In my original comment, I had touched on the idea of justice being a strategy (or, as I think of it now, maybe more of a heuristic) for facilitating happiness within a community.

And I guess that's basically how I still see it. At best, it's a means to an end, but not the end in itself.

I could try to reiterate that further, but for now, I'd just like to discuss your example of the "saintly" sufferer.

The Saint and the Baby Buffalo

You said that if a person's suffering on behalf of a community is voluntary, then it is just (i.e. good). But I feel like this claim is assailable in that it begs the question of how free anyone ever is to make their own decisions.

I will grant that each individual person must necessarily believe in their own free will, as a precursor to any other thought or action. But when it comes to our speculation about other people's actions, I think the notion of free will quickly becomes problematic.

Considering, again, the "saint" who suffers on their community's behalf: what if, for example, this saint had in some way been "groomed" (intentionally or unintentionally) for this role since childhood, such that they felt a stronger moral obligation than their peers to suffer on their behalf? Is it still accurate to say that their decision was voluntary, relative to their peers?

What if this saint had previously been a pariah, and saw this burden of suffering as a way to finally gain some respect from their community? Or what if they just had a more active "altruist gene" that made them biologically more likely to act in an unselfish way?

To my mind, whenever you start assuming other people's free will, you're leaving the realm of reality, and entering a realm of pure speculation. Note that this is not necessarily to say that free will can't exist per se, but rather that the act of presuming other people to possess free will is literally never useful in predicting or judging reality.

As a final analogy along these lines: on the African savanna, the young and / or weak members of a herd are the most likely to get caught and eaten by predators. This is generally thought of as simply natural, rather than unjust. And yet, it's hard for me to recognize any meaningful line that can be drawn to accurately distinguish the sacrificial weak buffalo, and the human volunteer saint. The weak buffalo probably didn't choose that fate, and I think neither would any human - even a volunteer - if they really had a choice.

This is all ultimately to say that I don't think a person's ability to "choose" can ever be a useful criterion for determining the relative goodness or badness of a given universe or community. It still, to me, has to be all about whether people are happy or not.

And although I know you don't see much likelihood that this debate will ever be resolved, I guess I just am more "optimistic", so to speak. And I think we might actually be able to make some progress in how we think about human rights and governance, if we are eventually able to fully discount justice-based thinking in favor of happiness-based thinking.