Legal Theory Lexicon 065: The Nature of Law

Introduction

What is the nature of law?  This question has occupied center stage jurisprudence and philosophy of law in the modern era, and has been the central occupation of contemporary analytic jurisprudence.  This entry in the Legal Theory Lexicon aims to give an overview of the "What is Law?" debate.

Historically, the answer to the question, "What is law?," is thought to have two competing answers.  The classical answer is provided by natural law theory, which is frequently characterized as asserting that there is an essential relationship between law and morality or justice.  The modern answer is provided by legal positivism, which, as developed by John Austin, asserted that law is the command of the sovereign backed by the threat of punishment.

Contemporary debates over the nature of law focus on a revised set of positions.  Legal positivism is represented by analytic legal positivists, like H.L.A. Hart, Joseph Raz, and Scott Shapiro. There is another strand of legal positivism that is represented by Hans Kelsen; this version is very influential in Europe and elsewhere, but not as prominent in Anglophone legal philosophy.

The natural law tradition is defended by John Finnis.  And a new position, interpretivism is represented by the work of the late Ronald Dworkin.

In some ways, the title of this Lexicon entry is misleading, because of our focus on the "What is law?" question as it has been approached by contemporary legal philosophers.  There are other important perspectives on the nature of law that focus on law's functions rather than the the meaning of the concept or the criteria of legal validity.  For example, the sociological tradition includes important work on the nature of law by Max Weber and Niklas Luhmann.  These issues are discussed by Brian Tamanaha in the article cited in the Links section at the end of this entry.

This Lexicon entry maps the territory of the "What is Law?" controversy, and provides introductory sketches of the major positions.  As always, the Lexicon is written for law students, especially first-year law students, with an interest in legal theory.

Natural Law Theory

Natural law theory is strongly associated with classical and medieval thought, especially Aristotle, Roman jurisprudence, and St. Thomas Aquinas.  There are several challenges associated with the task of explicating natural law theory, and one of the most important tasks of this introductory entry is simply to identify these challenges.

First, there are two interrelated but distinct views that are called "natural law theory."  One is a view about the nature of morality: this view asserts that there are natural moral laws, and it is not essential to this view that it take any particular stand on the "What is law?" debate.  A second view that is called "natural law theory" is a theory about "law" as an institution or practice--that is the view that is implicated in the "What is law"" controversy.

Second, contemporary understandings of "natural law theory" have been strongly influenced by the legal positivists critique.  When the positivists articulated the theory they were criticizing, their articulations of natural law theory were neither charitable nor true to the natural law tradition.  When Holmes referred to a "brooding omnipresence in the sky" he was not offering a sympathetic or charitable reading of the natural law tradition.

For the purposes of this broad overview, we might use the latin phrase lex injusta est non lex as a starting point.  Natural law theory could be understood as affirming something like the following:

An unjust "law" is not a true law.

This formulation differs from a literal translation--an unjust law is not a law.  Formulated in that way, natural law theory seems to be committed to a contradiction: something which is a law (but also is unjust) is not a law.  The quotation marks around "law" and the phrase true law make it clear that natural law theory is asserting something else, that something which might be called a "law" is not in fact a law if it is unjust.  Usually, this notion is accompanied by some explication of the characteristics that are required for status as a "true law," a "focal case of law," or perhaps "valid law."

Legal Positivism

It is difficult to know where the positivist tradition begins.  Hobbes's theory of law shares some characteristics with the theories offered by Jeremy Bentham and John Austin--both of them clearly in the positivist tradition.  Jeremy Bentham developed a very sophisticated version of legal positivism, but for a variety of reasons, the more influential and widely known view was that of Bentham's student, John Austin, the author of The Province of Jurisprudence Determined (1861).

Austin's theory was that a given rule was a law if and only if the rule was the command of the sovereign to subjects of that sovereign backed by the threat of punishment.  A sovereign is some person or institution who is habitually obeyed in a well-defined territory, but who or which does not habitually obey any other person or institution.

Austin's positivist theory does an excellent job of explaining the rules of criminal law, which forbid certain actions and impose punishments on those who engage in the forbidden actions.  But this theory has a difficult time accounting for other aspects of law, and especially for those rules that create legal powers, such as the power to create contracts, trusts, wills, and so forth.  This difficulty is most acute with respect to rules that define the basic institutional arrangements that define the sovereign itself, e.g., the rules of constitutional law in the United States.

These deficiencies in Austin's theory prompted H.L.A. Hart to develop a more sophisticated version of legal positivism.  One feature of that theory is the distinction between primary rules (which would include criminal prohibitions) and secondary rules (which allow for the creation, alteration, and termination of primary rules).  Hart replaced the notion of a sovereign with that of a rule of recognition--a social rule that specifies what counts as a law and what does not.

Moral Facts, Social Facts, and Legal Content

The contemporary approach to these issues is the product of almost sixty years of thinking within the tradition that is sometimes called "analytic jurisprudence."  Beginning with the work of H.L.A. Hart in the 1950s, through is publication of The Concept of Law in 1961, and extending through Ronald Dworkin's critique of Hart, and the reformulation of the positivist tradition by both Joseph Raz and Jules Coleman, the basic issues and questions have gone through several transformations.

