without being sure of something, we can not begin to think about everything elses

doubt is a skill. credulity ,by contrast, appears to be something very like an instinct

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

Unlike earlier thinkers, who had sought to improve their accuracy by getting rid of error, Laplace realized that you should try to get more error: aggregate enough flawed data, and you get a glimpse of the truth. "The genius of statistics, as Laplace defined it, was that it did not ignore errors; it quantified them," the writer Louis Menand observed. "...The right answer is, in a sense, a function of the mistakes.

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

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?

both doubt and certainty are as contagious as the common cold