When I was young, the old regarded me as an outrageous young fellow, and now that I'm old the young regard me as an outrageous old fellow.

I have always thought it curious that, while most scientists claim to eschew religion, it actually dominates their thoughts more than it does the clergy.

It is a mistake to imagine that potentially great men are rare. It is the conditions that permit the promise of greatness to be fulfilled that are rare. What is so difficult to achieve is the cultural background that permits potential greatness to be converted into actual greatness.

On scientific grounds this big bang assumption is much less the palatable of the two. For it is an irrational process that cannot be described in scientific terms. . . . On philosophical grounds too I cannot see any good reason for preferring the big bang idea. Indeed it seems to me in the philosophical sense to be a distinctly unsatisfactory notion, since it puts the basic assumption out of sight where it can never be challenged by a direct appeal to observation.

The seemingly insuperable difficulties of deep-space travel suggest an intention to keep us fixed at home in our own solar system, and the physical nature of our part of the Universe, as well as the basic rules of physics and chemistry, have a warning look about them, like barriers designed to isolate intelligent life. This means that for us, unlike the situation for humble microorganisms, deep-space travel is probably a stark impossibility.

Words are like harpoons. Once they go in, they are very hard to pull out.

A superintellect has monkeyed with physics.