Religions that teach brotherly love have been used as an excuse for persecution, and our profoundest scientific insight is made into a means of mass destruction.

It would now be technically possible to unify the world, abolish war and poverty altogether, if men desired their own happiness more than the misery of their enemies.

Do not feel certain of anything.

The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as poetry.

What will be the good of the conquest of leisure and health, if no one remembers how to use them?

In considering irregular appearances, there are certain very natural mistakes which must be avoided.

We know too much and feel too little. At least, we feel too little of those creative emotions from which a good life springs.