There is no excuse for deceiving children. And when, as must happen in conventional families, they find that their parents have lied, they lose confidence in them and feel justified in lying to them.

Science, by itself, cannot supply us with an ethic. It can show us how to achieve a given end, and it may show us that some ends cannot be achieved. But among ends that can be achieved our choice must be decided by other than purely scientific considerations. If a man were to say, "I hate the human race, and I think it would be a good thing if it were exterminated," we could say, "Well, my dear sir, let us begin the process with you." But this is hardly argument, and no amount of science could prove such a man mistaken.

Contempt for happiness is usually contempt for other people's happiness, and is an elegant disguise for hatred of the human race.

Against my will, in the course of my travels, the belief that everything worth knowing was known at Cambridge gradually wore off. In this respect my travels were very useful to me.

When one admits that nothing is certain one must, I think, also admit that some things are much more nearly certain than others.

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. So long as men are not trained to withhold judgment in the absence of evidence, they will be led astray by cocksure prophets, and it is likely that their leaders will be either ignorant fanatics or dishonest charlatans. To endure uncertainty is difficult, but so are most of the other virtues.

Moral progress has consisted in the main of protest against cruel customs, and of attempts to enlarge human sympathy.