I am an optimist. Anyone interested in the future has to be otherwise he would simply shoot himself.

To find anything comparable with our forthcoming ventures into space, we must go back far beyond Columbus, far beyond Odysseus-far, indeed, beyond the first ape-man. We must contemplate the moment, now irrevocably lost in the mists of time, when the ancestor off all of us came crawling out of the sea.

Until we get rid of religion, we won't be able to conduct the search for God.

Now I understand,” said the last man.

When you finally understand the universe, it will not only be stranger than you imagine, it will be stranger than you can imagine.

As our own species is in the process of proving, one cannot have superior science and inferior morals. The combination is unstable and self-destroying.

The future is not to be forecast, but created.