Abstract

This thesis deals with population axiology, that is, 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 axiology is of general import for moral theory. ;There has been a search underway for the last thirty years or so for a theory that can accommodate our intuitions in population axiology. The object of this search has proved surprisingly elusive. The classical moral theories in the literature all have perplexing implications in this area. Classical Utilitarianism, for instance, implies that it could be better to expand a population even if everyone in the resulting population would be much worse off than in the original. ;A number of population axiologies have been proposed in the literature that purport to avoid counter-intuitive implications such as the one mentioned above. The suggestions range from introducing novel ways of aggregating welfare into a measure of value, revising the notion of a life worth living, challenging the way we can compare and measure welfare, to counting people's welfare differently depending on the temporal location or the modal features of their lives. We investigate the concepts and assumptions involved in these theories as well as their implications for population axiology. ;In our discussion, we propose a number of intuitively appealing and logically weak adequacy conditions for an acceptable population axiology. In the last chapter, we consider whether it is possible to find a population axiology that satisfies all of these conditions. We prove that no such axiology exists