To test a perfect theory with imperfect instruments did not impress the Greek philosophers as a valid way to gain knowledge.

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.

We are all tourists in history, and irony is what we win in wars.

Lobbyist influence comes from access, not money.

We conclude that hedge funds are far riskier and provide much lower returns than commonly supposed.

I don't throw my clothes out after one wear. Shocking, I know.

The only way to break the cycle of unwed motherhood, fatherless children, poverty, crime, and welfare is to recognize that welfare causes more problems than it cures.

The greatest misfortune of the wise man and the greatest unhappiness of the fool are based upon convention.

Friendship, Roland realized, was its very own kind of love.

Right now I'm 185, which is really good for me yet very hard for me to maintain. My weight seems high for the average woman, but I've got big bones and I'm maintaining muscle.

How superbly brave is the Englishman in the presence of the awfulest forms of danger and death; and how abject in the presence of any and all forms of hereditary rank.

I'm a moviemaker, not a documentarian. I try to hit the truth.