It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be. This, in turn, means that our statesmen, our businessmen, our every man must take on a science fictional way of thinking.

What lasts in the reader's mind is not the phrase but the effect the phrase created: laughter, tears, pain, joy. If the phrase is not affecting the reader, what's it doing there? Make it do its job or cut it without mercy or remorse.

When I die I won't go to heaven or hell; there will just be nothingness.

[Social] science fiction is that branch of literature which is concerned with the impact of scientific advance on human beings.

They won't listen. Do you know why? Because they have certain fixed notions about the past. Any change would be blasphemy in their eyes, even if it were the truth. They don't want the truth; they want their traditions.

The human brain, then, is the most complicated organization of matter that we know.

A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. [The Second Law of Robotics]