My last post was a question (now edited). You were tacitly assuming that being able to predict is what matters, that non predictive theories can be disregarded. I was questioning that being able to predict matters more than morality (in fact, I was doubting that anything does). I think the does-it-predict test is flawed in that sense.

I also think the other tacit assumption, that morality is non predictive is false. If you act on your morality, it will predict what you observations...whether they are eventually of a death row cell, or a the receipt of a nobel peace prize, for instance. If you don't act on it, why have it? Morality is connected to action, treating it as a theory whose job it is to predict the experiences of a passive observer is a category error.

The problem I have with subjective morality is that I can't see how it differs from no morality:

If subjective morality is true, everyone does as they see fit and there is no ultimate right or wrong to any of it.

If error theory is true, everyone does as they see fit and there is no ultimate right or wrong to any of it.

That, if correct, only goes as far as establishing that morality is either objective or non existent.

You wonder what would change given the truth/falsity of objective morality. What would change is the truth and falsity (and rationality and irrationality) of things that are logically linked to it. You can either be in jail at time T or not; that's objective. If objective punishments and rewards can't be objectively justifiied, there is a certain amount of irrationality in the world. So what objective morality would change is that certain ideas and attitudes, and actions leading from them , would make sense the world would be a more rational place.