Subjective Morality?

[vulcanlogician]

But in all cases, if nobody ever cared about rape, then there never would have been anything said about it.  Furthermore, since sexuality long predates humanity, then I'd definitely say that feelings about sexuality must predate our ability to verbalize or to hold rational views about it. In other words, I'm pretty sure whether the chicken came before the egg.

I want to to isolate this portion of your argument to show how wrong-headed this type of argument is. We can return to your other points later. But (if I accomplish anything) I'd like to convince you to stop taking this approach to criticizing moral objectivism.

Let us not consider rape "since sexuality long predates humanity... feelings about sexuality must predate our ability to verbalize or to hold rational views about it." Let's consider something else.

Let's say in that in the far future, mankind sends probes to Alpha Centauri and discovers a long-dead alien civilization. We then send more vessels to gather some of the aliens' technology and return it to Earth. Among the alien tech, we find some sort of helmet that allows its wearer to read the thoughts of another person and also causes the target of the thought-reading to feel intense pleasure during the process. When scientists discover this ability of the helmet, they name the phenomenon "grok-o-fecting." Humanity soon learns how to reproduce the alien tech and Grok-o-fecting becomes a popular pastime on the planet Earth.

The thing is, it is later found that grok-o-fecting leads to long term nervous system damage and also interferes with the target's ability to feel pleasure or pain due to normal external stimuli.

So some ethicist in the future makes a moral judgement about grok-o-fecting. She says "Grok-o-fecting is morally wrong."

Surely a counterargument cannot be "since grok-o-fecting long predates humanity... feelings about grok-o-fecting must predate our ability to verbalize or to hold rational views about it." Because this simply isn't true. Furthermore, it has no bearing at all on the issue of whether the ethicist's judgement is an objective matter or a matter of opinion. It is a red herring that doesn't belong in the argument at all.

I hope my weird little sci fi yarn demonstrates how misguided it is to mention the evolutionary origins of feelings concerning a given action or behavior when discussing meta-ethics.

****

In response to your other comment about "if nobody cared about rape, nothing would ever be said about it." Immanuel Kant had an odd answer to this thought experiment:

You answer the doorbell late at night. Upon opening your front door, you see a man covered in blood, holding an axe. He asks where your child's bedroom is, stating that he intends to chop your child up in to little bits.

Kant says that it would be wrong to lie to him about the location of your child's bedroom. (He says that remaining silent would be the most ethical course of action.)

Let's think about this for a moment. If you did lie to this person nobody would CARE. If this happened IRL, and you told the axe murderer your child was asleep in the local police station where he was thereafter arrested, nobody would say, "Hey man. You lied to that guy." In short, nobody would care at all. But even so, Kant still had something to say about it.