Instead of being satisfied to alleviate suffering, we shall labor hard and continually to prevent it.

Be not dismayed; in the future lies the Promised Land.

When one door closes, another one opens, but sometimes we wait too long looking at the closed door, and never realize that another door has been opened.

Now I feel as if I should succeed in doing something in mathematics, although I cannot see why it is so very important. . . The knowledge doesn't make life any sweeter or happier, does it?

If I regarded my life from the point of view of the pessimist, I should be undone. I should seek in vain for the light that does not visit my eyes and the music that does not ring in my ears. I should beg night and day and never be satisfied. I should sit apart in awful solitude, a prey to fear and despair. But since I consider it a duty to myself and to others to be happy, I escape a misery worse than any physical deprivation.

I seldom think about my limitations, and they never make me sad. Perhaps there is just a touch of yearning at times; but it is vague, like a breeze among flowers.

It's wonderful to climb the liquid mountains of the sky. Behind me and before me is God and I have no fears.