The Roots of the Western Legal Tradition in Theology
Harold Berman (Law and Revolution, 1983) argued that law became an autonomous science in the 12th c. as part of the effort to release the Catholic clergy (esp. the papacy) from the control of secular rulers
The distinctive belief about Western legal science, as promoted in the early universities, is that it was an ongoing project to integrate the legacy of Judaeo-Christian, Greek and Roman wisdom into a universal order for Christendom that would realize human destiny
This reflects the fact that the Roman Empire had become disordered and law was basically being administered at the local level according to custom or the whim of the ruler
From that standpoint, appeals to "natural law" and "divine law" aimed to find some textual precedents for overarching principles that seemed to be operative in best legal practice that could also be used to decide cases when there are conflicting precedents
This reflects the 'subsidiarization' of the law in the Western tradition: i.e. the law permits the existence of subordinate and sometimes cross-cutting jurisdictions
The belief in "natural law" continues to underwrite attempts by such non-theological jurists, e.g. Lon Fuller and Ronald Dworkin, to use resources from the past to forge future policy under the rubric of "moral principle"
One immediate consequence of the new progressive legal science of the 12th c. was the recognition that 'institutions' needed to be created to make the performance of social functions legally explicit and protected (in perpetuity).
This went beyond the distinction between 'gens' (family) and 'societas' (temporary alliances) to include 'universitas' (corporations, including churches, states and, of course, universities)
The law itself became an institution that maintained the collective values of the society; hence, crimes had to be formally identified and punished to satisfy some abstract sense of justice that transcends immediate interests, including keeping the peace -- e.g. it was not enough simply to do penance or even provide some compensation
Natural Law as a Concept Both In and Out of Theology
Ideas relating to 'natural law' predate Christianity. In the Greco-Roman law, it was invoked in conflicts between what a ruler or judge decrees and what the dictates of conscience would seem to require
Sometimes this 'natural law' was associated with family loyalties, e.g. Antigone (person prohibited from burying relative who is deemed a traitor)
In the Christian era, natural law becomes more rationalized and is invoked for potentially more radical purposes: i.e. it is not merely an instinctive response but a judgement as to whether the rule or judge is acting appropriately
Medieval legal academics invoked natural law to instruct and influence secular rulers
Failure to conform to natural law could ultimately be grounds for disobedience and even revolution, if it would cause less harm than continuing to obey an unnatural positive law
With the secularization of the Christian era, natural law metamorphosed into individual rights
This move retained the role of individual conscience that was always crucial to natural law judgements
Today natural law theory is most often invoked in attempts to harmonize and unify different legal systems, e.g. the UN and EU, where not surprisingly 'human rights' becomes a significant covering notion
From Berman's standpoint, this is a secular re-enactment of the origin of the Western legal tradition
What about Islam? The historic movement in this case was the failed separation of the secular from sacred control, rather than the other way around
Positivist Attacks on Natural Law Theory
English jurisprudence from Austin and Bentham to Hart has been the strongest anti-natural law tradition
Much of this has to do with the disproportionate control that unelected clerics and judges had in both Parliament and local parishes.
For the English positivists, "natural law" was an ideological smokescreen (Bentham said human rights were "nonsense on stilts") for the worst features of common law: i.e. the arbitrary imposition of prejudice
In fact, the positivist view that the validity of a legal system simply rests with the power of the sovereign who can command obedience was based on this demystified view of natural law, which the positivists then simply wanted to formalize so that everyone knew what they were being forced to do.
Natural Law responses to Positivism
Lon Fuller raised the interesting argument that "legality" is a fundamental value of the law that must be reciprocally maintained: i.e. both lawmakers and citizens must be able to uphold the law in the same sense (i.e. they believe they are laws worth following)
In contrast, positivists justify the law asymmetrically, since citizens don't need to believe the laws are good, they are simply forced to follow them.
Positivists respond that this is too a high a normative standard for the law to meet: i.e. not only must you obey Big Brother, but you must love him!
Ronald Dworkin argues that natural law is "always already" in play, as evidenced by how judges justify their decisions: there is a dual look backward to fundamental principles and forward to policy consequences, and not simply a mechanical subsumption of a case under a rule.
Positivists respond that Dworkin's a legal theory captures (at most) 'hard cases' but does not capture ordinary cases, which are pretty much matters of judges matching cases to the most obvious legal precedents.
Among the more interesting recent attempts to justify the metaphysics of natural law has been Lloyd Weinrib, who follows Aquinas in seeing the doctrine as a mark of our humanity, as it permits the exercise of free will in a world otherwise ruled by law