A theory is scientific only if it can be disproved. But the moment you try to cover absolutely everything the chances are that you cover nothing..

All science is full of statements where you put your best face on your ignorance, where you say: ... we know awfully little about this, but more or l….

If you walk along the street you will encounter a number of scientific problems. Of these, about 80 per cent are insoluble, while 19½ per cent are tr….

Time is that which is manufactured by clocks..

[Science doesn't deal with facts; indeed] fact is an emotion-loaded word for which there is little place in scientific debate..

Sometimes I am a little unkind to all my many friends in education ... by saying that from the time it learns to talk every child makes a dreadful nu….

The scientist … must always be prepared to deal with the unknown. It is an essential part of science that you should be able to describe matters in a….

What I remember most clearly was that when I put down a suggestion that seemed to me cogent and reasonable, Einstein did not in the least contest thi….

The true contrast between science and religion is that science unites the world and makes it possible for people of widely differing backgrounds to w….

On the most usual assumption, the universe is homogeneous on the large scale, i.e. down to regions containing each an appreciable number of nebulae. ….

An observer situated in a nebula and moving with the nebula will observe the same properties of the universe as any other similarly situated observer….

Our humanist attitude should therefore throughout be to stress what we all have in common with each other and relegate quarrelsome religion to the pr….

[Newton's calculations] entered the marrow of what we know without knowing how we know it..

The kind of lecture which I have been so kindly invited to give, and which now appears in book form, gives one a rare opportunity to allow the bees i….

The test of science is not whether you are reasonable—there would not be much of physics if that was the case—the test is whether it works. And the g….

We find no sense in talking about something unless we specify how we measure it; a definition by the method of measuring a quantity is the one sure w….

The landscape has been so totally changed, the ways of thinking have been so deeply affected, that it is very hard to get hold of what it was like be….

... an opportunity to allow the bees in one's bonnet to buzz even more noisily than usual..

Religion divides us, while it is our human characteristics that bind us to each other..