Why derek parfit had reasons to accept the repugnant conclusion

Derek Parfit has famously pointed out that ‘total’ utilitarian views, such as classical hedonistic utilitarianism, lead to the conclusion that, to each population of quite happy persons there corresponds a more extensive population with people living lives just worth living, which is (on the whole) better. In particular, for any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living. This world is better if the sum total of well being is great enough, and it is great enough if only many enough sentient beings inhabit it. This conclusion has been considered by Parfit and others to be ‘repugnant’.

Utilitas

The Repugnant Conclusion is an implication of some approaches to population ethics. It states, in Derek Parfit's original formulation, For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living. (Parfit 1984: 388)

The spectre of the repugnant conclusion and the search for a population axiology that avoids it has endured as a focus of population ethics. This is in part because the repugnant conclusion is often interpreted as a defining problem for totalism, while the implications of averagism and related views are taken to illustrate the theoretical cost of avoiding the repugnant conclusion. However, we show that this interpretation cannot be sustained unless one focuses only on a special case of the repugnant conclusion: namely, the subset of instances of the repugnant conclusion where there is no portion of the population unaffected by the choice between population outcomes (as in Derek Parfit’s original illustration). To avoid an inappropriate focus on only this proper subset of instances of the repugnant conclusion, we formulate a general characterization of the repugnant conclusion. We then prove formally that all leading welfarist axiologies imply this conclusion, including averagism and Ng’s Theory X0 , including probabilistic and ‘very repugnant’ variants that involve the addition of negative lives. We then prove that the full range of axiologies considered by population ethics each imply an extended version of the repugnant conclusion, including axiologies that are incomplete, intransitive, rank-dependent, person-affecting, and/or pluralist. The upshot is that the repugnant conclusion does not ultimately tell against any approach to axiology, and the methodological requirement to avoid the repugnant conclusion should be dropped from population axiology.

Total utilitarianism implies Parfit's repugnant conclusion. For any world (A) containing ten billion very happy people, there is a better world (Z) where a vast number of people have lives barely worth living. One common response is to claim that life in Parfit's Z is better than he suggests, and thus that his conclusion is not repugnant. This paper shows that this strategy cannot succeeed. Total utilitarianism also implies a reverse repugnant conclusion. For any world (A-minus) where ten billion people have lives of excrutiating agony, there is a worse world (Z-minus)

2013

Derek Parfit originally formulated the Repugnant Conclusion as follows: " For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living " (1984: 388). The blocks in Figure 1 represent two populations, A and Z. The width of each block shows the number of people in the corresponding population, the height shows their lifetime quality of life. All the people in Figure 1 enjoy positive welfare or, as we also could put it, have lives worth living (see well-being). People's welfare is much lower in Z than in A, but since there are many more people in Z, there is a greater quantity of welfare in Z as compared to A. Consequently, although the people in A lead very good lives and the people in Z have lives only barely worth living, Z is nevertheless better than A according to, for example, classical Utilitarianism (see utilitarianism). The Repugnant Conclusion highlights a problem in an area of ethics which has become known as population ethics. The last decades have witnessed an increasing philosophical interest in questions such as " Is it possible to make the world a better place by creating more people? " and " Is there a moral obligation to have children? " The main problem is to find an adequate theory about the moral value of states of affairs where the number of people, their welfare, and their identities may vary. Since, arguably, any reasonable moral theory has to take such aspects of possible states of affairs into account when determining the normative status of actions, the study of population ethics is of general import for moral theory (see also intergenerational ethics; population; potential persons). As the name indicates, Parfit finds the Repugnant Conclusion unacceptable, and most philosophers seem to agree. It has been surprisingly difficult, however, to find a theory that avoids it without implying other counterintuitive conclusions. Thus,

Theoria

The aim of this paper is to discuss the plausibility of a certain position in the philosophical literature within which the Repugnant Conclusion is treated, not as repugnant, but as an acceptable implication of the total welfare principle. I will confine myself to focus primarily on Torbjorn Tannsjo's presentation. First, I reconstruct Tannsjo's view concerning the repugnance of the RC in two arguments. The first argument is criticized for (a) addressing the wrong comparison, (b) relying on the controversial claim that the privileged people in our actual world only have lives barely worth living and (c) that Tannsjo's identification between Z-lives and privileged lives is restricted to certain versions of the notion 'barely worth living' -a restriction that weakens the force of the argument. The second argument is criticized because some of it premises entailed (b) and (d) for its implausible claim that non-imaginable outcomes cannot be compared.

2021

Blocking the Continuum Argument for the Repugnant Conclusion by an appeal to incommensurabilities in value, as suggested in Parfit (2016), is an attractive option. But incommensurabilities (‘imprecise equalities’ in Parfit’s terminology) that need to be posited to achieve this result have to be very thoroughgoing – ‘persistent’ in the sense to be explained. While this persistency is highly atypical, it can be explained if incommensurability is interpreted on the lines of the fitting-attitudes analysis of value, as permissibility of divergent attitudes towards the items that are being compared. More precisely, it can be interpreted as parity – as the permissibility of opposing preferences with respect to the compared items. This account makes room for the persistency phenomena. Nevertheless, some of Parfit’s substantive value assumptions must be given up, to avoid implausible implications. In particular, his Simple View regarding the marginal value of added lives cannot be retained.