  Strictly speaking, a metaphysical criterion of identity has no direct implications whatsoever for normative matters, simply because what is the case implies nothing about what ought to be the case. What people who seek a relation between identity and ethics typically do, then,  is appeal to considerations of identity to fill in some key blank  regarding what the  ethically significant metaphysical units are. In other words, certain conclusions about identity are taken to  inform us as to just what unifies the targets of prudential and moral theorizing. Consider prudence, for example. In deliberating about  what is in my best interest, what is needed is some conception of the scope of the “my” in question, i.e., what unit  my deliberations are to cover. Similarly, with respect to moral  responsibility, we need to know whether the agent subject to  praise or blame for some action is part of the same unit as the agent who performed that action.