It's desirable to use formal, objective criteria for determining when we do indeed impose actual coercion on people, and those formal objective criteria need a formal structure to be even a little better than, "kill or imprison everyone we don't like on a particular day."he replies
I don't really get this. It's not as if the undesirable things are mysterious, difficult to define, or constantly changing.In present day society what we proscribe (and compel) might not be particularly "mysterious," but they do seem complicated to define (and difficult to learn), especially in edge cases. One has only to look at the text of statutes and case law, which far exceeds the complexity (and sometimes opacity) of even the most sophisticated large-scale information technology documentation.
There is a small handful of socially unacceptable behaviours that are common amongst all people - so common in fact that in most modern legal systems, statutes about them derive from what is called 'common law'.Mr Aversion incorrectly references what appears to be folk etymology regarding Common Law: Common Law is so named not because some small set of principles are common to all people. Common law is, rather, law developed directly through the decision of judges rather than through statute, legislation or royal degree. Common Law is of course written down, and it is the interpretation of what is specifically written down that determines its future application. Its use follows from "the principle that it is unfair to treat similar facts differently on different occasions."
The term originated in 12th century England to distinguish the Court of Common Pleas from the Court of King's Bench, to decide disputes between commoners, i.e. disputes in which the King had no interest. The "commonality" also refers to commonality between English jurisdictions in the 12th and subsequent centuries. Indeed, Common Law is a specifically English cultural construct, and in the West is found predominantly only in England and its former colonies (other European cultures and their former colonies typically use Civil Law, where precedent has much less weight relative to statute). It's worth noting that sharia (Islamic law) uses a general common law structure, but bears little relationship to English Common Law in philosophy, content and application.
Murder, theft, assault, etc. Most people know these things are undesirable and most people don't do them. As I said, I am not convinced that sufficiently many people are deterred by laws, to justify the existence of the cumbersome legal framework.I first have to be a nitpicking pedant: people don't strictly speaking know anything about this subject, they have desires and preferences. We can only know what preferences people actually have. Murder isn't objectively undesirable; people rather do not in fact desire being killed. And murder is unlawful killing; theft is unlawful appropriation of property; assault is unlawful violence. Strictly speaking the terms are meaningless or vacuous without a law.
Nitpicking aside, I think the underlying premise first misses an important point. Mr Aversion appears to imply that a certain small set of principles regarding acceptable and unacceptable behaviors are generally held in common by human beings, and this common knowledge is sufficient for social regulation. This view, however, misses the point in that there's a lot of other stuff, stuff that is not held in common, that people also tend to coerce each other around. One important function of law (perhaps honored more in the breach than the observance) is to rule out what's not common by explicitly stating what is common.
Secondly, the underlying premise actually appears to be false. Our attitudes and preferences about what specifically constitutes "justified" and "unjustified" killing, appropriation of property, violence, etc. varies considerably across cultures and within cultures across time. About the only think we can find in common is that different cultures at different times make some distinctions, but there's no common content of those distinctions.
Your argument would make sense if there was a risk of many people forgetting socially normative behaviour, or for socially normative behaviour to be constantly and radically shifting, but in respect of these basic interactions among humans, the rules are well-established and require no elaboration.The issue is not people "forgetting" socially normative behavior, the issue is that different people's normative conceptions differ. The issue is less that normative behavior is "constantly and radically shifting", but rather that it does shift, and there's value in recording those shifts. (There are also variations in time that do seem worth dampening to some degree.) And the rules are well-established only by the body of recorded law, and apparently do require considerable elaboration.
Fundamentally Mr Aversion attempts here to undermine the pragmatic value of law. Since he makes this attempt, it's worth rebutting, and I think his argument fails. This is not the only argument he makes; his particular argument is not, of course, the only possible (or even only known) specific argument undermining law; and there are other approaches. But the best we can do is consider each case as it comes up, and try as best we can to synthesize all the various cases into a coherent understanding of political philosophy and social psychology.