You misunderstand moral relativism.

Moral relativists can have moral beliefs. They simply recognise that these are their own (very strongly held) opinions, rather than a reference to a universal moral code (like say, the Ten Commandments)

There are flaws in both my writing and the comment that critiques it.

There are various flavors of moral relativism. My comment criticizes one flavor of moral relativism without specifically identifying that I was criticizing meta-ethical relativism. I rewrote it in a sub-comment.

> Descriptive moral relativism holds only that people do, in fact, disagree fundamentally about what is moral, with no judgment being expressed on the desirability of this.

> Meta-ethical moral relativism holds that in such disagreements, nobody is objectively right or wrong.

> Normative moral relativism holds that because nobody is right or wrong, everyone ought to tolerate the behavior of others even when large disagreements about morality exist.

> Said concepts of the different intellectual movements involve considerable nuance and aren't absolute descriptions.

Quotes from Wikipedia [1], even though I prefer the Stanford Encyclopedia of Philosophy [2] for more detailed explanations.

[1] https://en.m.wikipedia.org/wiki/Moral_relativism

[2] https://plato.stanford.edu/entries/moral-relativism/#ForArg

As written, my comment is flawed. I should clarify what I meant. Let me rewrite it.

> moral relativism is intellectually bankrupt

There are three forms of moral relativism (see my other comment).

I agree with descriptive moral relativism in a sense, even though I think practically there are huge swaths of overlap between most well-known ethical/religious systems.

I don’t think I’m willing to categorically dismiss meta-ethical moral relativism (MMR), but in practice, I find it unpersuasive at best, delusional in most cases, and dishonest at worst.

Say you find a meta-ethical moral relativist (MMR). You present them with a set of hypothetical moral dilemmas. They will claim there is no objective ethics to guide us.

I accept this as a philosophical position; however, if that person were immersed in the dilemma and had to choose, they will choose. (Note: doing nothing is a choice.)

Their choice will reveal their “private” morality, which is certainly not completely relative. That person won’t agree with any ethics that say it is ok to kill them (under a scenario where they have done nothing wrong) for example. If it was a real situation, they would use various means at their disposal to protect their life: fleeing, fighting, or negotiating.

So, while perhaps the MMR person claims that it is ok for an ethical system to endorse killing them, but they would act differently from that belief.

> I don’t think I’m willing to categorically dismiss moral relativism,

I'm not a moral relativist, but I think invoking moral relativism here is somewhat beside the point – even if it is true that morality is (somehow) objective, that doesn't mean every moral dispute is resolvable in practice. There are plenty of factual questions which are impossible to answer – for example, what was Julius Caesar's last meal? Most people assume there must be an objective answer to that question, but nobody alive now knows it, and odds are we never will (speculation, guesswork and imagination aside). Well, in the same way, even if it is true that moral questions have objective answers (I for one believe they do), there is no guarantee we can actually know what the answers to all of them are.

Given that, it is reasonable for society to permit people with different moral views to coexist, rather than trying to force everyone to live by the same morality. Of course, there are certain moral issues on which society as a whole needs to take a side – the wrongfulness of murder, for example – but there are plenty of others on which it doesn't have to do so, and probably better not. I think, when it comes to questions of discrimination (on the basis of race/gender/etc), it is good that society seeks to prohibit it in public settings (government, the education system, the workplace, public accomodations, etc), but trying to outlaw it in private is a road to totalitarianism, and that's true even if private discrimination is objectively morally wrong.

Sometimes, an act itself can be morally wrong, but trying (too hard) to stop other people from doing it may also be morally wrong. It is wrong to be rude to your family for no good reason, but it would be even more wrong if the police started arresting people solely for doing that.

> I suppose one can offer up an ethical system that claims to stand independently of biology. If so, I’d like to see it.

You are assuming a materialist philosophy of mind. If a person believes in idealism (as in Berkeley or McTaggart), there is no particular reason why they should expect objective moral truth to be ultimately grounded in biological facts. Scientific theory is famously underdetermined by the evidence, [0] and I think that is true of metaphysical theory as well – there is a lack of empirical evidence to decide between materialism and idealism, and I think the widespread perception that the evidence somehow favours materialism over idealism is mainly due to a failure to take the latter seriously as an intellectual option.

[0] https://plato.stanford.edu/entries/scientific-underdetermina...

> I think, when it comes to questions of discrimination (on the basis of race/gender/etc), it is good that society seeks to prohibit it in public settings (government, the education system, the workplace, public [accommodations], etc), but trying to outlaw it in private is a road to totalitarianism, and that's true even if private discrimination is objectively morally wrong.

Finding the appropriate response is key, in policy, as in individual action. Response to an undesirable behavior need not (and typically should not) be blunt or "zero tolerance". There are a wide range of better responses / interventions.

Policies (whether before-the-incident precautions or after-the-harm responses) can be evaluated both in terms of (a) moral intent and (b) moral outcomes. Ascertaining intent of a collective decision (often requiring some kind of voting or consensus) can be theoretically impossible and often practically impossible.

But when it comes to moral outcomes, there are warning signs that suggest an immoral policy: (i) lack of a targeted impact; (ii) poor benefit / cost ratio; (iii) disproportional response; (iv) high sensitivity (as in "sensitivity analysis") to imprecise or unknowable information; (v) serious unintended consequences; (vi) prioritizing ends over means

Note: I'm using "moral" more broadly than many. Many more people would likely view the above list as indicators of something akin to ineffectiveness, foolishness, imprecision, or misguidedness.