Abstract

Secular arguments for equal and exclusively human worth generally tend to follow one of two strategies. One, which has recently gained renewed attention because of a novel argument by S. Matthew Liao, aims to directly ground worth in an intrinsic property that all humans have in common, whereas the other concedes that there is no morally relevant intrinsic difference between all humans and all other animals, and instead appeals to the membership of all humans in a special kind. In this article, I argue that both strategies necessitate drawing a line that is both arbitrary and implausibly opens a moral gulf between individuals whose difference from one another in terms of empirical reality is entirely unremarkable, providing reasons to reject them that go beyond the standard objections in the literature. I conclude that, if all humans are to be included in the community of equals, we must lay to rest the idea that we can do so without also including a wide range of non-human animals.