Addendum

Actually, I should clarify the claim in my last post. I believe that what we call "morally good" and "morally bad" is meaningful only relative to culture, which gives our actions meaning. Sometimes this is taken to mean that those concepts aren't really important. Here's the logic: If "good" and "bad" are meaningful only relative to culture, then they are highly malleable, since culture itself is highly malleable. If they are highly malleable, then they are arbitrary. If they are arbitrary, then they can't be important. That's a possible view, but it's not mine. I certainly do not think that they are unimportant. To be clear, while I do believe that "morally good" and "morally bad" are highly arbitrary, I do not believe that all virtues and vices are likewise arbitrary, and I do not believe that, even if they were, they would be unimportant. I might write more on this in the future.