I would suggest that in this case, we’re dealing less with an axiom, and more with an evidentially supported postulate. Because we have plenty of evidence informing us of the horrors that are unleashed, when we don’t have a decent society obeying this principle. That body of evidence, moreover, is about to grow alarmingly, both in scale and with respect to the plumbing of new depths of cruelty and depravity.
Is it objectively true that avoiding such horrors is moral? This seems like subjective consequentialism to me. I agree with the idea, but I can’t claim it is objectively true, unless I am missing something of course, which is quite possible.
Some people find homosexuality horrific, this doesn’t make it immoral, though would claim it to be so.
The closest i can get to moral objectivism is the idea that considering morality is pretty difficult, perhaps impossible, without using harm as some sort of metric.
Anyway I am off out to watch Wales lose another rugby match soon. but I find moral debate quite fascinating.
In response, I would suggest that the suffering of others is observable. Admittedly, regarding the suffering of others as something to be avoided, still has the status of an axiom, but I suspect everyone would agree that avoiding suffering, or alleviating suffering, is something that they wish for themselves. Pretty much everyone of sound mind adopts the same view.
As a corollary, the universality of the wish to avoid suffering on a personal basis can be treated as an observable fact, and from there, we can generalise without loss of rigour, that if we consider actions alleviating or eliminating suffering from ourselves to be ethical, so must actions alleviating or eliminating suffering from others.

the universality of the wish to avoid suffering on a personal basis can be treated as an observable fact, and from there, we can generalise without loss of rigour, that if we consider actions alleviating or eliminating suffering from ourselves to be ethical, so must actions alleviating or eliminating suffering from others.
Brilliant. I’m going to steal that for future use

In response, I would suggest that the suffering of others is observable.
I agree, but that’s not the subjective part, the subjective part is the claim that causing suffering is immoral, so firstly it would have to be relative, that is to say only unnecessary suffering be labelled immoral, but even then moral relativism is evidenced throughout human morality, relative to place, time and culture.
I choose to use harm as a metric in my moral reasoning, but I don’t think it is objectively true that causing harm is wrong, and very sure it is not a moral absolute.

Admittedly, regarding the suffering of others as something to be avoided, still has the status of an axiom, but I suspect everyone would agree that avoiding suffering, or alleviating suffering, is something that they wish for themselves.
I agree, we are following similar lines in our reasoning, but this of course does not mean it is objectively true that because I don’t want to experience something, it is immoral to cause it to happen to others, again this is obviously relative.

Pretty much everyone of sound mind adopts the same view.
A broad or even universal consensus does not make it objectively true though, we are skirting an argumentum ad populum fallacy. The majority of people think a deity exists after all.

As a corollary, the universality of the wish to avoid suffering on a personal basis can be treated as an observable fact,
No I wouldn’t say universal, though this is not relevant to my point, as I am not disputing that it is objectively true that people hold the view that X is immoral / moral, only that the claim it is in fact immoral, is itself not an objectively true claim, unless of course we accept an a priori axiom, for example if we accept a priori the subjective claim that causing unnecessary harm is wrong or immoral, then it becomes objectively true that rape is immoral, but it still rests on a subjective axiom. A very useful one, but nonetheless subjective.

and from there, we can generalise without loss of rigour, that if we consider actions alleviating or eliminating suffering from ourselves to be ethical, so must actions alleviating or eliminating suffering from others.
Again this seems like sound reasoning, and not dissimilar to my own moral rationale, but note the a priori qualifier, which seems subjective to me, or at least requiring an a priori subjective axiom. I can reason that existence will likely be more tolerable for more people if we care about how others are treated, or empathise with them, but the idea a more tolerable existence, even for as many people as possible, is desirable, does not make it objectively true that it is right, and other views wrong. Though it is of course a subjective moral view I share.
Caring about others, or empathising, has to be enough for me, but I don’t see that as in any way supporting moral objectivism. And of course one the strongest arguments against moral objectivism, is that we see moral relativism everywhere, throughout human history. Though of course this, as we have seen from your arguments, does not mean we cannot make moral assertions that are objectively true, once we accept a subjective moral axiom to base them on.
Now whilst metaethical moral relativism abounds, and to a lesser extent so does subjectivism, I have never seen anything close to an example of an objective moral absolute? Not of course definitive evidence that moral objectivism is wrong, but sufficient for me to remain dubious.
I think we agree broadly that life and societal cohesion would become intolerable if we didn’t have laws that broadly reflect the moral ideas of those societies, but these evolve from place to place and over time. This is moral relativism then, not moral objectivism.
Don’t forget about Sadists.
Edit: err … I meant masochists. It’s the masochists who get off on pain, right? I don’t know. I should really brush up on my BDSM internet browsing. Erm.

