You can't do that, because any proof relating to how humans should live would have to start from axioms like "suffering is bad" or "other people are probably re

You can't do that, because any proof relating to how humans should live would have to start from axioms like "suffering is bad" or "other people are probably real rather than imaginary" or "suffering is bad, and other people are real, and it's bad when I suffer, and it's also bad when other people suffer", and you're not going to get everyone to agree on those. The best you can do is to make arguments like "if you accept all the axioms I mentioned above, you should also accept this conclusion".