Alexis de Tocqueville noted that every generation must develop anew the habits, knowledge, and dispositions necessary to support the free and flourishing society—especially a democratic system of governance like our own.

As Niccolò Machiavelli wrote in his Discourses, “For as good manners cannot subsist without good laws, so those laws cannot be put into execution without good manners.”

For the ancient Romans, the civitas, or city, was composed of a group of cives—citizens united by common laws. The laws of the civitas offered citizens the rights of citizenship, but also bound them to certain obligations. These rights and obligations among citizens were the premise of the civitas. Each citizen was born into the laws, rights, and duties of the civitas, and each citizen had to abide by them to remain part of it.

Several prominent seventeenth- and eighteenth-century political theorists—such as Benedict Spinoza, Thomas Hobbes, John Locke, and Jean-Jacques Rousseau—developed the concept of a “social contract,” an agreement about the unwritten mutual duties between citizens and government. Formal political arrangements—such as the external constraints of government, including laws passed by Congress—are important. Equally important, however, are the internal constraints that individual citizens place on themselves to govern how they interact with their fellow citizens. While the social contract pertains to the vertical relationship between citizens and their government, civility is the unwritten, unspoken contract that governs horizontal relationships between us.

In short, civility is the social contract that supports the social contract. Without it, our free way of life will cease to exist. Because of this, democracy depends on civility. In his book The English, Jeremy Paxman wryly claims the English invented manners “to protect themselves from themselves.” But the English didn’t invent manners—in fact, they’re coeval with the human species, and the subject matter of the oldest book in the world, The Teachings of Ptahhotep, given to us from ancient Egypt. But Paxman rightly notes why our social norms support the social contract: civility requires us to commit to living in community, to protect ourselves from the worst elements in our nature, and to make certain sacrifices to maintain life together.

As we’ve learned, our self-love and love of others—our selfish and social natures—have been in tension as long as human communities have existed. To restrain mankind’s selfish impulses and allow its social nature to flourish, communities have created formal and informal institutions so we can live together. Formal institutions include laws and systems of government. Informal institutions involve the unwritten cultural norms that help us navigate social life.

The formal institutions of the United States—federal, state, and local governments, the courts, and more—were established by our founders to limit the negative consequences of people’s innate drive toward self-preservation. Our formal institutions deter and protect us from thieves who might want to rob us and companies that might want to defraud us.

Geoffrey Nunberg, a twentieth-century American linguist, wrote, “Civility and incivility are the words you reach for when you want to suggest that the behavior you’re concerned about isn’t just a breach of manners, but a threat to the health of the civic sphere.”

Benjamin Franklin said, “ Only a virtuous people are capable of freedom. As nations become corrupt and vicious, they have more need of masters.”

But these formal institutions by themselves are insufficient for a free and flourishing society. They only address the most egregious examples of our innate selfishness. To prevent petty acts of selfishness in our everyday interactions would require a much more invasive role for government than most people are willing to tolerate. To avoid government overreach, we need informal cultural norms of self-governance and self-sacrifice—norms that encourage honesty, demonstrate trustworthiness, and promote consideration of the needs and well-being of our fellow citizens. Formal institutions, such as laws and courts, can promote the selflessness needed for social living. But it’s up to us to sustain it.

As Jonathan Swift notes, “Few states are ruined by any defect in their institution, but generally by the corruption of manners; against which, the best institution is no long security, and without which, a very ill one may subsist and flourish.”

John Fletcher Moulton, a nineteenth-century English barrister, mathematician, and judge, observed that there exists a middle ground between the realm of the things we do with unrestricted freedom and those things we do because they are prescribed by law. He called this domain the “obedience to the unenforceable.” This is where our actions are influenced by a sense of what we view as good, moral, and proper—our unofficial code of duty to our families, friends, and fellow citizens and persons.

For Moulton, this code is where “the real greatness of a nation, its true civilization,” lies. The more society relies on self-regulation—and the less it relies on law, coercion, conflict, and litigation—the freer it is. The more people choose to respect and care for their fellow citizens and persons—especially the weak and the vulnerable—the more civilized they are. A free society depends on its citizens deciding to do the honorable and virtuous actions even when they have the opportunity not to do so. Moulton was neither the first nor the last thinker to make this observation.

Lord Kames reminded the young King George III in 1762 that “depravity of manners will render ineffectual the most salutary laws.” Montesquieu, among the most important intellectual influences on America’s Framers and founding, wrote that manners are those habits that are not established by legislators because they are unable to do so. He argued that wise and humble lawmakers must recognize that not everything can be corrected by law and policy, and that they should stick to their own lane: echoing John Locke, he wrote that while laws govern the body, custom governs the heart—the motivation, the disposition—of a citizen, and that a ruler had no business legislating matters of the heart. He argued that it is bad practice to try and change by law what should be changed by custom.

Ancient Roman society did not have a written constitution, and instead relied on standards of custom, morality, and manners that they called the mos maiorum—or the “old ways.” The old ways were an unwritten code of conduct, the lifeblood of the civic and moral norms that animated their republican system of government and allowed it to survive. As James Burgh, eighteenth-century English statesman, wrote in his 1774 Political Disquisitions, “Where the manners of a people are gone, laws are of no avail. They will refute them, or they will neglect them.”

In his second volume of The Civilizing Process, called Power and Civility, Norbert Elias argues that the increase of personal, individual constraints, between the period of the Middle Ages to the Renaissance and beyond, supported the liberal democratic project. A tightening of social norms and expectations—through peer-to-peer accountability at first, and later by government—contributed to the development of the modern nation-state. A country could grow only once there was domestic peace and the horizontal relationships between citizens were regulated. External controls of the state were supported by the individual citizen’s internal self-restraint—both of which are necessary for the liberal project.

Mos is etymologically related to our concept of “morality,” and also gives us our word “mores,” or social norms. Our own formal institutions also rely on unwritten rules and customs. Civility encompasses many of these unarticulated norms, and is essential to keeping governmental coercion from intervening in every social interaction.

Alexandra Hudson is an award-winning journalist, author, and speaker and the founder of Civic Renaissance, a newsletter dedicated to moral and cultural renewal. This article is adapted from her first book, The Soul of Civility: Timeless Principles to Heal Society and Ourselves, out now from St. Martin’s Press.

Image: William Hogarth, A Midnight Modern Conversation, ca. 1732 (Yale Center for British Art, Paul Mellon Collection/Wikimedia Commons)