Things are not wrong because the Church says they are wrong. They are wrong because they are wrong, the Church recognizes that fact and speaks to the wrongness of those actions. The wrongness does not change by personal opinion, culture, some “good” that is expected from such wrong behavior, nor even by the culpability of the actor.
So slavery is wrong no matter what the culture, mindset of the owner, or benefit to the economy (say cotton production in the South in the first half of the 19th century).
Same with stealing.
Walking up to a complete stranger and punching them in the nose.
We would all agree that beheading an innocent human being is always wrong.
We don’t have to dig out our Catechism or climb some mountain in Tibet to get an opinion on that.
And yet many (most?) people make all kind of allowances for bad behavior. Would even claim it to be “good” based on the actors’ conscience.
Hear it all the time at abortion mills. “You have your ‘god’, I have mine.” This is a mindset that creates its own god and them shapes him to their needs.
And not just at abortion mills.
When the Church spoke out about the evil of embryonic stem cell human experimentation (aka “research”), the Church didn’t make it wrong. It is always and everywhere wrong to experiment (without the participants’ permission mind you) on an innocent human being with the expressed intent to kill that human being either in the process of the experiment or as the last act of that experiment.
How is it that if we think of that human being as the complete stranger someone walks up to and punches in the nose EVERYONE reading this would agree THAT’S wrong, but if we “walk up to” a complete stranger and without their consent experiment on them and then kill them we say “it’s complicated”?
The ONLY way that happens is to look past that human being (as if they don’t really exist- which of course they do or we wouldn’t “have them” to experiment on in the first place) and focus on some “good” end (cure for cancer, election to political office, etc).
But if it’s wrong, it’s wrong.
Here’s perhaps the ultimate irony: in the research lab, that ostensibly exists to find a cure for cancer through a process that ALWAYS kills its subjects- there’s a good chance they killed the human being who was one day going to find that cure.
Unless of course the moral of the story in “It’s A Wonderful Life” was for George to “have never been born.”?