Diametrically opposed to the theological theories are various forms of moral relativism. Moral relativism says that there are no universal moral principles. Morality is a matter of customs or opinions or habits or emotions. There is a range of opinions here: Relativism is sometimes considered a kind of moral skepticism, which would say that we never truly know what is good or bad. Others see it as a moral nihilism, which says that there simply is no such thing as good and bad, that those words are just misleading labels for other, simpler, things.

One brand of relativism is called conventionalism. This says that what we call morality is really a matter of our cultural or social norms. What our traditions say is right and wrong (for whatever reason) is right and wrong. Often, along with that, comes the idea that cultures and societies should not interfere with each other ("when in Rome..."), but that is not necessary.

Another brand is called prescriptivism (or imperativism), which looks at morality more in terms of power within a society. What we call right and wrong are essentially prescriptions as to what we want others to do, which we then enforce with the powers at our command. So call theft “bad” so that we have a justification to put people who take our stuff in jail!

Of course it is inevitable that we come across other societies who believe that what they want is their “right” regardless of what we want. Or we come across situations where there are two subcultures or societal groups whose moral beliefs come into conflict. One of the difficulties of conventionalism is defining what constitutes a society or culture and what, if any, are the rules of interaction between or among them.

One “solution” is to reduce the culture or society to a culture or society of one -- that is, the individual. This is called subjectivism. Here, each person has his or her own morality. It may be a matter of individual beliefs, or a matter of habit, but each person makes their own choices. That does take care of the problem of what is a culture, but it only makes the problem of rules of interaction worse!

Another brand of relativism goes even further: emotivism says that what we call good and bad are just labels for certain emotional responses we have to certain acts. If the idea of eating puppies makes you sick, you call it bad. If it makes you salivate, you call it good. If having sex with teenagers makes your day, you call it good. If it gets you all upset, you call it bad.

Among my students, I find that freshmen often bring with them their home town religious beliefs. They tend to like the divine command theory, with a few absolutists thrown in for spice. But by the time they are juniors, most of them have become relativists. The home town crowd often blames this change on professors, but it is more a matter of exposure to the pluralistic mini-society of college.

The freshmen see that there are many people who disagree about one detail or another of their childhood moral codes, yet appear to be decent people, or at least have not been struck down by thunderbolts. So, being decent folk, they begin to emphasize tolerance for the variety of moralities they see, and relativism seems to be the best format for this tolerance. For example, if you were raised to believe that homosexuality is wrong, yet you find many people who believe that it is okay (and some who think it’s the only thing to be), you may develop a live-and-let-live attitude that says “to each his own.”

But not everything is as innocuous as sexual preferences. There are people whose moral codes say we must sacrifice chickens to the Gods, or we must convert the non-believers, or we must burn witches at the stake, or we must destroy the infidel.... What do we do then with our kind tolerance? Let them be because “to each his own?” What if we had done that when Adolf Hitler had his time at bat? Or what if Jeffrey Daumer’s neighbors decided that, well, if he wants to kill and eat his lovers, what business is it of ours?

A sophisticated relativist would respond, however, by pointing out that this tolerance business really has no place in a relativistic moral theory -- that tolerance is itself a moral value that one may or may not adhere to! So, if it is Hitler’s moral code to exterminate innocent people and invade neighboring countries, it’s our moral code to make him stop it! No logical problems here.

As you can see, though, relativism does take a risk. Relativism can become moral nihilism in the same way that divine command can become absolutism. Nevertheless, relativism is the moral theory followed by the majority of people in the hard sciences, including the more experimental, physiological side of psychology.