After reading through a recent post by Phaedrus72 about "The liberal tolerance crusade", I was reminded how little understanding people seem to have about what relative morality really means, and why it's better. His argument in both the column and in his comments (ex: "Are you as a liberal, now defending polygamy? Is there nothing to which you won't defend? Seriously.") are a pretty good example of what is wrong not with relative morality, but with absolute morality. Why? Because he's picked an arbitrary standard of morality and declared it to be "right" with absolutely nothing to back it up.
I wrote the article below as part of a FAQ for the Texas A&M Agnostic & Atheist Student Group, of which I used to be a member/officer. I decided to republish it here (with some edits to fit the context) in the hopes of generating a good discussion. I want to be clear that I don't think this is a "liberal" vs. "conservative" issue. Some generalizations can be made about where each side falls on this issue, but those generalizations aren't particularly useful. It's far more important to talk about the morality issue itself and not focus on the partisan politics. That said, I placed this in the politics section because it is a response to a politics post. I hope that's not a mistake.
Absolute vs. Relative Morality
The basic definition of absolute morality is that there is some set of moral rules which are absolute and universal. Relative morality takes the other stance: that morals are not absolute; they depend on the situation.
A problem arises when one tries to define exactly what morals are. After all, by explicitly defining what you believe is moral and immoral, you are deciding for yourself whether someone else is moral or immoral, according to your choices. I could declare that eating broccoli is immoral and that you are immoral if you eat broccoli. You wouldn't have any choice in the matter. This is hardly a useful method of determining morality.
This, in essence, is the problem with the belief in absolute morality. If one believes that there is a global set of absolute morals which everyone must follow, then the immediate questions arise: what are those morals, and how do we know? Since no religion in history has every agreed on a set of absolute morals, and even members of the same religion often disagree as well, we think that the concept of absolute morality is useless. Since anyone could declare that their particular moral beliefs are absolute (and many do), and no one can demonstrate the validity of those claims, the whole thing is arbitrary. Anything goes in that system of belief, for any rule can be declared absolute.
The alternative to absolute morality is relative morality. Unfortunately, this phrase is often mischaracterized and misunderstood. Relative morality does not mean that "anything goes"; it does not mean that any action may be justified; it does not mean that you can't judge anyone for their actions just because you don't know that they're wrong. Rather, relative morality simply takes the stance that no single set of moral rules can possibly account for every situation. Instead, moral decisions should be made rationally, taking into account the consequences of each potential choice.
Relative morality, which I prefer to call rational morality or reason-based morality, can be used to derive a set of basic moral guidelines, such as "don't kill" or "don't steal" or "do unto others as you would have them do unto you". The difference, though, is that each of these morals must have a rational basis. They must, in other words, be shown true in most cases, either logically or perhaps from past experience.
Another important difference is that these morals are general guidelines, but not one-size-fits-all mandates. This is the part of relative morality which bothers many people, but this is usually due to a misunderstanding in what is meant when we say that the rules can be broken. Relative moralists do not arbitrarily choose to break the rules to suit their needs. The rules are broken when the positive effects of breaking the rule outweigh the positive effects of following it. For instance, killing a man may be justified if it would save the lives of other people.
This is what is meant when we say that the morals are not absolute. Morals are tools to help us make decisions which will improve our lives and society. An inflexible mandate would fail to serve that purpose, especially when that mandate is arbitrary and irrational.
Relative morality is often accused of being arbitrary or allowing for anything, but in reality the opposite is true. It is absolute morality which is arbitrary. Sure, absolute moralists have a definite, unchanging set of moral rules, but those unchanging rules change from person to person, religion to religion. One person's mortal sin is another's harmless act. That shows the brutal truth: there is no such thing as absolute morality. All morality is relative. Once we acknowledge this, we can start the real debate about what the rules should be, and that debate can be properly based in reason and fact.