Population Ethics

Abstract Population ethics concerns how to evaluate future populations regarding their goodness or choiceworthiness all things considered, or in terms of “socially preferred” to use a terminology more familiar in social choice theory and welfare economics. The field has been riddled with paradoxes and impossibility theorems which seem to show that people’s considered judgments are inconsistent in this area. This chapter considers what the impossibility theorems mean for the project of normative ethics and moral justification. It starts by presenting the impossibility result that involves the logically weakest and intuitively most compelling conditions and then discusses a few proposed but failed ways to avoid the theorem. Finally, the chapter turns to the implications of the impossibility theorem for moral justification and the project of normative ethics, including a novel argument for non-cognitivism and a new type of debunking argument.