As I've previously written, I think of law as the weapon of choice for final resolution of disputes in any society that aspires to consider itself civilized. But I haven't yet explained in detail how I think this weapon works, why we should prefer it to guns or swords, and what that means for how it legitimately can and can't be used.
To begin with, a weapon is a tool which is used to diminish the capacities of a target in some way or other. A gun or sword takes away an opponent's choices mainly through blood loss and the incapacity that results, while the law takes away choices by agreement. (Sure, there may be coercion involved through penalties imposed for breaking the law, but law-abiding citizens generally obey the law because they have agreed to do so.)
But why would anyone choose to give up choices? All other things being equal, aren't more options better than fewer? Isn't it irrational to surrender freedoms that one might conceivably some day wish to exercise? (You might think you would never want to murder someone, so why not give up that freedom? But if no one ever had a reason to murder anyone, we wouldn't need a rule against it.)
In fact, surrendering freedoms can sometimes be a very smart move. On his way home from the Trojan War, Odysseus had to sail past the Sirens, whose song invariably overcame the willpower of any who heard them, drawing them to sail onto the rocks where they would be shipwrecked and drowned. Clever Odysseus knew that all he had to do to get past this peril was put wax in his ears and the ears of his crew, so they could not hear the Sirens. But Odysseus wanted to hear the song, too, so he had his crew lash him to the mast and ordered them to ignore him until after they had sailed clear of the danger. And so, by deliberately giving up his freedom to control his ship, Odysseus achieved what no one had ever done before: he heard the Sirens' song and lived to tell about it.
There are lots of non-mythical examples of how surrendering some autonomy can be a smart choice. With respect to the criminal law, we are all better off (more free) if we give up the right to murder each other in exchange for the right not to be murdered, because being murdered extinguishes all freedoms. Perhaps even more significant, though, is the surrender of autonomy through contract law. Seriously, would you do business with me if I said, "I will bring you a bushel of wheat for that piece of silver, but I reserve the right to break all my promises once the silver is in my hand"? The whole point of contract law is to allow us to make (and thus rely on) binding promises. By giving up the ability to break our promises, we gain a greater ability to trade with each other.
I argue, then, that law is something which we ought to obey as rational beings because doing so has the net effect of increasing our practical liberty. We may, on occasion, obey the law out of fear of coercion rather than civic duty, but that need not undermine the legitimacy of the law itself. Odysseus wanted to steer his shop onto the rocks, and was prevented by the brute force of the ropes around him, but his choice to be bound by those ropes in the first place was not invalidated by the fact that he changed his mind under the influence of the Sirens. What matters is that law over all must increase our liberty, regardless of how we may bicker about any particular instance of its constraining our liberty. If law in general makes us freer, then we ought to obey it.
So, the principle I want to articulate here is that properly constituted law represents an investment of liberty: we surrender some of our liberty to the State, which then uses that liberty capital to generate a profit, a surplus of liberty which is then distributed back to us as a liberty dividend. (A regime whose laws do not generate a net gain in liberty is owed no obedience by its citizens. It may impose its will by force, but it cannot claim to be lawful.)
And this is where the moral obligation to obey the law comes from. I need know nothing about your personal moral beliefs and what other moral duties you may feel you have, but can assert that a moral duty to obey the law almost certainly follows from your own value system.
- If freedom itself is a value, this is trivial; you ought to do that which maximizes your freedom, which is what a properly constituted law is meant to do.
- If you do not directly value freedom, you probably value something else for which freedom is at least an instrumental good. That is, if you think being nice to puppies is important, then you should want as much freedom as possible in order increase the likelihood that you will be able to find a way to be nice to puppies in any situation that arises. The same logic applies if you think you ought to sacrifice puppies to Cthulhu, or put things on top of other things, or whatever it is that you may value. Ergo, you ought to obey the law in order to maximize your capacity to advance whatever primary values you do have.
- If you do not value the freedoms that law creates, and prefer the freedoms that it constrains, then and only then do I admit you have no particular internal duty to obey the law. But if you are willing to bear the risk of being murdered or maimed or violated by others, in exchange for your own freedom to murder or assault and violate others, then you can have no principled objection to being imprisoned yourself.