All major theories in population ethics tend to produce counterintuitive results. Total utilitarianism, or
totalism, aims to maximize the total sum of wellbeing in the world, as constituted by the number of individuals multiplied by their average quality of life. Consequently, totalists hold that a state of affairs can be improved either by increasing the average wellbeing level of the existing population or by increasing the population size through the addition of individuals with positive wellbeing. Greaves formally defines totalism as follows: A state of affairs "A is better than B if total well-being in A is higher than total well-being in B. A and B are equally good if total well-being in A is equal to total well-being in B." Greaves writes that Parfit searched for a way to avoid the repugnant conclusion, but that he The impossibility theorems in population ethics highlight the difficulty of avoiding the repugnant conclusion without giving up even more fundamental axioms in ethics and rationality. In light of this, several prominent academics have come to accept and even defend the repugnant conclusion, including philosophers
Torbjörn Tannsjö and
Michael Huemer, because this strategy avoids all the impossibility theorems. This follows from averagism since adding a small number of tortured people with horrible lives to a population diminishes the average wellbeing level by less, than would creating a sufficiently large number of people with positive lives, as long as their wellbeing is below average.
Person-affecting views Some people have the intuition that, all else being equal, adding a happy person to the population does not constitute an improvement to the overall state of the world. This intuition is captured by the person-affecting class of views in population ethics, and is often expressed in
Jan Narveson's words that "we are in favour of making people happy, but neutral about making happy people". Person-affecting views can be seen as a revision of
total utilitarianism in which the "scope of the aggregation" is changed from all individuals who would exist to a subset of those individuals (though the details of this vary). They avoid the repugnant conclusion, because they deny that a loss of wellbeing in the present generation can be compensated by bringing additional people into existence that would enjoy a high wellbeing. Person-affecting views can be characterized by the following two claims: first, the
person-affecting restriction holds that doing something morally good or bad requires it to be good or bad
for someone; and second, the
incomparability of non-existence holds that existing and non-existing are incomparable, which implies that it cannot be good or bad for someone to come into existence.
Jeff McMahan describes the asymmetry by saying that One response to this challenge has been to reject this asymmetry and claim that just as we have reasons not to bring into existence a being who will have a bad life, we have reasons to bring into existence a being who will have a good life. Critics of this view can claim either that our reasons not to bring into existence unhappy lives are stronger than our reasons to create happy lives, or that while we should avoid creating unhappy lives we have no reason to create happy lives. While this claim has been defended from different view points, it is the one that would be favored especially by
negative consequentialism and other
suffering-focused views. == Practical relevance ==