The Normative Contingency Thesis (NCT) is a compelling objection to Moral Realism.

Pro and I are on the same page here: the debate concerns the NCT rather than any defense of moral realism per se. Pro rightly admits he has first principles which he operates on, and it seems now his task is differentiate or rather validate his own first principles over the first principles that lead to a form of moral realism. Another thing, Pro refers to “my case” which I believe is essentially just a deconstruction of his case. This is evident when Pro writes that my argument is true “but it does nothing to help Con’s case.” My case is entirely in response to Pro’s and we need to keep this in mind. With that said, Pro brings up some fascinating points with this argument that I have a lot to say about. Proof/Truth Pro argues for sharp divide between truth on one hand and provability on the other. This leads to an interesting comment on nihilism that threw me for a loop: “For the nihilist, "I don't know" cannot be countered by questions about how he knows that he knows nothing--the nihilist is not making an argument or attempting to prove that he knows nothing; rather, he is exposing a fatal flaw in the structure of justificationalism which makes certainty impossible. Really, what is being communicated is that the nihilist commits to to the truth of the proposition that he knows nothing while being unable to demonstrate it, since the only condition that would demonstrate nihilism to be true is that it cannot be proven.” Let me first mention that in breaking down a case you are invoking what you believe to be true and exposing what one believes to be either logical – formal or informal – fallacies in that argument, among other things. Pro mentions “the truth of the proposition…” would this not imply certainty? Can we be certain that there is no certainty? Or can certainty only be gauged in percentage terms? Can we certainly accept non-certain conclusions? Pro justifies the position based on its ability to expose a flaw in justificationalism. “Exposing a flaw” implies appealing to objective standards of logic. Really, what Pro seems to be stressing here is the inability to have proof which I’ll return to later. I want to get back to the original thesis of the NCT. Let’s revisit it as phrased in Pro’s tl;dr in R2: “You can keep asking people to warrant their ethical beliefs, and they'll eventually come down to some meta-ethical linchpin, e.g., "human life has value", which we have no reason to accept as true. They'll say it's useful, or that it "just is" true, or that it's true if you just define morality in a way that makes it so, but regression/contingency shows that even first principles are quick hide behind their natural subjectivity when put to the test.” As mentioned, first principles are the starting points of reason. No one is claiming that they are discovered or proven in the scientific sense. Pro writes “…which we have no reason to accept as true.” Pro uses his own first principle certainties to counter first principles that he doesn’t believe in. That’s fine, much of philosophy is after all an attempt to grasp onto an underlying metaphysical reality. Pro’s task here is to be able to mark his own first principles as fundamentally superior to the first principles that form his nihilism. Let me first say that this goal already sounds bizarre in light of Pro’s view that nihilism is a rejection of truth or objective better-ness (Pro will certainly object, I won’t pretend to really understand his methods.) Assorted objections a) I reject a sharp distinction between logic and ethics. There are numerous different types of logic, and unfortunately logic is not a field I’m particularly educated in but it’s undergone enormous changes in the past century. Pro cites 3 basic ethical propositions earlier in the response (see Aristotelian logic) and 2 of those have been challenged by other logical systems often containing varying levels of truth values rather than a strict binary system. The law of identity (A=A) is the “logical certainty” we’re left with. With ethics you do have widespread shared universal intuitions on certain subjects, and you can debate the use of the word “objective morality” from an academic standpoint but there’s absolutely a generally shared conception of the proper ends of moral philosophy. All else being equal, rational individuals would like to see human beings as free, intelligent, healthy, and self-actualized even if these concepts entail very different things to people. b) Let’s revisit the thesis stated in the title: “The NCT is a compelling objection to moral realism.” You are Pro and I am Con. I am not responsible for defending moral realism per se. I am also not forced to reject the notion of normative contingency which I accept in description – really the question is whether the NCT is a compelling objection. Nothing more, nothing less. Lastly, Pro writes “But, since realism relies on mind-independent features of the world for verification, and the only things which produce the value-axioms (which supposedly come from the world) are the individuals who posit them/the other parties who agree, normative contingency is fundamentally devastating to the realist thesis.” And why can’t these individuals be right? Does nihilism not attempt to grasp onto underlying truths (or facts or non-truths? I still haven’t figured it out) about the universe? Conclusion I want to present some of my moral ideas and tie them back into the discussion. I believe in a telic view of human nature. That is to say, that there is a certain proper path that humans can develop toward that can lead to a sense of self-actualization or just living well. Of course this isn’t a scientific view, and I know that Pro sharply rejects any notion of a teleological view of human nature. Our respective differences are derived from differences in first principles, and since these first principles comprise the basis of our worldviews it’s nearly impossible to have a rational discussion about them. Perhaps literature can illustrate certain themes (Pro might be more partial to existentialism) but in the end its our own best ideas – which may be either true or false – to grasp onto an underlying metaphysical reality. Pro objects that mine are unfounded while refusing to examine his own. In order for Pro’s case to work he must show that the NCT is a sound criticism in terms of its moral content and that his first principles are essentially more objective sound than mine (note the odd relationship with nihilism.) If Pro simply concedes that everything is subjective and wallows in skepticism he can’t possibly make his case and fulfill his BOP. As for Godel, he too relied on first principles to make his conclusions that all non-trivial axiomatic systems cannot verify themselves but furthermore this isn’t what realists are saying. Rather, it’s this intuitive view or possibly a “best guess” that validates it as with Pro’s demands for bona fide certainty and high verification standards. I hope I addressed it all and if I missed anything make sure to remind me in R4. Back to you, Pro.