One useful way to get get at the heart of these developments is to conceive of the debate about the nature of law as centrally concerned with the relationship between social facts, moral facts, and legal content.  Our question is "What determines legal content?," where "legal content" is simply understood as the content of the legal norms.

• One answer to this question takes the form: It is necessarily the case that only social facts determine legal content.  This is exclusive legal positivism--a view that is strongly associated with Joseph Raz.
• A second answer to this question takes the form: It possibly the case that moral facts determine legal content, but only if social facts give the moral facts this role.  This is inclusive legal positivism--and this view is most strongly associated with Jules Coleman.
• A third answer to the question takes the form: It is necessarily the case that moral facts determine legal content.  This view would include natural law theory and interpretivism--the view that is strongly associated with Ronald Dworkin.

By framing the "What is law?" debate in terms of the relationship between social facts, moral facts, and legal content, the conceptual space we get precise mapping of the conceptual space.  In the rest of this Lexicon entry, we will take a somewhat less shallow look at the three options.

Inclusive and Exclusive Legal Positivism

Exclusive legal positivism is the view that only social facts can determine legal content.  Joseph Raz famously argued for exclusive legal positivism based on the premise that law claims authority, that authority consists in displacing other reasons for actions, and therefore law must displace moral reasons for action.  (That was a very short and inadequate summary of a long and complex argument.)

Inclusive legal positivism is the view that moral facts can play a role in determining legal content, but only if there are some social facts that give the moral facts this role.  For example, a constitution might include an clause that make a moral conception of human equality a legal rule.  This would give the morality of equality a role in determining legal rights, but this role would exist because a social fact (the Constitution) made it so.

Contemporary Natural Law Theory

The positivist critique of classical natural law theory resulted in a major restatement by John Finnis.  Finnis's theory is subtle and complex and no thumbnail sketch can do it full justice, but for the purpose of the Lexicon, one of his ideas can serve to illustrate the flavor of his theory.  Finnis argues that the natural-law claim that an unjust "law" is not a true law can be explicated via the idea of the "focal meaning" of "law."  This argument that concedes that unjust enactments are "laws" in a sense, but that that the focal sense of "law" is limited to laws that are not unjust.  Finnis's position has both critics and defenders, but his magisterial book Natural Law and Natural Rights is must reading for anyone interested in contemporary natural law theory.

Interpretivism

The final view is "interpretivism," strongly associated with Ronald Dworkin.  For Dworkin, social facts, such as constitutions, statutes, and court decisions, do not directly determine legal content.  Instead, Dworkin believes that the content of the law is given by the theory that best fits and justifies the legal materials.  Dworkin makes this theory vivid by imagining a judge, Hercules, who is able to construct a grand theory of political morality that provides a constructive interpretation of the entire institutional history of a given society.  Because this theory is a theory of that institutional history, it is constrained.  For example, the best constructive interpretation of the institutional history of the United States will have to acknowledge that our federal legislature is bicameral and that it includes a Senate with equal representation of each state.  But this constraint does not require a perfect match between a literal interpretation of every legal text and the content of the law.  So some precedents may be categorized as mistakes, and some statutory or constitutional provisions may be given a constructive interpretation that makes them morally more attractive but does not follow every jot and tittle of the text.

Conclusion

This very brief introduction to the "What is law?" debate is necessarily incomplete and shallow.  But I hope that it gives you a general sense of the various positions that have been taken on the nature of law.

Related Legal Theory Lexicon Entries

• Legal Theory Lexicon 032: Fit and Justification
• Legal Theory Lexicon 038: The Internal Point of View
• Legal Theory Lexicon 039: Primary and Secondary Rules
• Legal Theory Lexicon 044: Legal Theory, Jurisprudence, and the Philosophy of Law

Bibliography

• John Austin, The Province of Jurisprudence Determined (1861).
• Jules Coleman, The Practice of Principle: In Defence of a Pragmatist Approach to Legal Theory (2001).
• Ronald Dworkin, Law's Empire (1986).
• John Finnis, Natural Law and Natural Rights (1980).
• H.L.A. Hart, The Concept of Law (1961) (2d ed. 1984).
• Joseph Raz, The Authority of Law: Essays on Law and Morality (1983).
• Scott Shapiro, Legality (Harvard University Press 2011).

Resources on the Internet

• John Finnis, Natural Law Theories, Stanford Encyclopedia of Philosophy.
• Leslie Green, Legal Obligation and Authority, Stanford Encyclopedia of Philosophy
• Leslie Green, Legal Positivism, Stanford Encyclopedia of Philosophy.
• Andrei Marmour, The Nature of Law, Stanford Encyclopedia of Philosophy.
• Nicos Stavropoulos, Interpretivist Theories of Law, Stanford Encyclopedia of Law.
• Brian Tamanaha, Law, Oxford International Encyclopedia of Legal History, 2008.

(This entry was last revised on April 24, 2022.)