Knowledge keeps no better than fish.

It is the business of future to be dangerous.... The major advances in civilization are processes that all but wreck the societies in which they occur.

Civilization advances by extending the number of important operations which we can perform without thinking of them.

It takes an extraordinary intelligence to contemplate the obvious.

If a dog jumps into your lap, it is because he is fond of you; but if a cat does the same thing, it is because your lap is warmer.

The vigour of civilised societies is preserved by the widespread sense that high aims are worth while. Vigorous societies harbour a certain extravagance of objectives, so that men wander beyond the safe provision of personal gratifications. All strong interests easily become impersonal, the love of a good job well done. There is a sense of harmony about such an accomplishment, the Peace brought by something worth while. Such personal gratification arises from aim beyond personality.

The point about zero is that we do not need to use it in the operations of daily life. No one goes out to buy zero fish. It is in a way the most civilised of all the cardinals, and its use is only forced on us by the needs of cultivated modes of thought.