I don't think we disagree on the fundamentals here:

"an Is that entails what one Ought Not to do." is what you noted, which of course logically leaves us with 'what should be' vs 'what should not be'.

I agree that unnecessary suffering 'should not be', my point is that this can only be objectively true if good is objectively what 'should be'. The moral fundamental that 'existence is better than non-existence' is required for us to at any point claim 'X should exist". Because all questions of morality chain down to this fundamental question.

Why should suffering not exist? Because it overall lowers the quality of a living being's life. But why should there be a living being at all? Because its an increased concentration and complexity of existence that produces far outcomes than the material alone. Why should there exist anything at all? Because existence is better than non-existence.

The point of a fundamental is you can get to a point upon which you can build from. It also acts as a floor when working backwards. There comes a point where we have an answer, and there are no more questions. The answer is the reason, the fundamental that logically must be.

It sounds like you're asking what normativity most fundamentally is? And you sound like a structuralist. You're looking for a answer that explains all the disparate pieces, like the two-dimensional people building a theory from watching a spoon pass through their plane. All they see is a dot that turns into a line, and back to a dot. What is it?

I read a book by a structuralist who focused on gnostic myths. The typical myth goes like this:

In heaven, all was silent because nothing is undone in heaven. Then, out of the silence came the first question: what is this?. God turned to the questioner and said: "Silence yourself. There are no unanswered questions in heaven." The questioner understood and complied, but something about this event caused a part of the questioner to fall out of heaven, and this part is known as Sophia. In time, Sophia gave birth to a blind god named Samael. Samael's body is our universe, but everything that happened in Samael took place in blindness. There was murder and violence, but it didn't mean anything. It was like a play with no audience.

Sophia felt sad when she looked at her son, who couldn't see her. So she whispered into his ear and what she said pervaded his body and coalesced in humans. Humans awoke and began to see their world for the first time. They felt guilt and shame. They had become their own audience. And they turned to see beyond their world, to heaven, where all questions are answered.

For a structuralist, a story like this could be about something that is always happening in the present, maybe below the surface. — frank

Not structuralism. Post structuralism, the denial that language really has any rigorous commonality among those in a language group. No, the idea here goes beyond this discussion. The issue is about the essence of ethics, what is ethics such that were there an absence of this, ethics would cease to exist, like logic vanishing without tautology and contradiction. I am saying that the dominant position that is the denial of objectivity in ethical matters is wrong, and the evidence for this in, if you will, in the fabric of existence: suffering and delight. What ARE these? No less than the explicit manifestation of, say, having your teeth pulled without anesthetic, or being in love. Max Scheler refers to this as non formal value and ethics (arguing against Kant's ethical formalism). But no more than this? This is a hard question. To say what happiness is IN a context of relations, uses and purposes is one things, but then, what about "out" of these contextual indices? This outside is a matter of being outside of language. Suffering lies outside of language, as does the beauty of Ravel's Mother Goose Suite. We do face interpretative contexts everywhere in our entanglements with the world, but these interpretations are what suffering IS.Suffering IS what it is in al its manifestness, and this is acontextual.

Well, objection works with the early analytic notion of the "absolute ' which was bound up with their conception of "abstract objects " and the notion that "objectivity approaches truth at the limit." It comes out of a certain view of naturalism where the perspective of consciousness is a sort of barrier to be overcome, the much maligned but often reproduced "view from nowhere." However, such a consideration of the "absolute" has probably had a longer life as a punching bag for continentals than it did as a position that was actually embraced by large numbers of philosophers. — Count Timothy von Icarus

"View from Nowhere" is an attempt to slip past the glaringly obvious world of actualities we live in. But nowhere means nowhere IN the potentiality of possiblities that arise with a particular ontotheology, where this term is bound to finitude, like talking about Christian metaphysics and a list of superlatives that belong to God, the whole affair extracted from the familiar and its habits of thought of a particular time and place. "Nowhere" is being itself. "Absolute" is a categorical attempt to speak this, which fails, to put it in Kant's terms, because it is a concept without intuitions, empty. The real question that haunts this inquiry inspired by Hamlet's claim in the OP is, is there really no intuition beyond the (merely) empirical? If you break a leg, does the excruciating pain not deliver an "intuition" that stands up to the vacuity of the locution "view from nowhere"? This question issues from outside the historical matrix that informs language's "games".

I would think though that to be properly absolute, in the sense the term is normally used outside that context, is not to be "a reality as set over and against (and outside) all appearances," but rather to include all of reality and appearance. Appearances are really appearances, and so they cannot fall outside the absolute. Hegel's Absolute does not exclude any of its "moments" for instance. — Count Timothy von Icarus

Perhaps you intend it this way: like Kant's noumena, what is it that is NOT noumenal? To say the phenomenon is not noumenal means to draw a line between the two, but how is a line to be drawn if the noumenal is impossible to conceive? It is not that the noumenal is some impossibly distant ground for all things; rather, all things are the ground and metaphysics is discovered IN phenomenality: in the foundational indeterminacy of categorical thinking and the presence of empirical objects. It is all a unity, yet beyond unity.

