Chris, before you start positing specific scenarios that you regard as "stumpers", I'd be interested in your response to the preceding critique.
How can a given moral principle be "absolute" if we can identify large groups of people over long stretches of time that did not subscribe to same?
Are you arguing for some kind of perfect Platonic morality that has always existed in potential and has only recently emerged in practice?
Are you saying that what you, personally, now regard as moral absolutes take precedence over what they, then, believed? Are you therefore arguing that we (or at least you) have achieved moral progress over our forbears?
If so, how are you able to discern that this progress has achieved its pinnacle and that no further revisions are likely?
What I am saying that is I believe there is a "right" and "wrong" that is outside of us, which means that regardless of the fact the some people do some thing (X)...even a lot of people...at any given point in time...there are things that are simply "wrong"...and some that are simply "right". In short, I do not presume that truth or right and wrong emerge from within us, but exist outside of us and that our beliefs and behaviors (however collective they may be) do not determined what truth, right and wrong are.
I will never be able to prove this to someone whose base presupposition differs (in particular that truth, right and wrong are somehow derived from within us or collectively as society). That position is a rather tenuous one in my view, primarily because, if that is so, then "truth", "right" and "wrong" are never fixed, always changing and one cannot possibly know what they are (beyond a "best guess"), and what to do/not do (right/wrong). Society would be effectively paralized and in constant chaos as the new "truths", "rights" and "wrongs" are constantly emerging and competing with existing "truths", "rights" and "wrongs". One could never be certain whether they are believing/adhering to/doing/not doing the right (there we go again), "truths", "rights" and "wrongs" or the wrong ones (there it is again).
To summarize, I do not assume that truth/right/wrong are determined by what most people are believing/doing/not doing at a particular point in time. I also don't believe that a wrong is made to be "right" because of some otehr wrong that someone else is/may be doing (situational ethics).
Now, I also do not assume that I KNOW what all of the absolute truths/rights/wrongs are (though I think I have a pretty reasonable idea of what a base set of them).
As was mentioned earlier, sometimes we get tripped up with word definitions. That is a fair observation, but when we attempt to stretch, twist, water down definitions itno new things, then I guess we are completely incapable of havign any discussion at all, because...frankly...we don't know what the "true"/"right" meanings of those words are any more.
I think the whole "there is know absolute truth, right, wrong" is a clever, cute, fun, intellectual-sounding thing...but, to me, it is implausible and also seems improbable.