Wittgenstein, in his famous critique of philosophy, noted that the influence of an idea can be such that it alters the way that we see the world. “It is like a pair of glasses on our nose through which we see whatever we look at,” he said. “It never occurs to us to take them off.” This view of the power of an idea suggests that the interpretation of an event, and what response this event calls for, can depend upon the view one has of the world. A person who is naive about medical facts may, for example, interpret chest pain upon exertion as a sign that he is “overdoing it”; were he more medically knowledgeable, the same symptom might be interpreted as a possible indicator of coronary artery disease. The naive interpretation calls for rest; the informed interpretation calls for medical attention as well.