Error is to truth as sleep is to waking. I have observed that one turns, as if refreshed, from error back to truth.

The greatest thing in this world is not so much where we stand as in what direction we are moving.

Willing is not enough, we must do.

Many people take no care of their money till they come nearly to the end of it, and others do just the same with their time.

The world cannot do without great men, but great men are very troublesome to the world.

In politics as on a sickbed men toss from side to side in hope of lying more comfortably.

Insofar as he makes use of his healthy senses, man himself is the best and most exact scientific instrument possible. The greatest misfortune of modern physics is that its experiments have been set apart from man, as it were, physics refuses to recognize nature in anything not shown by artificial instruments, and even uses this as a measure of its accomplishments.