Absolutely no religious rites of any kind, relating to any religious faith, should be associated with my funeral.

There is no reason to assume that the universe has the slightest interest in intelligence—or even in life. Both may be random accidental by-products of its operations like the beautiful patterns on a butterfly's wings. The insect would fly just as well without them.

The only way to define your limits is by going beyond them.

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.

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.

Behind every man now alive stand thirty ghosts, for that is the ratio by which the dead outnumber the living.

If I didn't exist, I would have invented myself.