Natural Law

Introduction

Natural law is a philosophical concept for there being an objective moral order that all rational persons can perceive. Natural law is largely understood to be given by a divine Being and teaches that individuals and political communities must conform to the natural law for both to flourish. 

History

One of the earliest natural law thinkers in political philosophy was Aristotle. In what is considered one of the essential phrases capturing the heartbeat of natural law, Aristotle observed, “Every art and every inquiry, and similarly, every action and pursuit, is thought to aim at some good.”^_[1] Standing within the teleological tradition of moral thought, natural law speaks to the existence of a moral order defined by natural goals, purposes, and ends. For Aristotle, every human being lives according to some account of the good life. The grasp of moral good then informs people how to order their individual lives and their political communities.   

While natural law has long served as the legal backbone for Western order, in the eighteenth through twentieth centuries, sustained attacks on the divine foundations of natural law led to present day conditions where natural law is considered antiquated and a strictly religious concept by its critics. Recent efforts from natural law philosophers such as John Finnis and Robert P. George have, however, led to a retrieval and rebirth of natural law as a serious discipline within jurisprudence.

Etymology

Consider the terms “natural” and “law” etymologically. “Natural” refers to that which just is factual, meaning there is no prior proof apart from assuming its existence. “Natural” speaks to the inherently “self-evident” nature of what is “natural.” For example, Thomas Aquinas holds that the first principle of moral reasoning is known through practical reasoning about the human good: “Pursue that which is good, avoid that which is evil.” For Aquinas and the natural law tradition, that principle is “indemonstrable” in that it cannot be proven, but if there is a true foundational moral principle, its existence would, at an ultimate level, just be. “Law” refers not just to human statutory law, but to the directive rationality for how natural truths are meant to bring us into conformity with reality. To speak of “natural law” means the acknowledgement of an objective standard by which individuals or political communities must conform themselves to in order to achieve the purpose or goal for which individuals or political communities exist.

The Philosophy of Natural Law

Natural law refers to the existence of objective moral standards of right and wrong and the justification for making that distinction. In other words, the natural law testifies to the fact of right and wrong actions and the ability for us to make that distinction through the use of our reason. Typically nested within theological traditions (but not limited to theological traditions), natural law testifies to the reality of a divinely inscribed moral order that human beings as rational agents have the capacity to understand and order their lives by. Since natural law assumes the existence of actual moral wrong and actual moral right, natural law opposes moral relativism, a branch of ethical thought that denies the existence of objective moral standards. 

The natural law tradition has never held that every individual knows every contour of the natural law perfectly or exhaustively. Humans do err and engage in actions that are intrinsically disordered and unjust. Even still, the ability of individuals to experience remorse testifies to the existence of a moral law that is known through violating it. 

Aquinas’s famous definition of Law from question 90 of the Summa Theologiae helps us put the pieces together of how natural law functions. According to Aquinas, “Law” is “an ordinance of reason for the common good, made by him who has care of the community, and promulgated.” What Aquinas means is that (1) all justly constituted human law is of the type that satisfies the demands of reason, (2) is issued from a proper authority, (3) aims at the common good of all, (4) and is publicly disclosed. Put simply, “law” is reasonable action given by an authority for the good of all. While Aquinas’s definition is applied in the setting of human law, it also applies on a cosmic scale as well. First, for Aquinas, the divine Being (i.e. God) would only issue a law that conforms with the divine Being’s own nature. Second, a divine Being would only issue law that is sensible, directive, and intelligible for all persons. Third, the divine Being is properly situated as the highest possible authority in the universe and thus rightly situated to issue such ordinances. Fourth, the divine Being would need to make the law knowable. 

“We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.” – American Declaration of Independence.

Components of the Natural Law

To better understand the details of natural law, explaining the constitutive elements of natural law and natural law theory is crucial.

Origin

While various traditions have their own account of the origins of the natural law, the consensus around the natural law is that it is the product of a divine mind. For a moral law to exist that is not determined by consensus or majority alone, a divine Being would have to bring such a law into existence and order such a law to the end that the divine Being sees fit.

Knowability

The natural law tradition holds that the rational ability of human beings enables them to grasp the natural law. Their heightened capacity for reason, self-awareness, and self-transcendence separates human beings from the rest of creation. Furthermore, the natural law tradition argues that patterns and regularities in creation’s design give evidence of natural laws as well as the existence of the conscience bearing witness to a law “written on their hearts” (Romans 2:15). The knowledge of the natural law has thus both physical (creation) and non-physical (conscience) components.

Content

While various natural law traditions propose their own precise entailments of natural law, one settled consensus is that natural law is where an account of justice is found. To take two maxims that are both religious but also understood as natural law truths, Jesus Christ teaches that (1) “You shall love your neighbor as yourself.” (Mark 12:31, ESV); (2) “And as you wish that others would do to you, do so to them” (Luke 6:31, ESV). While these verses come from the Christian tradition, both verses reflect what must be understood as a self-evident truth of the natural law. These maxims assume a rational agent’s grasp of moral goods that benefit their nature. Both verses imply that rendering each person what is due to them originates from a person’s understanding of what they are owed first. Such a truth is a matter of reciprocal justice. For example, if I would not have my bicycle stolen, I should not steal someone else’s bicycle, either. This natural law formula begins with understanding what is due to oneself. Knowledge of what one is owed requires understanding the existence of an innate truth that should be obeyed and, in turn, extended to others.

