Aumann agreement theorem

If it was just a case of demonstrating it, that would be trivial. Even for an ethical position. The problem is convincing the other side, because that's where prior biases (fucking shoot me I am turning into EY) come in and make it more work than it should be. The flip side to that, of course, is that if your prior biases are in favour, it'll take far less work than it should to convince someone of it.

So I'm curious, why are you all so convinced that a "real" or "true" or "factual" point can be made in something like ethics or philosophy. (or am i misreading you). Just because you think something, and you are "rational" doesn't mean your something is logically correct, especially at the cost of other somethings.

You are definitely misreading me; I think that for any questions outside of the factual/naturalistic sphere, you just have to pick something to believe (preferably something that is logically consistent) and roll with it. These sorts of beliefs are categorically asserted without evidence and are dismissable without evidence.

You're getting into apples and oranges here. Unless you're going to pull a Sam Harris and argue that moral propositions are "facts" like physical law.

No, I didn't suggest you can treat moral judgements as "facts" - although you can demonstrate their consequences in a factual manner ("Gay marriage will lead to bestiality!!" - "Well, just watch it not do that."). But demonstrating something to be factually inaccurate, or demonstrating an ethical position to be badly thought out is fairly trivial next to convincing the believer that it's so.