It was the mark of a barbarian to destroy something one could not understand.

I'm quite fond of the writer who told a beginning author, "If you've got a message, use Western Union."

The choice, as Wells once said, is the Universe-or nothing. . . . The challenge of the great spaces between the worlds is a stupendous one; but if we fail to meet it, the story of our race will be drawing to its close. Humanity will have turned its back upon the still untrodden heights and will be descending again the long slope that stretches, across a thousand million years of time, down to the shores of the primeval sea.

Whether we are based on carbon or on silicon makes no fundamental difference we should each be treated with appropriate respect.

Religion is the most malevolent of all mind viruses.

Science fiction seldom attempts to predict the future. More often than not, it tries to prevent the future.

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