Law holds a central place within contemporary societies, shaping behaviour, resolving disputes and allocating rights and obligations. Nevertheless, its precise character remains contested. This essay examines the absence of any fixed definition of law and explores the two dominant theoretical traditions that seek to explain it: positive law theory and natural law theory. The discussion draws principally on the works of key jurists to demonstrate the core tenets of each school and to illustrate why legal scholars continue to disagree about the fundamental nature of law.
The Absence of a Static Definition
Legal theorists generally accept that law cannot be captured by a single, timeless definition. Its content and functions vary across jurisdictions, historical periods and political systems. What counts as a valid rule in one society may be rejected elsewhere. Such variability has prompted scholars to approach law through contrasting philosophical lenses rather than attempting a universal description. Two contrasting approaches have proved especially influential: the positivist insistence that law is a human artefact identified by its source, and the natural-law claim that law must satisfy certain moral criteria.
Positive Law Theory
Positive law theory, often termed legal positivism, maintains that law is a product of human will rather than an expression of pre-existing moral order. John Austin’s command theory asserted that law consists of general commands issued by a sovereign and backed by the threat of sanctions (Austin, 1832). This view separates law from morality; a rule may be legally valid even if it is unjust. Later positivists refined this position. H.L.A. Hart replaced Austin’s crude notion of command with the idea of rules, distinguishing primary rules that impose duties from secondary rules that confer powers to create, alter or adjudicate upon those duties (Hart, 1961). For Hart, the ultimate criterion of validity is a “rule of recognition” accepted by officials within the system.
Positivism therefore emphasises certainty and pedigree. Because validity depends on formal criteria rather than moral merit, citizens and officials can identify the law without engaging in moral argument. Critics have observed that this separation may permit morally repugnant regimes to claim legal authority, a concern that emerged sharply after the Second World War. Nevertheless, the positivist account remains attractive for its analytical clarity and its fit with modern constitutional practice, where statutes and precedents determine what counts as law regardless of their substantive justice.
Natural Law Theory
Natural law theory, by contrast, insists that law and morality are conceptually connected. Its classical form, articulated by Thomas Aquinas, held that human law participates in the eternal law discovered through reason; an unjust enactment fails to bind the conscience (Aquinas, 1274). Modern natural lawyers have offered more nuanced versions. John Finnis argues that law must serve basic human goods such as life, knowledge and friendship, and that a system that systematically disregards these goods forfeits its claim to be law properly so called (Finnis, 1980).
This perspective supplies a critical standard against which positive enactments can be judged. During the Nuremberg trials, for example, prosecutors invoked natural-law arguments to deny the legal validity of certain Nazi decrees. Yet natural-law reasoning is sometimes criticised for vagueness: reasonable people may differ over which values count as fundamental and how they should be ranked. Consequently, the theory can appear less determinate than positivism when concrete disputes arise.
Comparing the Two Schools
The contrast between the two traditions highlights different priorities. Positivism privileges predictability and democratic pedigree, enabling officials to apply rules even when they personally disapprove of them. Natural law prioritises legitimacy and justice, warning against blind obedience to immoral directives. Contemporary scholars often adopt intermediate positions; inclusive legal positivists accept that moral criteria may be incorporated into a legal system’s rule of recognition, thereby softening the strict separation thesis (Hart, 1961). Such refinements illustrate that the debate is not merely historical but continues to influence judicial reasoning and constitutional design.
Conclusion
In sum, law lacks a static definition because its character depends on the theoretical standpoint adopted. Positive law theory provides a formal, source-based account that secures predictability, while natural law theory supplies a moral filter that guards against injustice. Each school illuminates important features of legal ordering yet leaves certain questions unresolved. For students of law, understanding both traditions is essential: it encourages critical reflection on the rules that govern society and on the values those rules ultimately serve.
References
- Aquinas, T. (1274) Summa Theologica. Translated by Fathers of the English Dominican Province, 1947. New York: Benziger Bros.
- Austin, J. (1832) The Province of Jurisprudence Determined. Edited by W. Rumble, 1995. Cambridge: Cambridge University Press.
- Finnis, J. (1980) Natural Law and Natural Rights. Oxford: Clarendon Press.
- Hart, H.L.A. (1961) The Concept of Law. 2nd edn. Oxford: Clarendon Press.
