In this article I make two main critiques of Kaczmarek and Beard's article ‘Human Extinction and Our Obligations to the Past’. First, I argue that there is an ambiguity in what it means to realise the benefits of a sacrifice and that this ambiguity affects the persuasiveness of the authors’ arguments and responses to various objections to their view. Second, I argue that their core argument against human extinction depends on an unsupported assumption about the existence and importance of existential benefits.

This paper explores what could be wrong with the fact of human extinction. I first present four reasons why we might consider human extinction to be wrong: (1) it would prevent millions of people from being born; (2) it would mean the loss of rational life and civilization; (3) it would cause existing people to suffer pain or death; (4) it would involve various psychological traumas. I argue that looking at the question from a contractualist perspective, only reasons (3) and (4) are admissible. I then consider what implications this limitation on reasons has for the wrongfulness of various forms of human extinction.