It's still possible to use decision theory and an utilitarian framework (and/or bounded rationality) to unify whatever two random people's morals happen to be. Sure, in theory people with infinite time on their hands will come to agreement about everything - Aumann's agreement theorem. But even if they don't, it doesn't matter, as they are still going to maximite their utility as best as they every point in time can, with all the complexities involved due to our neurobiology and path-dependence on personal experiences.

Now, that said, ignoring pathological cases (both abstract/hypothetical and real clinical - eg someone just on the verge of suicide) rational agents have instrumental goals, such as survival, gathering resources to be able to survive, keeping warm, but not too warm, etc. And this is where "the fun begins", or the complications. Because there are many possible strategies, just putting them on a predatory-cooperatory spectrum gives a sort of handle on them. (Obviously there are situations where otherwise even the most cooperative-minded person can end up selfish, and vice versa.)

And abstracting all this basically gets you Rawls' Theory of Justice, which says, that since you don't know what situations you can end up in (eg. you don't know if you get cancer in the next year or not), you should think through many situations and determine what would you prefer in them, and then try to find moral norms that are the most satisfiying in the most cases. (Eg. the most fair rules.)

Of course this is extremely handwavy, and naturally - as things in philosophy are rarely - the matter is not settled, but I think there there is a convincing argument to say that sentient minds can find a common moral ground, if they want to.

Diversity with ethical commitments to zero-oppression, avoiding arbitrary enforcement of power.. we do not need uniformity, only universality. To embrace suffering as meaningful is to extend suffering beyond the natural consequences domain into projecting it for power purposes/ control.

Suffering is not necessary, only useful to oppressors. Some suffering from learning is different from that being intentionally utilized for other purposes.

Without universality of commitment to reduction in suffering, there's "managed" suffering of some kind.

I think Nietzsche was a great man and not nearly as judgmental as he conducted himself. But I also believe the classical explanation that he had a problem with his mother and that is the reason why he had such strong expectations towards himself and others.

Nazis abused his writings but he wouldn't have like them of course. His dislike for christian morals is understandable because he saw them as a form of subjugation and contrary to emancipation. I think this grew to an unfortunate amount of hatred later on. He is partially correct as are the morals of Christianity in my opinion.

Well I only invoked the quote as a response to universalism, not necessarily as a reference to Nietzsche’s ideas in general.

But sure, I don’t agree with him on everything, and while I think his diagnosis of Christianity is in many ways correct, it also is flawed in others. Of course we have to differentiate between what Nietzsche actually wrote and what the popular culture notion of his ideas is.

Otherwise, I don’t think I’d agree that his high expectations come from a Freudian read of his childhood. For the most part they are pre-Socratic Ancient Greek cultural values, especially agon, which was a sort of competition.

Weird tendency in modern internet discourse of pseudo psychoanalyzing people in order to discredit them. Instead of say engaging in the discussion, talk about their ideas, etc.

We already have separate countries to contain conflicting cultures. Isn't that enough? They all want to impose their culture on each other but are held apart by the threat of war.