This paper offers a unified explanation for the procreation asymmetry and the non-identity thesis – two of the most intractable puzzles in population ethics. According to the procreation asymmetry, there are moral reasons not to create lives that are not worth living but no moral reasons to create lives that are worth living. I explain the procreation asymmetry by arguing that there are moral reasons to prevent the bad, but no moral reasons to promote the good. Various explanations for the procreation asymmetry have failed to explain the non-identity thesis: if one could create a person with a good life or a different person with a better life, one has a moral reason to create the better life. I argue that reflections on the misfortune of unfulfilled potential allow us to circumvent the non-identity problem.

It is frequently claimed that breeding animals that we know will have unavoidable health problems is at least prima facie wrong, because it harms the animals concerned. However, if we take ‘harm’ to mean ‘makes worse off’, this claim appears false. Breeding an animal that will have unavoidable health problems does not make any particular individual animal worse off, since an animal bred without such problems would be a different individual animal. Yet, the intuition that there is something ethically wrong about breeding animals — such as purebred pedigree dogs — in ways that seem negatively to affect welfare remains powerful. In this paper, an animal version of what is sometimes called the non-identity problem is explored, along with a number of possible ways of understanding what might be wrong with such breeding practices, if it is not that they harm the animal itself. These possibilities include harms to others, placeholder arguments, non-comparative ideas of harm, an ‘impersonal’ approach, and concerns about human attitudes and dispositions.

Can appealing to children’s rights help to solve the non-identity problem in cases of procreation? A number of philosophers have answered affirmatively, arguing that even if children cannot be harmed by being born into disadvantaged conditions, they may nevertheless be wronged if those conditions fail to meet a minimal standard of decency to which all children are putatively entitled. This paper defends the tenability of this view by outlining and responding to five prominent objections that have been raised against it in the contemporary literature: (1) the identifiability objection; (2) the non-existence objection; (3) the waiving of rights objection, (4) the lack of legitimate complaint objection; and (5) the unfairness objection.

A number of philosophers have resisted impersonal explanations of our obligation to mitigate climate change, and have developed accounts according to which these obligations are explained by human rights or harm-based considerations. In this paper I argue that several of these attempts to explain our mitigation obligations without appealing to impersonal factors fail, since they either cannot account for a plausibly robust obligation to mitigate, or have implausible implications in other cases. I conclude that despite the appeal of the motivations for rejecting the appeal to impersonal factors, such factors must play a prominent role in explaining our mitigation obligations.

In this article we distinguish two versions of the non-identity problem: one involving positive well-being and one involving negative well-being. Intuitively, there seems to be a difference between the two versions of the problem. In the negative case it is clear that one ought to cause the better-off person to exist. However, it has recently been suggested that this is not so in the positive case. We argue that such an asymmetrical treatment of the two versions should be rejected and that this is evidence against views according to which it is permissible to cause the less well-off person to exist in the positive non-identity case.