Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Samantha Brennan

2nd Supervisor

John Thorp

Joint Supervisor


It used to be widely held that procreation does not need a justification, that its moral permissibility is simply obvious. But things are different now. And the change is largely due to a number of arguments from Benatar, Shiffrin and Velleman. In response to this background my dissertation offers the beginnings of the first systematic defense of procreation, one that consists in four articles. Along the way it draws some implications for parenting, for bioethics, for normative ethics, and for political philosophy.

Article one presents a novel argument that our lives may be much more valuable than we think, one that stems from an overlooked connection between lotteries, value and the non-identity problem. Article two explores the relationship between happiness research and procreation and blocks an argument that our lives are much worse than we think, not good enough to start. Article three argues that certain leftover problems in our attempt to justify procreation create a new argument for the doctrine of procreative beneficence and reveal that strict deontologists should probably become moderate deontologists – at least if they wish to justify creating persons. Article four formulates a new challenge for moral and political philosophy about the extent to which parents may transmit rejecting and potentially harmful attitudes to their sexual minority children. Here I show that the way in which parents reason about rejection has bearing on whether they should create.