randman writes:
you say you have trouble seeing how science can lead to sexual amorality. Holmes, if I remember, argued based on science, and you admit we are mostly imposing religion on people.
So, in fact, isn't reasonable to claim that science leads to amorality from your perspective at least. I think there are those that argue science indicates monogamous marriage is best for children, people, etc....so maybe science does not.
Morality, amorality, and immorality are terms that make sense only within a specific moral system or model: what is immoral in one system may be trivially amoral in another; a moral obligation in one model is an immoral imposition in another.
The notion of moral relativism is itself prima facie absurd because it suggests it could be otherwise: all moral systems are relative in that they cohere only for those within them. That is why so many of the responses above hinge determinations of sexual morality on the question of consent: if two competent persons act together consensually within a mutually agreed upon moral contract, their actions are moral within that contract. It is as fruitless to judge those actions from within another system as it is to ask the speed of blue. It will not compute.
We disdain the man who "cheats" on his wife
because he has promised not to--they entered into a private moral universe with their marriage vows (if they didn't, and have an open marriage, then "cheats" does not apply). We nearly universally disdain that man because he failed to honor his vow in the most intimate realm; religions proscribe this behavior because a primary function of religion is to reinforce the moral covenants we make together.
One moral bedrock is the familiar, "First, do no harm"--a charge all, not just physicians, might consider. Cited often as evidence of the earliest development of a "moral sense" in children is their response to broken things: toddlers will cry when symmetrical form is broken. To break, to damage, to hurt: these are moral absolutes; what is breaking, what is damaging, what hurts: these are morally relative because they are coherent notions only within a closed system, only between mutual subscribers.
In short, disdain for the philanderer does not impose religious beliefs; he may well not give a fig for our disdain, and even if he does, disdain is an internal state, not an action. To abduct that man into a moral system he has not subscribed to, and then to pursue punitive measures, is an absolutely immoral act. Science can play a part by helping to determine what promotes and what inhibits robust development,what maintains healthful function, etc., but even the question of whether each determination belongs to the morally absolute or the morally relative is outside of science's bounds. Was the masochist tragically hastened to an early grave by the sadist? Or did the masochist trade-off a longer life for a shorter one of fiery intensity?
These are human affairs. Where morality meets muscle, Science and God are largely and equally irrelevant.