Santa keeps tabs on what you do and when you sleep. He will punish or reward you on the basis of your performance. So you should be good for purely moral motives. The trouble, again, is that after having given a variety of non-moral, strictly self-interested reasons to act, it is a perfect non sequitur to conclude that we must act on the basis of purely moral motives. In fact, if we’re right, the Santa myth undermines the idea that we should act on the basis of our moral reasons. By accepting the Santa myth, then, we nearly ensure that we will not be good.