Because there are moral concepts that have appeared in every society, regardless of their contact with each other, there must be a source of morality that is distinct from these individual societies. Although the moral relativist claims that morality is a human invention, morality is not something invented by human beings at all. Instead, there are “absolute” moral concepts that are true, regardless of whether you are living in Manhattan in the year 2004 A.D. or in Egypt in the year 2004 B.C. Noted anthropologist Clyde Kluckhohn has written:
Every culture has a concept of murder, distinguishing this from execution, killing in war and other justifiable homicides. The notions of incest and other regulations upon sexual behavior, the prohibitions on untruth under defined circumstances, of restitution and reciprocity, of mutual obligations between parents and children—these and many other moral concepts are altogether universal.
Clyde Kluckhohn, “Ethical Relativity: Sic et Non,” Journal of Philosophy 52, no. 23 (1955): 672[journal on-line]; available from http://links.jstor.org/sici?sici=0022-362X%2819551110%2952%3A23%3C663%3AERSEN%3E2.0.CO%3B2-K.
So, the moral relativist’s claim that “moralities” differ from culture to culture does not seem to correspond to anthropological research even dating back to 1955. The source of this morality cannot, therefore, be the cultures themselves, but must be something extrinsic, but shared by them all.
Notice, though, that even if the moral relativist could claim that morality is something invented by human beings and is thus definable, then surely one could also make the same sort of claim elsewhere. If there were no absolutes then many disciplines would cease to be relevant. Consider mathematics; where would it be if two plus two stopped being four? What about academia? How can a professor assess a student’s understanding of a topic if there is no absolutely-defined topic to understand? It seems to me that two plus two continues to be four regardless of whether a person believes it or not; a group cannot simply get together and vote to change such a thing regardless of their political power or group size.
The moral relativist might argue that morality is simply a preference decision rather than an absolute truth such as the result of adding two integers. Unfortunately for the moral relativist, it has already been shown above that all cultures have similar moral concepts. If all groups do, in fact, vote to define their version of morality, it certainly is a striking coincidence that they seem to always vote in the same way and for the same issues. Moral concepts are therefore more like mathematics (static) than they are like preferences (dynamic).
Also, the simple act of group agreement does nothing to change the trueness of moral concepts. Since moral truths have commonalities that transcend cultures, we cannot simply agree them away just as we cannot agree for a new result of the mathematical addition of two and two. Suppose the suicidal jumper in our story brought along a friend and they both agreed that gravity (another static concept) no longer had any power over them. If they both leapt from the bridge, I’m certain that the only thing that would change in the story is the addition of another falling body. Just like the gravity that draws their bodies closer and closer to the earth at an increasing rate of speed, the concept that “suicide is wrong” was apparent to both the jumpers and to the on-looking commuters because it is also a static concept and therefore an absolute truth.