Arguing with Sillyheads

[Zav]

I'm having a debate with someone on YouTube (yes, yes, I know). It is the strangest argument I've had in a while, because it evolved from whether science was evil, to Atheism vs. religion, to Veganism vs. Omnivorism, to saving ecosystems vs. saving species, and finally to the existence or not of a universal human ethos. I've easily won the other mini-arguments, but on this one I'm stuck. I argue that because no moral has been held by every person of every society for all time, a universal morality cannot exist (essentially the argument against human nature) and each person's ethos is subjective and thus not fit to constitute an objective argument. This person's argument boils down to the ideas that some morals are universal, like rape and murder are bad, and that defining things into subjectivity and objectivity is somehow an invalid way to categorize things. I've reworded my side of the argument twice to try to break this person's circular logic to no avail. It's like arguing with a bible-thumper (except with Voodoo).
I don't back down from arguments, so what I want to do is to try committing argumentum verbosium. Does anyone have any particularly difficult essays criticizing moralism (should I call it moral absolutism?) that I can rip off? If not, how do you go about combating circular logic in general?

[Blanquist]

I think you're wasting your time but here's what you're looking for

http://www.marxists.org/archive/trotsky/1938/morals/morals.htm

[Zav]

I think you're wasting your time but here's what you're looking for

http://www.marxists.org/archive/trotsky/1938/morals/morals.htm
I know, but it's fun. Thanks for the link. :)

[Revolution starts with U]

There are murderers and rapists who didn't believe themselves to be. Argument won, game over.

[Ocean Seal]

I'm having a debate with someone on YouTube (yes, yes, I know). It is the strangest argument I've had in a while, because it evolved from whether science was evil, to Atheism vs. religion, to Veganism vs. Omnivorism, to saving ecosystems vs. saving species, and finally to the existence or not of a universal human ethos. I've easily won the other mini-arguments, but on this one I'm stuck. I argue that because no moral has been held by every person of every society for all time, a universal morality cannot exist (essentially the argument against human nature) and each person's ethos is subjective and thus not fit to constitute an objective argument. This person's argument boils down to the ideas that some morals are universal, like rape and murder are bad, and that defining things into subjectivity and objectivity is somehow an invalid way to categorize things. I've reworded my side of the argument twice to try to break this person's circular logic to no avail. It's like arguing with a bible-thumper (except with Voodoo).
I don't back down from arguments, so what I want to do is to try committing argumentum verbosium. Does anyone have any particularly difficult essays criticizing moralism (should I call it moral absolutism?) that I can rip off? If not, how do you go about combating circular logic in general?
Stop caring the existence of a universal morality is not something that you can successfully prove or disprove.