[chezlaw]

As I've said I doubt the existence of AM but here's a thought.

'I don't want to cause needless suffering'

is a moral fact about me. The argument against AM usually takes the form 'but what if someone wants to cause needless suffering, then it would be ok' but maybe thats the wrong way to think about it.

Could any rational person want to cause needless suffering?

It may be that to understand the concept of suffering in others requires a level of empathy which makes you not want to cause it without some other need.

Then an absolute moral law would be.

'It is immoral to cause needless suffering.'

chez