Regret doesn't remind us that we did badly, it reminds us that we know that we could do better.

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.

both doubt and certainty are as contagious as the common cold

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?

Wow. I don't know. Maybe I'm wrong.

The inability to experience regret is one of the diagnostic characteristics of sociopaths.

First, philosophy concerns itself with all kinds of issues that don't get much airtime in day-to-day life. What's the nature of reality? Can we ever truly know anything, and if so, how? What does it mean to be a moral agent? And while we're at it, is there any such thing as agency anyway?