The nature of law, broadly speaking, has been conceived of in two ways: through positivism and through naturalism. The former holds that law is the set of decrees lain out by legislators, interpreted by judges, and enforced by armed men. The latter contends that a law is the set of just decrees lain out by legitimate legislators, interpreted correctly by judges, and enforced by armed men. The interminable struggle between the positivist and naturalist ends up as a sort of merely verbal dispute over what we are willing to call “the law,” but contains within it the kernel of a genuine dilemma. Namely, regardless of which position we take, neither seems to allow for the possibility of law as an autonomous field in its own right. Rather, positivism renders law a confused sort of sociology or psychology and naturalism leaves it a wrongheaded sort of moral philosophy. The idea of law qua law cannot be sustained under either interpretation. Given how positivism and naturalism frame the debate over the nature of law, one may find this quite a problem.

The positivist, cynically or pragmatically, recognizes law as a system of power. Law allows speech acts to compel coercion by the state against a population in roughly the same way the rules of basketball allow a referee to disqualify a player from the game. To study law is to study the actual conditions under which legislators write and pass statutes, judges decide cases, and the state punishes violators. Positivists see questions of morality – of how the law ought to be, rather than how it really is – as flights of fancy best left to the philosophers. The study of law becomes a rather restricted subfield of psychology, sociology, and those related social sciences which study a human practice without succumbing to the “bias” of normativity. The project of legal positivism would be complete with the invention of a supercomputer which, when input a history of a judge’s past rulings, political affiliations, what they ate for breakfast, et cetera, would yield a correct prediction about how they would rule on any given case placed in front of them. Under this conception, the study of law could in principle be reduced to the study of physics. The positivist claims to study something called “law,” in other words, but their methodology ultimately undermines the idea that law ought be accorded its own field of study. We might imagine that an alien looking into courthouses or jails through a telescope would end up a legal positivist. That alien, just like the positivist, would be unable to tell us anything we cared about in the study of the law – like whether a case was rightly decided – but could provide myriad statistical generalizations about the propensity of any given judge to pen “Affirmed” or “Denied” after a host of people flap their lips in front of them.

The naturalist, naively or optimistically, recognizes law a system of norms. Law creates the conditions under which society justifiably binds its subjects to a set of rules. To study law is to study the creation and correct interpretation of social rules. Where the positivist sees a realistic approach to law, the naturalist diagnoses a nihilism regarding the very possibility of law; merely using the word “law” and donning nice robes while one utters it does not a law make. While law ultimately concludes in the actual exercise of power, its proper subject matter is the adequacy of the reasons justifying that exercise.

Identifying the nature of law presents an intractable problem for the positivist, who should be happy to pawn this work off to the sociologists and psychologists. The situation seems less dire for the naturalist, who has cordoned off a pasture in the field of norms and set off to graze. But a problem looms wherein law, though not reducible to empirical science, turns out to be political or moral philosophy by another name. If law’s domain is normativity, then lawyers, judges, and legal scholars have thoroughly missed the mark: where they cite case law, they should really be citing Kant. A judge ought decide not by reference to precedent but through rigorous argument to normative legitimacy. The naturalist, in other words, should take law as a subset of moral philosophy and be able to draw a line from any particular legitimate decision back to the fundamental normative principles from which it derives. Any less in the service of state coercion amounts to barbarism.

We are left with the following dilemma: either law is the empirical study of actually-existing legal practice (positivism), in which case law is a subset of descriptive psychology, sociology, or even physics; or else law is the study of the legitimacy of legal practice (naturalism), in which case law is a subset of moral or political philosophy. Both horns yield the conclusion that law has no fundamental nature qua law, and legal scholars and practitioners are systematically confused. Positivists should be running experiments and handing out surveys; naturalists should be deriving judicial decisions from first principles.