Within politics and society, the topic of "human rights" has become a popular term and an end which many governments and international organisations pursue. The concept of human rights as moral principles that set standards for human behaviour is found within major documents that form the basis of international, regional and national laws: the Universal Declaration of Human Rights, the European Convention on Human Rights (ECHR) and, arguably, the United States Constitution. These documents place emphasis on inviolable rights inherent to human beings. However, the simple existence of these laws begs the question, "what is the moral basis for their existence?". If one believes that the Universal Declaration or ECHR contain moral force, then what is the basis for this morality? Though both are examples of positive law, or law enacted by human institutions, it only provides a superficial basis for their moral significance.
Natural law theory has sought to answer this question and provide an explanation that connects positive law and morality. The theory has been widely misunderstood by numerous philosophers of law and has lost much of its popularity in modern society, with the exception of the Roman Catholic Church. Nevertheless, in examining the history of the theory from antiquity to modernity, we can consider the implications of natural law theory within the domain of human rights.
Natural law theory emerged with Aristotle’s Rhetoric in which he notes that two facets of law exist: the particular and the universal. The particular law, he writes, is the law "which each community lays down and applies to its own members" - what we now consider positive law. He describes the universal law as "the law of nature" such that everyone knows what is just and unjust according to their human reason. The Roman orator Cicero later discusses natural law within his De Re Publica and De Legibus. Cicero’s view reflects that of Aristotle:
"That nature has granted to a human being, how many of the best things the human mind encompasses, what service we have been born for and brought into light to perform and accomplish, what is the connection among human beings, and what natural fellowship there is among them. When these things have been explained, the source of laws and right can be discovered."
Cicero, like Aristotle, also considers that the natural law is not something necessarily tied to the nature of being human, but rather that human reason is inherently good. Cicero does mention that the nature of the world necessitates right and wrong action but in accordance with the idea that human reason can naturally discern what is right and wrong.
Moving past the age of antiquity, natural law theory saw itself invoked by the great Catholic philosopher and theologian Thomas Aquinas. Aquinas’ Treatise on Law found within his magnum opus the Summa Theologica, begins with the concept that law pertains to right reason. Reason, according to Aquinas, directs human acts towards their end. The "end" that human beings seek through their use of reason is the common good.
Thus, the natural law is defined by Aquinas as a participation within the eternal law of God. As "rational creatures," we "receive our ‘respective inclinations to… proper acts and ends’." To the modern reader, it may seem as if Aquinas argues that the natural law results from divine commands. Instead, he articulates that "the light of natural reason, whereby we discern what is good and what is evil" is central to the Thomistic theory of natural law. It is neither a theory of divine commands nor a belief that ethical propositions can be derived from the bare facts of human nature but a theory that prioritises the use of human experiences and reason to uncover that which is good and that which is evil.
John Finnis expands upon the Thomistic analysis in his work Natural Law and Natural Rights by advocating for a set of seven "basic goods" that enable human flourishing and that ought to be pursued as ends within themselves. These are:
Life
Knowledge
Play (recreation)
Aesthetic experience
Friendship
Practical reasonableness
"Religion"
Finnis provides only the goods which he takes to be self-evident and fundamental to human life. To pursue these basic goods and achieve well-being, Finnis recommends "respect for every basic value in every act." He maintains that any act that damages a basic good simply ought not to be committed regardless if one thinks that preferential consequences may be obtained from the act.
While one may think that Finnis’ this philosophical underpinning of rights and duties is identical to Kantianism or Lockeanism, both of these views do not attempt to justify a wide set of protected basic goods that contribute to the continual pursuit of well-being within one’s life but are limited in the specific duties or rights that an individual person has. Locke discusses only the negative liberties of life, liberty and property and Kant, the duties towards oneself and others. The natural law theory of human rights integrates aspects of these, notably Kant’s categorical imperative, in order to create a comprehensive image of human life and the moral values that follow from it.
How then do human rights laws relate to the natural law theories of Cicero, Aquinas and Finnis? Human rights laws ought to reflect the basic goods or values that encourage human well-being and the achievement of common good. Natural law theory (especially Finnis’ extension of it) provides a philosophical basis that reflects many of our moral intuitions regarding human rights (and their abuses). Whether it is the persecution of Christians in the Middle East, or of the Uyghurs in China, natural law theory strikes down each of them as deeply contrary to the moral order.
If unsupported by a moral theory or belief in moral order, human rights law quickly becomes a farce. Natural law theory, despite its modern connection with political conservatism, offers sufficient means of grounding our discussion about human rights and ought not to be rejected for its insights.