Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.

The desire to understand the world and the desire to reform it are the two great engines of progress, without which human society would stand still or retrogress.

We may often do as we please - but we cannot please as we please.

Although it is a gloomy view to suppose that life will die out, sometimes when I contemplate the things that people do with their lives I think it is almost a consolation

Happiness is not best achieved by those who seek it directly.

Affection cannot be created; it can only be liberated.

The pure mathematician, like the musician, is a free creator of his world of ordered beauty.