There is a time to admire the grace and persuasive power of an influential idea, and there is a time to fear its hold over us. The time to worry is when the idea is so widely shared that we no longer even notice it, when it is so deeply rooted that it feels to us like plain common sense. At the point when objections are not answered anymore because they are no longer even raised, we are not in control: we do not have the idea; it has us.