This is relevant as far as grounding the human good in human nature goes. Sometimes, one sees the claim that: “there is no such thing as human nature.” Prima facie, such a claim cannot be anything but farcical if it is not walked back with so many caveats so as to simply reintroduce the idea of a nature in some modified form. It is clear that man is a certain sort of thing. We do not expect that our children might some day soon spin themselves into cocoons and emerge weeks later with wings, because this is not the sort of thing man does. We know that we will fall if we leap off a precipice, and we understand that we are at no risk of floating away into the sky when we step outdoors. Things possess stable natures; what they are determines how they interact with everything else. Beans do not sprout by being watered in kerosene and being set ablaze, nor can cats live on a diet of rocks. Attempts to wholly remove any notion of “human nature” invariably get walked back with notions like "facticity," “modes of being,” etc. (Generally, the original idea of a "nature" is presented as a sort of straw man in these cases). — Count Timothy von Icarus

Unless the question as to human nature goes to language itself. Then all things lose their nature, their essence. Sure, we know that beans do not sprout watered with kerosene, but kerosene: what is this apart from the repeated results of a scientific determination, where repeatable results define what kerosene IS. Light a match to kerosene and it burns, without fail under "normal conditions". But IS kerosene reducible to this IS and others like it that congeal into habits of perceptual anticipation? But then, who cares? The factual dimensions of kerosene are absent of meaning apart from the basic features of language, the logic, irony, metaphor, imagery, pragmatics (especially), and so on, and kerosene can be contextualized and recontextualized into eternity, and when these are put to rest, the residuum is nothing, mere being as such...that is until the value dimension is recognized. Now being as such is "life" as Michel Henry talks about it. Meaning outside conceptual open endedness.

The original idea of a nature as a strawman, referring to something as absurd as a real subject, like a soul, absurd because unobservable.

Not structuralism. — Constance

Why not structuralism? It's a candidate for answering what ethics is.

his is a hard question. To say what happiness is IN a context of relations, uses and purposes is one things, but then, what about "out" of these contextual indices? — Constance

The ancient Persian answer is that goodness is the direction we're reaching out toward. Evil is what we're pushing away from, so a good person is in motion, or progressing. In this view, it doesn't matter what your present condition is, if you're progressing, you're good. If you're stationary, you're evil.

The ancient Jewish answer is that goodness is clear for all to see in your health and well-being because obviously God is blessing you. A similar outlook is Roman stoicism, which aligns goodness with Nature. It's in a tree's nature to grow toward the light, if it fails to do this, it becomes sick. Sickness and evil are basically the same thing: a failure to abide by your nature. I like the the Roman view because it's efficient.

If you notice, both these views allow flexibility in what actually counts as good. We may discover through experience what really constitutes progress or health. On the other hand, they conflict in whether goodness shows up on the surface, or if it can be hidden. Our present worldview is a fusion of ancient views.

Good = actions that prevent or reduce suffering and promote well-being for sentient beings.
Evil = deliberate actions that cause unnecessary suffering or destroy the capacity for well-being in sentient beings. — Truth Seeker

Yes, I think you are closing in. But there does remain the final question: what is there that is bad about suffering? You may, as I do, hold that this is self evident, though this gets lost in our entangled affairs, where competing goods and bads struggle. But the question is now momentous, not mundane: Suffering is now not a convention of the language and culture that talks about it, talk that leads to variability because suffering is inevitably caught up in uses and purposes. Suffering is the bare manifestation of that terrible pain in your ankle, and this, if you can stand it, transcends the finitude that language that would hold it down, keep it familiar, contained in reduction to the ordinary. But suffering is not ordinary, not an institution. It is that original that institutions of ethics have their foundation in.

The above is the full argument so you can understand where I'm coming from. — Philosophim

Her is where the argument has trouble:

Definitions:
Good - what should be
Existence - what is
Morality - a method of evaluating what is good

This puts existence under the critical determinations of ethics, a call for an "ethical ontology" under which all things abide. Now, someone like Mackie (see his Ethics: Inventing Right and Wrong) will call this "queer"--for what kind of ontology IS this to rule over all existence? Only God has had this impossible place in the world, and God is conceived in ancient terrified mentalities. What is the basis for this assumption of a "God" (notwithstanding the absence of the term in your argument. The Godlike "queerness" holds.

Not that I think Mackie is right. But this above needs to addressed.