I think I now see why Odious and I appeared to be disagreeing (apart from the fact that Odious and Peculiar's blogging endeavours, to say nothing of my own, are animated greatly by the desire to demonstrate that we're such disagreeable men). I believe Odious has been contemplating, in large part, why the law is, while I have been trying to make assertions about the more mundane question of what the law is. Odious is absolutely right that adopting a foolish or unjust rule cannot in any way be justified by saying that it keeps order. Some liberal relativists try to make the claim that the policy underlying all laws is merely arbitrary demarcation of societal boundaries in order to promote the common good; and they cite as examples things like conventions about the direction of traffic lanes. But there is no inherent moral conflict entailed in whether we drive on the right- or left-hand side of the road. To say that no one has any significant interest in the direction of traffic flow independent of whether the direction is regular is not the same as saying that no one has an interest in a legal rule because the rule is an average benefit to society. The latter statement denies the role of the individual, and, in doing so, already postulates the non-relativist assertion that the benefit of the many outweighs the detriment of the few.
Thus, it is is not an argument that society should have a particular law, law as opposed to anything else, or anything at all to say "it keeps order." ("Say what you will about the tenets of national socialism, Dude--at least it's an ethos.") Yet ordering human interactions is what law does--by its nature. Law may even produce social chaos, but its workings would remain as steadfast as ever, awaiting the hand of political reform to gut its mechanisms and replace them with something more sensible. I will even point out from my own experience with judicial decision making that, often as not, when a judge is faced with a question on the frontiers of the law, he will decide what justice requires first, and make his reasons consistent with existing law afterwards. But this process is not, strictly speaking, a legal inquiry. To such an extent as a judicial decision is not based purely on statutory interpretation, legal analogy or some similar method, it is really an extension rather than an application of the law.
To continue the metaphor of biological evolution, the law, as I see it, fills the role of genetic material. Its function is simply to preserve a particular order in the social body. That order may prove to be a bad one, dooming its possessor to extinction, but it is not the basic function of the nucleic acids to change the organization, but to preserve it. I even allow that it may be beneficial, for purposes of adaptation, to have an inherently limited organization (thus, the success of the United States could be attributed to its being a sort of legal cockroach). I also believe quite firmly that it is socially beneficial to have redundant laws of which any can easily come into play should it prove evolutionarily necessary--i.e., federalism is a sort of sexual reproduction, which theory fits pervertedly with the term "laboatories of democracy." ("Igor, bring me the same-sex-marriage law.") Under my metaphor, I suppose it makes relatively little sense to call a law or genes good or bad except to the extent they promote the ultimate health of their possessor. But I am trained not to change the law but to work within it. All my cavilling then, simply arises from a sort of technician's aesthetic--from a pointless fascination with the workings of an object, without any regard to its value. I imagine Odious will argue that it is impossible really to divorce the form of a device from its function, but I can only reply that I largely look at portions of the law so minute and removed from its overall impact that I am forced to hypothesize much of their context. And, though taking a step back from the rules I might see the laws I was studying were mere tools of tyranny and oppression, I would probably still remark, in fatuous admiration, "But they tyrannize and oppress so well."