Even in the most purely logical realms, it is insight that first arrives at what is new.

Through the greatness of the universe, which philosophy contemplates, the mind also is rendered great, and becomes capable of that union with the universe which constitutes its highest good.

There lies before us, if we choose, continual progress in happiness, knowledge and wisdom. Shall we instead choose death, because we cannot forget our quarrels? I appeal as a human being to human beings; remember your humanity, and forget the rest.

What science cannot discover, mankind cannot know.

Adventurous men enjoy shipwrecks, mutinies, earthquakes, conflagrations, and all kinds of unpleasant experiences. They say to themselves, for example, 'So this is what an earthquake is like,' and it gives them pleasure to have their knowledge of the world increased by this new item.

It has been said that man is a rational animal. All my life I have been searching for evidence which could support this.

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.