It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars.

Religion is a byproduct of fear.

We seldom stop to think that we are still creatures of the sea, able to leave it only because, from birth to death, we wear the water-filled space suits of our skins.

We stand now at the turning point between two eras. Behind us is a past to which we can never return...

But he knew well enough that any man in the right circumstances could be dehumanised by panic.

The difference between machines and human beings is that human beings can be reproduced by unskilled labour.

Sometimes a decision has to be made by a single individual, who has the authority to enforce it. That's why you need a captain. You can't run a ship by a committee-at least not all the time.