Life and hope for the world are to be found only in the deeds of love.

Mathematics is, I believe, the chief source of the belief in eternal and exact truth, as well as a sensible intelligible world.

The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.

Belief in a Divine mission is one of the many forms of certainty that have afflicted the human race.

Love is wise; hatred is foolish. In this world, which is getting more and more closely interconnected, we have to learn to tolerate each other, we have to learn to put up with the fact that some people say things that we don't like. We can only live together in that way. But if we are to live together, and not die together, we must learn a kind of charity and a kind of tolerance, which is absolutely vital to the continuation of human life on this planet.

These illustrations suggest four general maxims[...]. The first is: remember that your motives are not always as altruistic as they seem to yourself. The second is: don't over-estimate your own merits. The third is: don't expect others to take as much interest in you as you do yourself. And the fourth is: don't imagine that most people give enough thought to you to have any special desire to persecute you.

They must often change, who would be constant in happiness or wisdom. Those who continually search for happiness will never find it. Happiness is made, not found. To be without some of the things you want is an indispensable part of happiness.