Unfortunately, in many cases, people who write science fiction violate the laws of nature, not because they want to make a point, but because they don't know what the laws of nature are.

People who think they know everything are a great annoyance to those of us who do.

The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.

When stupidity is considered patriotism, it is unsafe to be intelligent.

So the universe is not quite as you thought it was. You'd better rearrange your beliefs, then. Because you certainly can't rearrange the universe.

In life, unlike chess, the game continues after checkmate.

People think of education as something that they can finish.

There are no nations! There is only humanity. And if we don't come to understand that right soon, there will be no nations, because there will be no humanity.

A robot may not injure a human being, or, through inaction, allow a human being to come to harm.

Violence is the last refuge of the incompetent.

A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.

At times you inhale a fragrance that transports you to another world.

It’s lovely when writers I like like each other.

Gift ain't what you take by effort, as swag ain't what you worthy have.

I wonder if these death penalty proponents would still hold that it's worth some risk of error if it were their loved one who was murdered by the state, though innocent.

Courage isn't the absence of fear, but a decision that what we want is more important than what we are afraid of.

If America could get along with Russia - and by the way, China and Japan and everyone. If we could get along, it would be a positive thing, not a negative thing.

If you want to really understand about a tumor, you've got be be a tumor.

Holy water at my wrists and behind my ears; my version of Eau de Don'tbiteme

You managed not to get eaten then?

If you get hold of a head of hair on somebody you've never seen before, cut beautiful shapes, cut beautiful architectural angles and she walks out looking so different - I think that's masterful.