It is a pleasant surprise to him (the pure mathematician) and an added problem if he finds that the arts can use his calculations, or that the senses can verify them, much as if a composer found that sailors could heave better when singing his songs.

Men become superstitious, not because they have too much imagination, but because they are not aware that they have any.

Science is nothing but developed perception, interpreted intent, common sense rounded out and minutely articulated.

We do right enough darling, if we go wrong together.

Nothing is so irrevocable as mind.

The loftiest edifices need the deepest foundations.

Happiness is impossible, and even inconceivable, to a mind without scope and without pause, a mind driven by craving, pleasure, or fear. To be happy, you must be reasonable, or you must be tamed. You must have taken the measure of your powers, tasted the fruits of your passion, and learned your place in the world and what things in it can really serve you. To be happy, you must be wise.