“Philosophy is at its heart always a meta-activity, stepping back to think about thinking. It thinks not only about what our obligations are, but also about the concept of obligation; not only about what is just, but also about the concept of justice; not only about what it is rational to do or believe, but also about the concept of the rational. This makes it difficult for some people to find their feet with philosophy, and it makes them impatient of it. To them, I repeat Wittgenstein’s advice concerning how philosophers should greet one another. He said they should say, ‘Take your time.”