Of all thieves, fools are the worst; they rob you of time and temper.

What makes poetry? A full heart, brimful of one noble passion.

Every decided colour does a certain violence to the eye, and forces the organ to opposition.

I have heard myself accused of being an opponent, an enemy of mathematics, which no one can value more highly than I, for it accomplishes the very thing whose achievement has been denied me.

Thinking is easy, acting is difficult, and to put one's thoughts into action is the most difficult thing in the world.

There is a politeness of the heart; this is closely allied to love.

Nature goes her own way, and all that to us seems an exception is really according to order.