I don't believe in an afterlife, so I don't have to spend my whole life fearing hell, or fearing heaven even more. For whatever the tortures of hell, I think the boredom of heaven would be even worse.

When, however, the lay public rallies round an idea that is denounced by distinguished but elderly scientists and supports that idea with great fervor and emotion - the distinguished but elderly scientists are then, after all, probably right.

There’s nothing to it. All you have to do is take a close look at yourself and you will understand everyone else. We’re in no way different ourselves... You show me someone who can’t understand people and I’ll show you someone who has built up a false image of himself.

Married life had taught Toran the futility of arguing with a female in a dark-brown mood.

A robot must obey the orders given it by human beings except where such orders would conflict with the First Law. [The Second Law of Robotics]

You don't have to be able to lay eggs to know when one of them is rotten.

Despite all that education and experience can do, I retain a certain level of unsophistication that I cannot eradicate and that my friends find amusing. In fact, I think I sometimes detect conspiratorial plottings among my friends to protect me against my own lack of sophistication. I don't mind. I suspect that I am never quite as unsophisticated as they think I am, but I don't mind.