Legal positivism was the "ruling paradigm" prior to the Second World War,
and remained strong in the Soviet Union and Mao's China. Legal scholars in the post-Soviet world seem generally unaware that this supposedly "scientific" conception of law was rejected in the West half a century ago, especially in the United States. This rejection had much to do with the evident incapacity of "German legal science" — essentially, legal positivism — to provide any corrective to Nazi, Communist, and similar totalitarian ideologies and practices. See T
he Theory of State and Law. Popularized by Hans Kelsen, legal positivism defined law as essentially the "authoritative command" of that power which has the capacity to force compliance. The lawyer's job was to be a scientist who focused on what the law "is" without reference to what it ought to be. In some fundamental sense, legal positivism showed little interest in how law came to be that "is"; legal positivism did not focus on how law and civilization coevolve. See
Note on Coevolution. See
Evolution and Coevolution.
The only "ought" of legal positivism was that the law's commands must be consistent and knowable. Interestingly, places like Hitler's Germany and Stalin's USSR claimed adherence to legal positivism (to the extent that their shifting intellectual grounds claimed adherence to any jurisprudence whatsoever) yet much of their "law" was secret and — especially in the USSR — contradictory. The resulting fact that nobody could "follow the law" served the State inasmuch as everyone was subject to "legitimate arrest" (in a manner of speaking) for violations of something somewhere called "law"; this condition persists throughout most of the former Soviet Union.
Legal positivism is generally contrasted with two other schools of jurisprudence:
The older, "natural law", has long taught that law must have a moral and rational component in order to deserve that name. In the late 1930s, Professor Lon L. Fuller (1902-1978) asserted that "natural law" thinking supplies a necessary corrective to legal positivism. For Fuller, the law that "is" must be grounded in fundamentals reflecting the "ought" — else the law becomes mere "description" of the commands of those who monopolize coercive power rather than prescription and proscription rooted in fundamental ethical and intellectual values. Fuller's general thesis is summarized in my essay,
Rule of Law: Ten Principles Governing Law and Law-Making. I supplement Fuller's "nine principles" with an important one that was central to his thinking yet is not "listed" in his seminal book on this subject, The Morality of Law (1964-1969). That tenth principle, the first in my list, is that the sources of law must be hierarchicalized.