both doubt and certainty are as contagious as the common cold

The miracle of your mind isn't that you can see the world as it is. It's that you can see the world as it isn't.

The kinds of things that we can make mistakes about are essentially unlimited in number.

If you want to live a life free of regret, there is an option open to you. It's called a lobotomy.

wrongness always seems to come at us from left field - that is, from outside ourselves. But the reality could hardly be more different. Error is the ultimate inside job. Yes, the world can be profoundly confusing; and yes, other people can mislead or deceive you. In the end, though, nobody but you can choose to believe your own beliefs.

Error ... is less an intellectual problem than an existential one - a crisis not in what we know, but in who we are. We hear something of that identity crisis in the questions we ask ourselves in the aftemath of error: What was I thinking? How could I have done that?

Of all the things we are wrong about, error might well top the list ... We are wrong about what it means to be wrong. Far from being a sign of intellectual inferiority, the capacity to err is crucial to human cognition. Far from being a moral flaw, it is inextricable from some of our most humane and honourable qualities: empathy, optimism, imagination, conviction, and courage. And far from being a mark of indifference or intolerance, wrongness is a vital part of how we learn and change. Thanks to error, we can revise our understanding of ourselves and amend our ideas about the world.