What is Natural Law
The roots of natural law theory reach back to the ancient world, where thinkers such as Aristotle laid the groundwork for subsequent formulations of the theory. One of the earliest formations of what we would consider to be natural law theory appears in Aristotle’s Nicomachean Ethics, written in the 4th century BCE. Aristotle wrote that there is a distinction between general justice and political justice, saying that the former "is the law common to all mankind," while the latter "is the appointment of a civil community by reference to the nature of the polity." General justice, according to Aristotle, was a sort of moral standard to which laws and practices could be compared, while political justice was that which could be enforced in a given political body.
The natural law theory that most people are familiar with today was further refined a few hundred years later in the writings of St. Thomas Aquinas, who lived in the 13th century CE. In his Summa Theologica, Aquinas wrote that natural law was that which human beings participate in by virtue of our ability to use reason; it is the reasoned discernment of good and evil. As Aquinas explained, "Every human being possesses some degree of knowledge…concerning those goods which the natural law prescribes . And therefore the law according to which every being acts is prescribed to man by reason, which shares in the eternal law." Though Aquinas did not invent natural law theory, he was influential to its development, as his writings were thought to represent a successful reconcilement of pre-Christian philosophies with Christian doctrines. Aquinas’ formulation of natural law held a significant influence in the Middle Ages, where it was understood as flowing from the divine intellect, and also during the Renaissance, where secularized, non-Christian conceptions of natural law began to take root due to the advent of humanist scholarship.
Aquinas’ reasoning was critiqued by later thinkers in the Enlightenment, particularly by Enlightenment philosophers such as Samuel von Pufendorf in the 17th century and Thomas Hobbes in the 18th century, among others. They argued that the concept of natural law was demonstrably untenable; however, both Pufendorf and Hobbes agreed that laws were only binding if they were in accord with the consent of the majority of the political body. To a certain extent, this laid the groundwork for the social contract theories of enlightenment political philosophers, such as John Locke and Jean-Jacques Rousseau, who advanced models for the origin of political organizations that did not rely on divine will or tradition.
Natural Law compared to Legal Positivism
Natural law theory posits that law must be based on a universal moral order to be legitimate. Legal positivism, in contrast, holds that law is man-made and essentially arbitrary; what constitutes ‘law’ may change from society to society, as long as its creation and application adhere to the proper procedure.
Natural law theory’s emphasis on ethics can be traced back to Aristotle, who theorized that natural law was based on the idea that government had its origins in nature, not popular consensus. Thomas Aquinas adapted Aristotle’s work in the 13th century by adding Christian theology to it. His conception of natural law remained dominant in legal theory until the Enlightenment.
Two major figures in the rebirth of natural law theory were Thomas Hobbes and John Locke. Hobbes said basic rights, including the right to life, liberty and property, predate the sovereignty of states. They spring from natural law, which self-evidently teaches that such rights cannot be legitimately taken away by kings or other rulers. In "Two Treatises of Government", Locke added the idea of the social contract: that governments could exist only when they had the consent of the governed.
Legal positivism arose in the 19th century. Jeremy Bentham, founder of the utilitarian movement, is often credited as the first modern legal positivist. According to Bentham, man-made laws are best understood as statements of social facts about what most people in a society believe. John Austin, Bentham’s student, articulated the heart of legal positivism in the 1832 work "The Province of Jurisprudence Determined": "A law, which exists merely as an opinion, or as a command, or even as a rule, is a positive law; and for an inquiry concerning the law, the law as it has been historically is our only record."
Renowned jurist H.L.A. Hart further developed the idea of legal positivism in his seminal 1961 book "The Concept of Law." Hart introduced the notion of the rule of recognition: a legal test by which a society can determine which rules will count as law. It is not itself law. Some legal positivists in the latter half of the 20th century were skeptical of natural law theory, arguing that it created vagueness and uncertainty in the law.
Key Historical Influence on Modern Jurisprudence
The legacy of natural law extends significantly beyond the writings of the past and the theories of the great philosophes. The enduring impact of natural law is manifested in numerous contemporary legal systems. Such systems frequently undertake to safeguard individual rights or to ensure that justice prevails, a goal which continues to animate democratic legislation, including those based on human-rights law, anti-discrimination law, or even in the realm of ordinances which guarantee the freedom of expression in content-neutral language.
Some of the principles that continue to underpin laws today draw on natural law theory. For example, anti-discrimination laws in many countries are rooted in a notion of equality. A foundational principle in Hobbes’ natural law theory was the right to self-preservation. Exponents of natural law who promoted a right to consider oneself a person (or moral agent) chimed the need to grant persons a state of protection from arbitrary power, of the kind that excludes them from certain benefits (such as non-discrimination in employment opportunities, a right to travel and others).
