I don't know what you mean when you ask to whom justification is necessary. That is like asking to whom logic should be rational. It's a meaningless question.

Err... no. You said justify. To justify is to give reason for. You must justify to someone or else you do not justify. It's a very relevant question specific to exactly what you said.

I'm not doubting that different people can have different opinions as to what is moral, I don't know what it means to say that morality is not intersubjective. What would a universe even look like where morality is not intersubjective? I can hardly imagine such a thing.

I never said such a thing. If you want to continue this discussion, please stick to the lines rather than what you imagine lies between them.

Ulitimately people want the best for other people. People who say they don't are either lying or they are irrelevant to the discussion.

Right, so everyone who doesn't align with your arbitrary definition is either disingenuous or irrelevant. ...

A sort of moral dislexia. And what is best for other people is very simple, at least in principle, to know.

The arrogance is amazing.

If you think morality should be something else I don't know what that would be, and why that would be. That is like saying that mathematics should really be cinematics, and litterature should be gastronomy.

What in the hell are you talking about? Did you just imagine a whole other conversation I wasn't privy to?

For most people 'right' is what they did today.

I'm not sure whether that is more begging the question or more circular. Why did they do what they did today if not because they thought it was right?

Because people do not think about what they do until they are forced to. People do not act 'because it is right', why would you think that? People act and then if you ask them why they will rationalise their actions. Why did you eat that sausage, because it was morally correct?

Do you really pressume to tell me that people do not change what tehy think is right based on logic, reason and argument?

Studies have repeatedly shown that logic, evidence and argument are more likely to entrench irrational ideas rather than enlighten.

EDIT: Also, to whom you should justify your actions is clearly part of the justification. You can justify slave ownership by appealing to what is best for the slave owners or what is best for the slaves. Ultimately you should have to justify why what is best for the slave owners is what is morally relevant, or vice versa.

Or you can just be a rich, untouchable slave owner. Why bother justifying myself? To who? In that case justification is irrelevant. I mean do you imagine that logic is somehow the great validator?

Might makes right in practice. Your moral theories sound great, perhaps the books they're written in can be used as body armour.