A: Homosexuality is morally permissible.
!A: Homosexuality is morally impermissible.
B: Heterosexuality is morally permissible.
!B: Heterosexuality is morally impermissible.
(A or !A) is compatible with (B or !B) however A as a normative claim is not compatible with !A as a normative claim. [Law of the excluded middle]
Without knowing the criteria for true morality, we cannot say whether a difference in norms between different societies is (1) evidence of error by at least one society, or (2) a trivial difference like the different colors of the interior walls of houses. The criteria I have specified (functionality and sustainability) allow me to pass meta-ethical judgment, but you don't accept my criteria.
We can (assuming logic is true) know that less than both Normative claims (A and !A) are true. I was criticizing using the societal norm of holding one of these Normative claims to draw conclusions about the True Moral Code because that norm's correlation fluctuates with the society.
The claim: Functionality and Sustainability is a Normative Ethical claim.
We started by discussing my Normative claim that Free Will was necessary for Immoral action from a Meta Ethical position.
We continued by discussing your Normative claim from Meta Ethical and Normative Ethics and
Applied Ethics perspectives.
However the claim that it is relevant to questions of Ought is a normative claim. Built in potential does not inherently mean relevant without assuming a prior normative claim.
I say that it is an empirical issue. Do people with empathy behave more morally than people without empathy? Do people behave more morally when their empathy is evoked than when their antipathy is evoked?
Much of human behavior can be explained as a joint function of motivation and ability. Our discussion of moral competence touches on one aspect of the ability to make moral decisions. Empathy has a role in the motivation of morality. When news of a child in danger is broadcast, people all around the world are emotionally affected, hope for the best, and support the efforts made to save the child. A catastrophe elicits worldwide charitable donations for relief aid. Something that makes people care about those whom they have never met, and in many cases are very different, is a powerful force.
Perhaps you are using Empathy to mean something different?
Empathy and Antipathy are not related like that.
Antipathy is dislike for something or somebody, the opposite of sympathy. [Wiki]
Empathy is the capacity to recognize and, to some extent, share feelings (such as sadness or happiness) that are being experienced by another sentient or semi-sentient being. [Wiki]
It is understanding based not motivation based.
Empathy permits greater acts of Morality or Immorality because it increases understanding of the world.