passion, attachment, the urge to action, inventiveness, performance, order all alternate and keep their orbit; cheerfulness, vigor, energy, flexibility and fatigue, serenity as well as desire. Nothing disturbs the cycle for I lead a simple life, but I must still find the time and order in which I rotate.

Ah! my poor brain is racked and crazed, My spirit and senses amazed!

Die Mathematiker sind eine Art Franzosen. Spricht man zu ihnen, so übersetzen sie alles in ihre eigene Sprache, und so wird es alsobald etwas ganz anderes. Mathematicians are a kind of Frenchmen. Whenever you say anything or talk to them, they translate it into their own language, and right away it is something completely different.

Voluntary dependence is the wonderful form of existence, and how could that be possible without love?

The senses do not deceive us, but the judgment does.

Be above it! Make the world serve your purpose, but do not serve it.

Several classical sayings that one likes to repeat had quite a different meaning from the ones later times attributed to them.