Don’t forget about Sadists.
Edit: err … I meant masochists.
Yes, one person’s paradise is another’s hell.
This is where I almost have sympathy for moral absolutists. Moral absolutism sweeps aside a whole class of ambiguities that some people find very hard to live with.
The problem is that moral absolutism also isn’t an answer to anything, because the more absolutist you are about morality, the more you want and even need to impose your morality on everyone else. Life becomes a mere power struggle where the strongest get to impose their will on others.
And even THAT is not a statement of objective fact because the state, for example, imposes aspects of society’s commonly shared morality on everyone (try driving down main street at 100 mph and find out what I mean).
I have come to think that morality can only be properly conceived of as the constantly evolving outcome of both formal and informal negotiations between everyone about what the (hopefully civil) society we want to share together looks and acts like. It is not a perfect process that operates by immutable laws. It’s more trial and error.
Now that here in the US we’ve removed most feedback loops from our moral calculus other than what hurts people we don’t like and benefits us and our allies of convenience economically, we’re finding out just how fragile civil society is and how hard we have to fight to achieve AND preserve it.
But make no mistake, what we have is what we negotiated. I get really tired of the people proclaiming “we’re better than this”. Nope. “This” is what we ARE. We can and should aspire to be better, but at present, we obviously aren’t. The proof is in the pudding, as they say.

laws and policies enacted that erode, for instance, freedom from religion
Hopefully, the country will see how awful "what’s this name’ and what’s his name’s leadership is, and policies are. If the US actually survives this, there is a push back to this crap, I can only imagine that things will be much better.

The majority can’t rule without protections for minority groups.
I totally agree. Mostly because I fit into several groups which individually are minorities. And if they are nested within each other, its very minority.
I have no idea what its like to be part of any majority. I keep thinking it would be wonderful and easy. It probably is on many levels, the only down side is that some in the majority have expressed they feel like there isn’t anything special about them, nothing that uniquely stands out. Unless of course they have some amazing skill at something, which is how it should be, ideally.
I feel like I have to work many, many times harder to get and keep a job, and am constantly under a microscope for things that someone in the majority would never understand.

I have no idea what its like to be part of any majority. I keep thinking it would be wonderful and easy.
As a non-disabled middle-class WASP cis hetero man born into a WASP cis hetero and still pretty patriarchal society, my only non-conformity is a mild lean toward Asperger’s which I learned to “mask” early. So for all practical purposes I can tell you it’s so wonderful and easy in many ways that you don’t notice it. It’s like a fish taking water for granted. I can’t know the structural disadvantages and obstacles I don’t know, except second-hand, by reading about them. Even then, it’s easy not to credit them if you don’t live in a very diverse area, like I grew up in (rural Midwest). Back then (1960s & 70s), all the cultural churn and controversy happened in strange far-away places, the coastal cities I and my family never visited.
Consistently throughout life, things just got progressively better and better for me in terms of economic and cultural status, and it’s easy to assume this happens to everyone who’s not a wastrel or something. I’m now upper middle class, debt free, adequate savings for retirement, etc.
Only now, with society collapsing around my ears, am I beginning to become nervous about our long-term viability. Health care going back to the dark ages of re-labeling your medical history as a “pre-existing condition” and declining to cover it, could alone doom me to never retire, and could in various scenarios produce financial ruin or at the very least place us in a dreary nursing home, the kind with the mixed smell of stale piss and bleach, in our final years. Combined with advancing years, I think I am about to experience first-hand what it’s like to not be part of a majority, or at least to be part of a majority that’s well and truly screwed – a society where the only people living anything like “the good life” ARE a minority: the ultra-wealthy.

