What makes a theory of law a natural law theory?

A natural law theory of law is grounded in the idea that there are inherent and objective principles of justice and morality that underlie and guide human legal systems. These theories posit that the validity of legal rules is not solely dependent on human-made laws but is instead derived from a higher, universal order or natural law. Several key features characterise a natural law theory of law:

Objective moral order: Natural law theories posit the existence of an objective moral order that is inherent in the nature of humanity or the world. This moral order is seen as discoverable through reason and is not contingent on the whims of individuals or societies.

Universal principles: Natural law is considered universal, meaning that it applies to all individuals, cultures, and societies regardless of their specific legal systems. The principles of natural law are thought to be applicable to human conduct and morality across time and cultures.

Reason as a source of law: Natural law theories emphasise the role of reason in understanding and discerning the principles of natural law. Unlike positivist legal theories that rely solely on enacted laws, natural law theories contend that individuals can use reason to recognise and understand fundamental principles of justice.

Connection between law and morality: Natural law theories assert a close connection between law and morality. According to these theories, the legitimacy of legal rules is tied to their conformity with moral principles. Thus, a law that violates fundamental moral principles may be considered unjust and, in some cases, may be seen as no law at all.

Inherent rights: Natural law theories often recognise the existence of inherent or natural rights that individuals possess simply by virtue of being human. These rights are not created by governments but are considered pre-existing and inalienable.

Ethical foundations of legal systems: In natural law theories, the ethical foundations of legal systems are emphasised. The goal of law is not merely to maintain order or reflect the will of the sovereign but to promote justice and align with moral principles.

Hierarchy of laws: Natural law theories may propose a hierarchy of laws, suggesting that human-made laws should conform to and be consistent with higher, natural laws. If there is a conflict between a positive law (man-made law) and a natural law principle, the latter is considered superior.

Immutable principles: Natural law theorists often argue that certain principles are immutable and do not change over time. While positive laws may evolve and change, natural law principles are seen as enduring and consistent.

Notable historical proponents of natural law theories include figures like Aristotle, Thomas Aquinas, and John Locke. While natural law theory has faced criticisms and alternative perspectives throughout history, it continues to influence discussions on legal philosophy and the foundations of justice.