I don't think there is such a thing as as a real prophet. You can never predict the future. We know why now, of course; chaos theory, which I got very interested in, shows you can never predict the future.

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.

The exploration of the planets is now closer to us in time than the exploration of Africa by Stanley and Livingstone.

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

Before the current decade ends, fee-paying passengers will be experiencing suborbital flights aboard privately funded vehicles. . . . It won't be too long before bright young men and women set their eyes on careers in Earth orbit and say: "I want to work 200 kilometers from home-straight up!"

There is the possibility that humankind can outgrow its infantile tendencies, as I suggested in 'Childhood's End.' But it is amazing how childishly gullible humans are.

I will not be afraid because I understand ... And understanding is happiness.