If there are any gods whose chief concern is man, they can't be very important gods.

I can never look now at the Milky Way without wondering from which of those banked clouds of stars the emissaries are coming. If you will pardon so commonplace a simile, we have set off the fire alarm and have nothing to do but to wait. I do not think we will have to wait for long.

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.

There's a passage about 'rivers of molten rock that wound their way... until they cooled and lay like twisted dragon-shapes vomited from the tormented earth.' That's a perfect description: how did Tolkien know, a quarter century before anyone ever saw a picture of Io? Talk about Nature imitating Art.

Every revolutionary idea seems to evoke three stages of reaction. They may be summed up by the phrases: 1- It's completely impossible. 2- It's possible, but it's not worth doing. 3- I said it was a good idea all along.

There is a special sadness in achievement, in the knowledge that a long-desired goal has been attained at last, and that life must now be shaped toward new ends.

It is vital to remember that information - in the sense of raw data - is not knowledge, that knowledge is not wisdom, and that wisdom is not foresight. But information is the first essential step to all of these.