 The need to address not just the nonidentity problem but the full range of population problems leads Temkin as well to recognize impersonal as well as person-based values. Finding that terminology itself unenlightening, Temkin describes what he calls the internal aspects view of when one world, or outcome, is morally better than another as well as what he calls the essentially comparative view (Temkin 2012, 363–456). We take for granted that our ultimate goal is to evaluate a given world for its moral betterness against other worlds. But on the internal aspects view the good of that one world as compared against a second world can be discerned without consideration of what is going on in still other worlds. Totalism is a paradigm instance of the internal aspects view (though not a view Temkin, given his emphasis on equality, human flourishing and other values, himself endorses). In contrast, on the essentially comparative view we cannot complete the evaluation of one world against another in the absence of a potentially extensive inter-world comparison. Moreover, we find that when we engage in such an extensive comparison it is the person-based features of those worlds that bear most clearly on our evaluation. Thus, suppose that the only (potentially morally relevant) difference between two worlds is the addition to the second world of a single person whose existence is worth having.  On the essentially comparative view, that second world may nonetheless turn out to be morally worse than the first, if that same person exists in a third world and there has a still better existence (Temkin 2012, 364–400).