Two of the general theories of law, legal naturalism and legal positivism, had and continue to have an enormous influence on law throughout history. Those engaged in different pursuits may, however, find one general theory to be of greater use for their particular ends--regardless of their personal conviction as to the superiority of one or the other. Historians, lawyers, and social critics, for example, invoke law for very different purposes and may view one general theory as having greater explanatory power.
All of these activities is, of course, will at times rely on their understanding the implications of both these theories but, in general terms, the historian will find legal naturalism to be of greater utility to the extent that s/he is engaged in understanding the underlying world-views and motivations of peoples in various times and places. The historian engaged in studying laws, however, may find a positivist, universal theory, such as normative theory or the analytical positivism of rule theory, better suited to her/his purposes. The lawyer, on the other hand, is bound by positive law and is interested in what is, rather than what ought to be. Legal positivism is, therefore, of far greater use to her/him since it assumes that it is the law as it is--remote from concerns with justice--that matters and that the law's right to command or to enforce itself is derived, on some rational basis, from the sovereign will of the state, from norms, or from rules. It is not unlikely, however, that the lawyer may turn occasionally to the invocation of some type of natural law, as it serves her/his purpose, to propose solutions based on notions of justice that derive from reason, virtue, or even God. The social critic may quite commonly use either theory or both since s/he can be interested in whether law serves justice, as conceived of within whatever higher truth s/he advocates or may wish to address very directly the question...