Ought Implies Can

Too often ethical pronouncements have an air of hubris about them, as the pronouncer simply assumes we can do what he says we ought to do. By contrast, economics demands some humility. We always have to ask whether it’s humanly possible to do what the ethicists say we ought. To say we ought to do something we cannot do, in the sense that it won’t achieve our end, is to engage in a pointless exercise. If we cannot do it, to say that we ought to is to command the impossible.