Earlier quoted context omitted.
> Regarding subjectivity, if you assert morality is subjective, you don't have a leg to stand on in saying I was wrong. Well, subjectivity doesn't mean you're right in the objective sense. See, you opened your comment with a logical trick to prove the correctness of what you were about to say before you even said it, and you did so by deciding that there are intrinsically right and wrong moral decisions. I think that…
I agree with the logic trick part. To say something is undecidable is to make an objective claim. However, at the point where you want to say someone should or should not do something the subjective morality comes back to bite you (saying curi's trick was underhanded). I think this is curi's point. All you can really do with subjective morality is describe your rationale for why you do what you do, and hope the other…
You can also remove contradictions locally if you find any. If you want, you can say that is based on the common foundation "if two ideas contradict, at least one is false". But the point is, you see a contradiction, you know at least one of the ideas is mistaken in some way, so you know there's room for improvement there, until you come up with some changes that remove the contradiction.