good point, bollinger.
although i am a big fan of nietzsche (in german, of course), i wouldnt have argued the point by his example, though, as its not entirely unproblematic. by "merely" (read quotations very aloud) pointing out that our concepts of good and evil can genealogically traced back to scholastic christian roots, he doesnt refute the point of good and evil itself (its a long time since i read it last, and on my current run through his work, it will be a few days before i reach it again) in particular. thats just like saying (fictional idiotic argument following) because you can trace the christian god via the jewish god to the egypt concept of pharao, who was a man, the existence of god is refuted.
id rather argue with john leslie mackie, and following through his most striking argument, actually with a very phenomenological base:
mackie points out that there coexist many notions of good and evil in different cultures, and that good and evil is not a perceivable quality. we dont have a sense to perceive this quality (avicenna thought of a similar sense, by which one perceives "intention", and hence, the lamb flees the wolf by perception of his intention of eating the lamb). hence, if this quality existed as intrinsic part of the world, theres no way it could be an intrinsic part of our world. so much for objective values...
continuiing on to a rather phenomenological point of view, one could say that there absolutely is such a quality to things, because just look, it is there. you see your hated neighbor and you dont only see the person, but by seeing this person, you also see your judgement of him. however, this quality is part of a world, it is not part of an objective world - the world in phenomenology is inseparable in effect from the subject. there is no subject without world and vice versa. once subject stops, world stops. period.
so, even this way, we dont get rid of good and evil as subject-independent qualities. and that is quite logical, actually. world is there as something a subject has - we dont have access to a world that is independent of the perceiving subject, although we think of the world we have as being the effect of such an objective world. see the kantian point of the imperceivable thing-for-itself and the critique that even the talk of thing-for-itself is hollow talk, not rooted in "the things themselves" but rather a rational principle: causality.
by our very way of being subjects, everything there is is a dependent quality of the subject - there is no possibility for us to have anything else, or anyway else.