In some national legal systems, such as that of the United States, the influence of natural law theory is more pronounced, typically reflected in the clauses entrenching the rights to due process and equal protection of the law (which ushered in the principle of equality). In some cases, international human rights law explicitly relies on natural law tenets. This is arguably the case in provisions entrenching the right to life in the African Charter on Human and Peoples’ Rights, which make no reference to life being a right or entitlement, but rather, "it shall be prohibited." This language evokes principles contained in natural law discussion, including the use of the phrase nullum crimen nulla poena sine lege, meaning "no one can be punished except under a law that establishes the punishment," which underlines the idea that only legislatures can decide what actions are crimes and what the appropriate punishments are for them, and nulla poena sine lege, meaning "no punishment without law," which conveys the principle that no one could be punished under a law retroactively.
Yet, for all its influence, natural law has not gone uncontested and has been criticized on several grounds, especially with ideas championed by the modernists. When the ideas of a few thinkers still hold sway obscuring questions of legitimacy, policy and legitimacy may not even be raised. This is normal — how much rigor can we expect from 21st-century students in their explorations of centuries-old writing? This is certainly why some look at this supposed resurgence of natural law and see merely evidence of ‘naturalism’ rather than ‘natural law.’
Criticism for Natural Law Theory
Notwithstanding natural law theory’s storied history, there are a number of important critiques. Leading this list is the supposition that these moral principles are too subjective. In particular, one common complaint is that even when individuals agree on moral principles, the application of these ideals will vary and thus moral presumptions are inconsistent. While most people would agree that treating another person with respect is a good thing, what that really means in the context of a relationship or transaction may vary widely. Some may feel that such respect means deferring to another’s authority, while others may interpret the same behavior as "talking down" to the other person . Ultimately, then, the definition of respect may depend on the individuals involved.
Another critique is that natural law exists without empirical support. Put another way, these moral principles supposedly exist independent of human behavior and, for this reason, have no empirical basis that supports them. The third objection arises due to disagreements in the application of the purported moral values. Here again, one may look to the many different established philosophies that have emerged from this tradition along with the disagreements that have arisen among them. This disagreement among philosophers, as well as the aforementioned subjectivity may be seen as logical evidence that natural law does not exist.
International Law and Natural Law
In the international arena, natural law theory has also influenced legal and political thought. It provided the intellectual underpinnings for the moral considerations of sovereignty and equality among nations and gave birth to important twentieth-century principles of law, such as the prohibition of genocide, the protection of minority groups, and, of course, basic human rights. Today, familiar international legal concepts such as relative legality, proportionality, fairness, the rules against retroactivity and ex post facto laws, the prohibition against bills of attainder, international obligations enshrined in the principle pacta sunt servanda, and the codification of natural law principles in covenants, treaties, and declarations are today the best examples of natural law theory manifesting itself in positive law at an international level. For example, the various preambles to the United Nations Charter refer to ideals such as the dignity and worth of the human person, the journal good order, the promotion of social progress in larger freedoms, and the advancement of human rights principles. The International Covenant on Civil and Political Rights incorporates the rights to liberty and security of the person, freedom of movement and privacy, freedom of thought, conscience, and religion; the International Covenant on Economic, Social and Cultural Rights proclaims the right of all peoples to self-determination, the right of everyone to work, to just and favorable conditions of work, the right of everyone to form trade unions, the right of everyone to social security, the right to an adequate standard of living, to physical and mental health, to education, to enjoy the benefits of cultural life and scientific progress and its benefits. All these rights and freedoms, codified in the two principal international human rights instruments of 1966, enjoy a broad consensus among states parties.
Future role of Natural Law in Jurisprudence
As complex legal issues continue to emerge in an increasingly interconnected world, the future of jurisprudence inevitably leans towards a consideration of moral principles such as those espoused within natural law theory. In this light, natural law may very well prove to be a touchstone as the legal field adapts to shifting international norms and humanitarian concerns. In particular, issues such as global climate change, international human rights, and bioethics regarding life extension and genetically modified organisms pose questions that arguably go beyond merely practical , technical considerations. These are questions that seek a resolution in the realm of ethics and morality. Legal scholars and practitioners may find natural law theory increasingly relevant as they confront these new challenges in a globalized world. Framed in these terms, the principles espoused by thinkers such as Aristotle, Thomas Aquinas, and Martin Luther King may prove to be a logical foundation for new jurisprudence and legal doctrines that are as yet unimagined.