The problem is that moral absolutism also isn’t an answer to anything, because the more absolutist you are about morality, the more you want and even need to impose your morality on everyone else. Life becomes a mere power struggle where the strongest get to impose their will on others.
I don’t know of a single moral absolute, and whenever they are claimed to exist, the claimant has always failed to offer one, resorting often to either metaethical moral relativism, subjectivism, or emotivism, or even a combination of each of those distinct moral philosophies. It get s a little weird here, as they are mutually exclusive philosophies, yet they share attributes, for example the absence of moral absolutes in both relativism and subjectivism.
I can only say that I must be influenced by moral relativism, and yet I can and do reason past this on occasions, and use moral subjectivism, and I also cannot entirely devolve my morality from my emotional responses, and thus also use moral emotivism, which again I am able to reason past.

And even THAT is not a statement of objective fact because the state, for example, imposes aspects of society’s commonly shared morality on everyone (try driving down main street at 100 mph and find out what I mean).
Indeed, but this is quite ironic, since what we are talking about is moral relativism, cultural or societal influences producing moral assertions, but when we create laws they become objective. Something either is or is not legal, that is a statement of objective fact, but it is as you say not an objective fact that something is, or is not moral.

I have come to think that morality can only be properly conceived of as the constantly evolving outcome of both formal and informal negotiations between everyone about what the (hopefully civil) society we want to share together looks and acts like. It is not a perfect process that operates by immutable laws. It’s more trial and error.
I agree, though I find it personally impossible to talk about morality without using harm, or at least unnecessary harm as some sort of metric. Without it morality becomes meaningless to me. Though again this is a subjective view, even though it appears, and is often use, wrongly in my opinion, as an argument for objective morality.

We can and should aspire to be better, but at present, we obviously aren’t. The proof is in the pudding, as they say.
The majority make decisions in democracies that have far reaching consequences, often based on ignorance, personal prejudices, and even on single issues, and even then often single issues they don’t properly understand. Look at Brexit, huge posters with exaggerated figures of what the UK paid the EU annually, as if we would simply have a windfall that size every year just by leaving, or that immigration would stop or be largely curtailed, neither of which were true, and of course neither of which has happened, predictably.

Don’t forget about Sadists.
Edit: err … I meant masochists. It’s the masochists who get off on pain, right? I don’t know. I should really brush up on my BDSM internet browsing. Erm.
You are conflating pain with suffering, but the whole notion of masochism, is that some pain can be pleasurable. When we talk of suffering in a moral context, we must also I think distinguish between unnecessary and necessary suffering.
Its scary alright. What you said really resonates. Yes, the ideal life that boomers experienced will probably not be available again. I am sure that is alarming to many, and I am sure that is a factor with getting 'what’s his name" elected.
I am continually surprised how anyone thinks that ‘what’s his name’ is going to provide any solution. Also that he’s anything like the ‘average American’. What’s his name has never had to work like most people in the USA. hes only done that as self promotion for photo ops.
I get why people might want a state religion if the majority shares the same beliefs, but I’ve seen how messy that can get. I grew up in a place where one religion dominated everything, from schools to holidays, and it made anyone who didn’t follow it feel kind of excluded or judged. Even if it’s not meant to be oppressive, it can end up sidelining people who believe differently. I think it’s better to keep the state neutral so everyone feels like they belong, no matter what they believe.
Ironically the UK has a state religion, and religiosity has been in fast decline for over half a century. Paradoxically my brother who has Dyslexia and as a result sever Dyspraxia, was slapped as a small child, for not closing his eyes during the lord’s prayer in morning assembly. Next time someone gets sentimental for the 60’s or 70’s, take it with a pinch of salt.
I am for a complete separation of church and state, but then I would be of course.

Ironically the UK has a state religion, and religiosity has been in fast decline for over half a century.
Experience from the nordics regarding this is that a state religion under a responsible regime moderates the church, blunts its power over society, and moderate the public expression of religion. So in that respect I favour a state religion. However, when authoritarians wield religion and want to impose a state religion, it can get ugly very quickly.
All true, and of course even the state religion in the UK, is perhaps a less virulently evangelical version of Christianity than many others, though of course this was not always the case.
It’s also worth pointing out that, many ex Bishops of the CofE are “parachuted” into the House of Lords, I would not be dismayed to see that practice end, and all members of the HoL be elected to that role.