Exactly. Catholicism is a set of beliefs that anyone can choose to accept or reject, just like Hinduism or Satanism. The claim that someone who follows Catholic doctrine is not free to reject its principles is just semantics; of course he can reject it, at which point he is no longer following it. I could just as easily say that a libertarian is not "free" to commit murder or theft since that violates the non-aggression principle, and it would be equally meaningless.
You're proving my point.
Funny, from where I'm sitting you're proving my point :)
By the way, if you're an atheist, where do you get this idea that humans have free will?
I'm not an atheist; I'm somewhere between agnostic and Deist.
I think we're arguing around each other, so I'm going to try to nail down exactly what you are trying to prove here.
I'm attempting to show that ethics are non-derivable from empirical facts, and thus the claim of 'objective ethics' is flawed. Please elaborate.