When discussing theories of justice, most philosophers take the moral equality of human beings as their starting point. As Will Kymlicka says, in all contemporary plausible theories of justice, moral equality constitutes an "egalitarian plateau". 1 Arguably, the most prominent novel theory of justice in recent years is relational egalitarianism-a theory on which justice requires people to relate as equals. Relational egalitarians are no exception to Kymlicka's claim. They too start from the idea of moral equality. As one of us previously put it, "as a matter of fact, we are one another's moral equals and in relating as equals we honour that fact, and this is what grounds the ideal of relational egalitarianism". 2 Awkwardly, given this near-consensus, it has proved difficult to identify the properties in virtue of which all human beings, or at least those who are persons, are moral equals. Richard Arneson sums up the problem nicely:Either the proposed basis [the property, or properties, proposed to ground equal moral status] will turn out to vary by degree, and variations above the claimed threshold that establishes equality will give rise to inequality of moral considerability, or the proposed basis will turn out to be one that applies in an all-or-nothing fashion, and then it will turn out that the basis proposed as justifying equal moral considerability is too flimsy or insubstantial to do this justifying work. 3 1 Kymlicka 2002. But see Lippert-Rasmussen (2022a) on why this is confusing in the context of utilitarianism.