Ought is a subset of Is
Dragonsphere Report
You cannot derive an ought from an is, and most people who attempt to do so end up looking very stupid. But it turns out you don't need to.
Philosophy reached the correct conclusion that there is no epistemic foundation so firm that it cannot be reasonably doubted. However, while philosophers were busy browbeating everyone with this truth, the program of science was just sort of invented by ignoring this and approaching the domain of the observable + what can be thought about the observable, with moderate humility and a desire for improvement.
Morality is just science + desire. It doesn't need to derive an ought from an is in the same way science doesn't need to refute Cartesian demons. First you figure out what is involved. Then you figure out what everyone wants. Then you practice morality. That's it. There is no need to trace moral foundations back to an irrefutable prime mover or situate them in any broader context.
The big problems impeding the practice of morality are mostly the same as the problems impeding the practice of science: lack of humility, lack of interest in improvement, and refusal to limit reasoning to the observable and what can be thought about the observable.
Why is religious moralism wrong? Because it literally does not know what it is talking about. It doesn't know what the sun and the moon are, let alone what a homosexual or a witch are, so how could it be correct? It is most likely not even incorrect, it is just nonsense.
Why is deontology wrong? It does not know what a moral agent is or seek to measure this physically.
Why is utilitarianism wrong? It does not know what utility is or seek to measure it physically.
There's obviously a lot left to sort out but this is a bare minimum for a starting place.
Thus ends another Dragonsphere Report