Yes, I understand that. The issue is that not all disagreements are about what you call "matters of opinion" (and thus faultless [1]). (And even when they are,

Yes, I understand that. The issue is that not all disagreements are about what you call "matters of opinion" (and thus faultless [1]). (And even when they are, one can give an approximate answer that filters out a bunch of alternative opinions on the matter: for example, it seems like a waiter in NYC should not be paid less than a certain a amount, let's say, the average it takes for someone in NYC in the person's social strata to pay rent and be able to eat and go to work each day). The issue really comes up when one takes all disagreements to take this form, which is, I think, what this thread was initially about (then the GGP asked why we should care about the facts at all). [1]: https://www.jstor.org/stable/4545405 https://www.jstor.org/stable/4545405