Don't mess up the environment until you're quite sure what you're doing.

One of the biggest roles of science fiction is to prepare people to accept the future without pain and to encourage a flexibility of the mind. Politicians should read science fiction, not westerns and detective stories.

The moment when one first meets a great work of art has an impact that can never again be recaptured.

Human judges can show mercy. But against the laws of nature, there is no appeal.

The time was fast approaching when Earth, like all mothers, must say farewell to her children.

One of the great tragedies of mankind is that morality has been hijacked by religion. So now people assume that religion and morality have a necessary connection. But the basis of morality is really very simple and doesn't require religion at all.

As three laws were good enough for Newton, I have modestly decided to stop there.