  The biggest problem for reforming definitions is that they suggest that normativity is somehow dispensable to morality. But as Joyce (2000, Ch. 1) argues, normativity is a non-negotiable commitment of our moral discourse. If the only kinds of facts that exist are natural, and natural facts are not a source of reasons for everyone, then, argues Joyce, this amounts to a proof that moral facts don’t exist. Reformers may respond by calling into question Joyce’s notion of “non-negotiable” commitments. For Joyce, it is obvious that facts that do not provide reasons for everyone are, ipso facto, not moral facts. But it is controversial whether any of our concepts have commitments that are non-negotiable in this way (cf. Prinzing 2017).