The significance of a fact is relative to [the general body of scientific] knowledge. To say that a fact is significant in science, is to say that it helps to establish or refute some general law; for science, though it starts from observation of the particular, is not concerned essentially with the particular, but with the general. A fact, in science, is not a mere fact, but an instance. In this the scientist differs from the artist, who, if he deigns to notice facts at all, is likely to notice them in all their particularity.

Whether science-and indeed civilization in general-can long survive depends upon psychology, that is to say, it depends upon what human beings desire.

Never try to discourage thinking, for you are sure to succeed.

War can only be abolished by the establishment of a world government.

I used, when I was younger, to take my holidays walking. I would cover 25 miles a day, and when the evening came I had no need of anything to keep me from boredom, since the delight of sitting amply sufficed.

The immense majority of intellectually eminent men disbelieve in the Christian religion, but they conceal the fact in public, because they are afraid of losing their incomes.

An atheist, like a Christian, holds that we can know whether or not there is a God. The Christian holds that we can know there is a God; the atheist, that we can know there is not. The Agnostic suspends judgment, saying that there are not sufficient grounds either for affirmation or for denial. At the same time, an Agnostic may hold that the existence of God, though not impossible, is very improbable; he may even hold it so improbable that it is not worth considering in practice. In that case, he is not far removed from atheism.