By source do you mean way to know what is moral, or reason that there is a fact of the matter as to whether something is moral? I don't think one necessarily m

By source do you mean way to know what is moral, or reason that there is a fact of the matter as to whether something is moral? I don't think one necessarily must claim to know /why/ there is a fact of the matter as to what things are moral, in order to be justified in one's claim that there /is/ a fact of the matter? Moral nihilism can fall down a well. (Note: I mean moral nihilism, not moral nihilists. Rhetoric. I don't have much against nihilists, except that I believe they are incorrect, and it is sometimes kind of scary to need to trust them?)