I think one can read that line to be about moral epistemology under a truly realist conception. It seems to match my reading of Peter Railton. Of course one needs to then argue why our imperfect attempts at value negotiations can give us information about the moral facts. This question becomes easier if one takes the moral facts to be constituted by some (potentially idealized) negotiation, which is the position of moral constructivisim. But constructivists wouldn’t say that morality is “discovered” by the process of negotiation.
I think one can read that line to be about moral epistemology under a truly realist conception. It seems to match my reading of Peter Railton. Of course one needs to then argue why our imperfect attempts at value negotiations can give us information about the moral facts.
This question becomes easier if one takes the moral facts to be constituted by some (potentially idealized) negotiation, which is the position of moral constructivisim. But constructivists wouldn’t say that morality is “discovered” by the process of negotiation.