[English abstract] In his last metaethical statement, Parfit revisits his earlier arguments for non-metaphysical normative non-naturalism , and points to the possibility of convergence between his view and Railton's non-analytical normative naturalism. I examine the basis of this convergence claim and find it unpersuasive, mainly because if their views converge on the same position, Parfit's non-natural norms exist only as predicates. In order to avoid this consequence, he needs to present a reason for believing in the existence of normative properties (...) . There is an indispensability argument implicit in his text, with concepts of sui generis normative ground and necessity at its centre. I discuss their main features and present problems besetting these concepts. (shrink)