Utility

As a matter of first principles pertaining to sound political order, natural law’s primary value is providing political community members with a common or shared moral vocabulary – a shared set of moral values. Political communities comprise individuals whose worldviews form inevitable clashes due to varying opinions and disagreements in society. Natural law teaches that those disagreements can extend only so far until the very viability of the community is at stake. A political community cannot persist without addressing fundamental questions of basic justice. Natural law thus offers a minimal account of political morality necessary to sound political order and human flourishing.

Philosophical Assumptions of the Natural Law

Understanding the fundamental philosophical pillars of natural law theory is important. The four components—universality, objectivity, intelligibility, and obligation—form the underlying superstructure of natural law as a concept. For natural law to be what it proposes, it must retain these four components.

Universality

Natural law assumes the laws it posits are universal in nature, meaning they are always valid in all places and throughout history. Any morality that is less than universal would not be binding. 

Objectivity 

Objectivity speaks to the brute fact of the natural law’s existence. To be “objective” means that the moral principles that the natural law proposes do not merely appear to be true but are objectively “there” as true and self-attesting facts. As all water molecules have two hydrogen molecules and one oxygen molecule, all maxims of the moral law inhere within reality, or else morality is just a façade.

Intelligibility

Intelligibility speaks to the possibility of the natural law being graspable, meaning that we can say that not only does the natural law exist as a concept, but we can grasp the natural law itself and order our lives in response to its demands. This occurs through reasoned deliberation on moral goods that complete us as human beings.

Obligation

Obligation provides natural law with the need to follow it. A moral truth that exists but need not be followed could not posit any binding authority upon us. Because universality, objectivity, and intelligibility set the stage for the natural law’s authority, the natural law tradition argues that because the natural law is meant to direct our natures and our communities toward their proper end, we are duty-bound to obey the natural law. Because natural law is good, it is rightly considered authoritative, and because of the nature of its authority being promulgated by a divine Being, it is therefore obligatory on us.

Conservative Perspective

Natural law is at the center of the conservative tradition’s understanding of the relationship between liberty and order. According to the conservative tradition, the natural law anchors political freedom, limited government, and the necessary ingredients that sustain both: moral rectitude and self-government. If a people are to stay free and the government limited, both must know their place in the universe under a divine Sovereign. 

Natural law covers an enormous range of historical figures. From the classical period and individuals like Aristotle to the high watermark of natural law thinking in Aquinas’s medieval period and recent figures such as Russell Kirk and Robert P. George, natural law has formed the backdrop to the conservative tradition’s thinking about morality, moral obligation, and the common good. Essential pillars of human civilization’s survival are intrinsic to natural law thinking Truth, morality, family, authority, and liberty. Each of these concepts is emptied of coherence without a natural law underpinning them. The Declaration of Independence is unintelligible apart from the natural law. For the conservative tradition to continue to champion the truths it believes are essential to sound order, it must work to conserve and champion the natural law.  

Some within the conservative tradition are suspicious of the natural law’s universalizing claims and argue that moral knowledge is developed through local custom and inherited tradition. In this school of thought, however, there is not a total rejection of moral truth, only that moral truth is not known through broad universal maxims or that truth is the product of a divine Being.  

Speaking comprehensively of the conservative tradition overall, conservatism has always stood for an overarching embrace of natural law.

Practical Consideration: Nuremberg Trials

Natural law is the idea that much of modern progressivism scoffs at but cannot entirely evade or deny. Consider one of human history’s most famous moral events: The Nuremberg Trials. There sat the Nazi perpetrators who had to answer for their heinous crimes. But how would they be tried against a body of international law that was still developing? The answer was the natural law. United States prosecutor and Associate Justice of the United States Supreme Court, Robert H. Jackson, delivered the opening statements. Though the phrase “natural law” itself is not present in Jackson’s speech, the concept is pregnant throughout Jackson’s opening remarks. He understood that not only were the Nazis on trial, but so was the question of whether political communities could allow wicked injustice to go unchecked. As the natural law witnesses to certain moral facts that everyone just knows by virtue of being human, the condemnation of the Nazis at Nuremberg was heralded as a just action. 

From the Declaration of Independence to the Nuremberg Trials, conformity to the natural law is both the beginning, the sustaining force, and end of all political communities.

Suggested reading

• Andrew T. Walker, Faithful Reason: Natural Law Ethics for God’s Glory and Our Good (Nashville: B&H Academic, 2024) 
• C.S. Lewis, The Abolition of Man. San Francisco: HarperOne, 2015. 
• Jacqueline A. Laing and Russell Wilcox, eds., The Natural Law Reader, 1 edition (Hoboken, New Jersey: Wiley-Blackwell, 2013) 
• Robert P. George, Clash of Orthodoxies: Law, Religion, & Morality In Crisis (Wilmington, DE: Intercollegiate Studies Institute, 2001) 
• Thomas Aquinas, Treatise on Law: The Complete Text, trans. Alfred J. Freddoso, 1st edition (South Bend, IN: St. Augustine’s Press, 2009) 
• David VanDrunen, Natural Law: A Short Companion (Nashville: B&H Academic, 2023) 
• John Finnis, Natural Law and Natural Rights, 2nd ed. (Oxford: Oxford University Press, 2011)