It is a far worthier thing to read by the light of experience than to adorn oneself with the labors of others.

It vexes me greatly that having to earn my living has forced me to interrupt the work and to attend to small matters.

Though I may not . . . be able to quote other authors, I shall rely on that which is much greater and more worthy - on experience.

Let proportion be found not only in numbers and measures, but also in sounds, weights, times, and positions, and what ever force there is.

I have been impressed with the urgency of doing. Knowing is not enough; we must apply. Being willing is not enough; we must do.

A deaf and dumb person who sees two men in conversation - may nevertheless understand from the attitudes and gestures of the speakers, how well their discussion is getting along.

You should prefer a good scientist without literary abilities than a literate one without scientific skills