We know that human governments often make unjust laws. When we recall the racially discriminatory laws of apartheid South Africa, or the Penal Laws of 18th century Ireland, we know that law has often fallen far short of the standards of true justice.
Natural Law is the shorthand term for what we call the abstract, perfect benchmark of justice against which we measure all laws, and human conduct. The idea of Natural Law is very ancient.
Aristotle said of it: “Natural Law is the law of Nature. For there really is, as every one to some extent divines, a natural justice and injustice that is binding on all men, even on those who have no association or covenant with each other … And so Empedocles, when he bids us kill no living creature, says that doing this is not just for some people while unjust for others: ‘Nay, but, an all-embracing law, through the realms of the sky; Unbroken it stretcheth, and over the earth's immensity.’”
Sophocles' Antigone said of Natural Law: "Not of to-day or yesterday it is, But lives eternal: none can date its birth." This concept of an eternal, perfect law was adopted by the early Christian church. St Thomas said that natural law is "nothing else than the rational creature's participation in the eternal law.” Christian teachings were seen as the most perfect expression of this divine order.
The Renaissance led to the Enlightenment or the Age of Reason which legal scholar Dennis Lloyd called, "the Golden Age of the law of nature … The whole emphasis was now placed on the rational character of natural law."
The US Constitution set out natural and inalienable rights with which men were endowed by their creator. It was giving legal force to ideas until then considered abstract, natural law concepts. The US Constitution is perhaps the ideological forerunner of the fundamental law of most Western democracies. Certainly the Irish Constitution was heavily influenced by it. The US Constitution and the Bill of Rights indelibly associated law and the idea of liberty, but also set out the unique idea that natural rights could be the subject of legal guarantees.
This idea was to gain further force with the development of the idea of innate human rights, which people could enforce legally against their governments. Yet certain interpretations of human rights can produce perverse and unjust outcomes. Human rights law, in reality, is man-made, just as legislation and case law is.
Whenever we say, “that law is unfair”, we are saying that there is a higher standard of justice, which we can discern by conscience and which man-made law fails to meet. We are effectively saying that this or that law does not accord with the natural law. Natural law is therefore something that we all understand instinctively.
Psychological researchers have recently found that even babies possess an understanding of natural law: 15 month-old babies were shown to respond more positively to puppets who acted fairly, and shunned those who acted unfairly.
Natural law is at once comprehensible to a baby, and yet a very complex, abstract and even mysterious idea. Anyone who senses that there is an objective standard of justice and truth believes in natural law. Natural law can be discerned by all humans.
Yet simple fairness, and the natural law that underpins it, is at once obvious to a child, and semi-mystical. Roman Catholic teaching says of it, “The natural law expresses the original moral sense which enables man to discern by reason the good and the evil, the truth and the lie”.
As lawyers, we deal with rules and regulations which can often seem mundane and arbitrary. Yet the whole of our legal system - which has rules for everything from parking fines, to unlawful killing, to contractual disputes - is founded upon the mysterious edifice of natural law.