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 nuisance of itself by asking 'Why?'. To stop this nuisance society has invented a marvellous system called education which, for the majority of people, brings to an end their desire to ask that question. The few failures of this system are known as scientists.

The true contrast between science and religion is that science unites the world and makes it possible for people of widely differing backgrounds to work together and to cooperate. Religion, on the other hand, by its very claim to know “The Truth” through “revelation,” is inherently divisive and a creator of separatism and hostility.

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. The homogeneity assumption may then be put in the form: 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 at any time.

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 before… It is very hard to realize how total a change in outlook Isaac Newton has produced.

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 less irrespective of the stuff we don't know about, we can make certain useful deductions.

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 way where you can say something without knowing everything.

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