In Derek Parfit's original formulation the Repugnant Conclusion is characterized 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” (Parfit 1984). The Repugnant Conclusion highlights a problem in an area of ethics which has become known as population ethics . The (...) last three decades have witnessed an increasing philosophical interest in questions such as “Is it possible to make the world a better place by creating additional happy creatures?” and “Is there a moral obligation to have children?” The main problem has been to find an adequate theory about the moral value of states of affairs where the number of people, the quality of their lives, and their identities may vary. Since, arguably, any reasonable moral theory has to take these 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. As the name indicates, Parfit finds the Repugnant Conclusion unacceptable and many philosophers agree. However, it has been surprisingly difficult to find a theory that avoids the Repugnant Conclusion without implying other equally counterintuitive conclusions. Thus, the question as to how the Repugnant Conclusion should be dealt with and, more generally, what it shows about the nature of ethics has turned the conclusion into one of the cardinal challenges of modern ethics. (shrink)

In Reasons and Persons, Derek Parfit cannot find a theory of well-being that solves the Non-Identity Problem, the Repugnant Conclusion, the Absurd Conclusion, and all forms of the Mere Addition Paradox. I describe a “Quasi-Maximizing” theory that solves them. This theory includes (i) the denial that being better than is transitive and (ii) the “Conflation Principle,” according to which alternative B is hedonically better than alternative C if it would be better for someone to have all the B-experiences. (i) entails (...) that Quasi-Maximization is not a maximizing theory, but (ii) ensures that its evaluations will often coincide with such theories. (shrink)

On an act utilitarian view it is morally permissible if not obligatory to choose to perform an action which contributes as much as any other action to the total happiness of all those capable of enjoying happiness. As the view has just been stated, however, there is some question of how we are to understand the phrase “all those capable of enjoying happiness”. For even leaving aside the possibility that animals or spirits might be included, there is still the matter (...) of the size of the population of humans “capable of enjoying happiness”. Furthermore, among our ethical decisions themselves are decisions which would cause a decrease or increase in population and which in perhaps even more specific ways determine the applicability of this phrase “all those capable of enjoying happiness”. According to the socalled classical or total utilitarian principle, the phrase in question is understood as describing some population whose existence will enable one to maximize the net amount of happiness. For on the classical principle what one is obligated to do is simply to maximize net happiness. (shrink)