Nonsense! The most hopelessly stupid man is he who is not aware that he is wise.

Life is glorious when it is happy; days are carefree when they are happy; the interplay of thought and imagination is far superior to that of muscle and sinew.

Humanity is cutting down its forests, apparently oblivious to the fact that we may not be able to live without them.

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

Even as a youngster, though, I could not bring myself to believe that if knowledge presented danger, the solution was ignorance. To me, it always seemed that the solution had to be wisdom. You did not refuse to look at danger, rather you learned how to handle it safely.

Humanity has the stars in its future, and that future is too important to be lost under the burden of juvenile folly and ignorant superstition.

Science is a set of rules to keep us from telling lies to each other. All scientists really have is a reputation for telling the truth.