You seem to misunderstand most of my beliefs, so I'll try to address that first before I go any further to avoid confusion.

But those "objective" facts would only be about the intuitions of individual minds,

No. Just no. No no no no no no no no no no no no no. NO! NO!

The objective fact is that there is a brain made mostly of neurons and synapses and blood and other kinds of juicy squishyness inside which a certain bundle of those synapses is set in a certain particularly complex (as far as we know) arrangement, and when something is sent as input to that bundle of synapses of the form "Kill this child?", the bundle sends queries to other bundles: "Benefits?" "People who die if child lives?" "Hungry?" "Have we had sex recently?" "Is the child real?" etc.

Then, an output is produced, "KILLING CHILD IS WRONG" or "KILLING CHILD IS OKAY HERE".

Human consciousnesses, the "you" that is you and that wouldn't randomly decide to start masturbating in public while sleepwalking (you don't want to be the guy whom that happened to, seriously), doesn't have access to the whole thing that the bundle of synapses called "morality" inside the brain actually does. It only has output, and sometimes glimpses of some of the queries that the bundle sent to other bundles.

In other words, intuitions.

What I refer to as an "objective fact", the "objective" morality of that individual, is the entire sum of the process, the entire bundle + reviewing by conscious mind on each individual process + what the conscious mind would want to fix in order to be even more moral by the morals of the same bundle of synapses (i.e. self-reflectivity). The exact "objective morality" of each human is a complicated thing that I'm not even sure I grasp entirely and can describe adequately, but I'm quite certain that it is not limited to intuitions and that those intuitions are not entirely accurate.

Same problem. A thinks it is moral to kill B, B thinks it is not moral to be killed by A. Where is the objective moral fact there? (...)

The "objective moral fact" (to use your words), in this toy problem, is that IF AND ONLY IF A is correct when A thinks it is moral for A's morality system to kill B, and B is correct when B thinks it is moral for B's system to not be killed by A, then and only then it is moral for A to kill B and it is moral for B to not be killed by A. There is no contradictions, the universe is just fucked up and lets shit like this happen.

(...) Objective moral facts (or at least intersubjective ones) need to resolve conflicts between individuals. You have offered nothing that can do that.. Morality cannot just be a case of what an individual should do, because indiviuals interact.

What? No. First, that's called ethics, the thing about how individuals should interact. The reason ethics is hard is because each individual has a slightly different morality, but the reason it's feasible at all is because most humans are fairly similar even in this.

Most humans, when faced with the toy problem of saving ten young lives versus three old ones, will save the ten young. Most humans, when they see a child get horribly mutilated or have their flesh melt off of their bones, will be revolted and feel that this is many kinds of Very Wrong.

For most humans, if they have a small something they value a little bit, but that if they give it up temporarily they know they can make another human's morality become much much better, while if they stick to keeping their small something to themselves that human will feel horribly wronged, will give up that little bit for the benefit of the other human's morality.

This seems to indicate that most humans have a component, somewhere in this bundle of synapses, that tries to estimate what the other bundles of synapses in other brains are doing, so as to not upset them too much. This is also part of what helps ethics be feasible at all.

Then morlaity is not so objective that it is graven into the very fabric of the universe. The problem remains that what you have presented is too subjective to do anything useful. By all means present a theory of human morality that is indexed to humans, but let it regulate interactions between humans.

I don't even understand what you're getting at. I'm not trying to come up with a system of norms that tells everyone what they should do to interact with other humans. How is it too subjective to be useful?

I've merely presented my current conclusions, the current highest-probability results of computing together all the evidence available to me. These are guesses and tentative assessments of reality, an attempt at approximating and describing what actually goes on out there in human brains that gives rise to humans talking about morality and not wanting to coat children with burning napalm. (sorry if this strikes political chords, I can't think of a better example of something public-knowledge that the vast majority of humans who learned about it described as clearly wrong)

As for being "too subjective to do anything useful"... what? If I tell you that two cars have different engines, so you can't use the exact same mathematical formula for calculating their velocity and traveled distance as they accelerate, is this useless subjective information? Because what I'm saying is that humans have different engines in terms of morality, and while like the car engines they have major similarities in the logical principles involved and how they operate, there are key differences that must be taken into consideration to produce any useful discussion about the velocities and positions of each car.

That is hard to inpterpret. Why should opinions be what is "objectively moral"? You might mean there is nothing more to morality than people's jugements about what is good or bad, but that is not an objective feature of the universe, it is mind projection. That the neural mechanisms involved are objective does not make what is projected by them objective. If objective neural activity makes me dream of unicorns, unicorns are not thereby objective.

Apologies for being unclear. Opinions are not what is objectively moral, I was saying that the bundle of synapses I described above is both the main part of what is objectively moral (well, the algorithms implemented by the synapses anyway), and what comes out of the bundle of synapses is also what generates the opinions. They are correlated, but not perfectly so, let alone equivalent/equal.

So more often than not, one's opinion that it is wrong to suddenly start killing and pillaging everyone in the nearest city is a correct assessment about their own morality. On average, most clear-cut moral judgments will be fairly accurate, because they come out of the same algorithms in different manners.

The latter two sentences of this last quote seem to aptly rephrase exactly what I was trying to say. The are objective algorithms and mechanisms in the bundles of nerves, but just because the conscious mind is getting a rough idea of what it thinks they might be doing after having a "KILLING CHILD IS WRONG" output a hundred times, the output still doesn't have access to the whole thing, and even if it did there are things one would want to correct in order to avoid errors due to bias.

I can't really be more precise or confident in exactly what is morality in a human's brain, because I haven't won five nobels in breakthrough neurobiology, philosophy, peace, ethics and psychology. I think that's about the minimum award that would go to someone who had entirely solved and located exactly everything that makes humans moral and exactly how it works.

"We" individually, or "we" collectively? That is a very important point to skate over.

The ambiguity is appropriate, though unintentional. The first response is "we" individually, but to some extent there are many things that all humans find moral, and many more things that most humans find moral. Again the example of napalm-flavored youngsters.

So each of us has a separate algorithm, but if you were to examine them all individually, you could probably (with enough effort and smarts) come up with an algorithm that finds moral only what all humans find moral, or finds moral whatever at least 60% of humans find moral, or some other filtering or approximation.

To example you, "2x - 6" will return a positive number as long as x > 3 (let's not count zero). Similarly, "3x - 3" will return positive as long as x > 1. If positive numbers represent a "This is moral and good" output, then clearly they're not the same morality. However, "x > 3" will guarantee a space of solutions that both moralities find moral and favorable.

(two-part comment, see above or below for the rest)