 Objections to proposals that rely on a non-comparative concept of harm to solve the nonidentity problem focus on whether that concept itself can be clearly worked out. Thus, it may be hard to see how one whose wellbeing has been maximized can at the same time have been harmed in any sense of that term that remains clearly within our grasp. Moreover, as Parfit suggests, even if we think it correct on occasion to say that a person who has not been made worse off has been “harmed,” we may still be unclear whether that person has been harmed in a “morally relevant sense” (Parfit 1987, 374). Finally, there is the question of limits: what adverse conditions are to appear on the non-comparative harm list? What is the threshold level below which existence counts as harm? What is “normal”? And are we really willing to eliminate or at least to mix up the distinction we think we now can so cleanly draw between, e.g., the case in which opening up one’s chest to expose the heart serves no purpose at all and the case in which opening up one’s chest to expose the heart is an essential part of an open-heart procedure that is itself both necessary and sufficient to restore life and health? For critical discussion of the non-comparative account of harm, see Gardner 2015.