Visible applies only to visible light or bodies it reflects off of. Something does not have to be visible in order to detect it with more sophisticated instrumentation.
Humans can feel empathy for rocks when they want to. If empathy were a god-given innate behavior, not taught or learned, then humans would only be able to feel empathy for other humans, not other creatures, and in the absence of both, inanimate objects. And there wouldn't be so much variation in the world's religious beliefs. If a religion can thrive where death is celebrated and human sacrifice is the ultimate gift, then empathy for other humans and a concern for their well-being is NOT an innate quality.
Applying the same logic to our original argument, if homosexuality were innately "wrong" then every single culture, religion, and government would agree on it's detrimental quality and would universally condemn it. There would be nowhere it was considered commonplace or even tolerable. That mindset is what DROVE the inquisition. "There is good and bad, and they are always distinguishable, and anyone bad is TOTALLY bad and needs to be put to death for the betterment of out christian society! Because everything but christianity is wrong and bad!"
