This month marks the 200th anniversary of one of the most significant statements of the principles of liberalism: Benjamin Constant’s 1819 lecture on “The liberty of the ancients compared with that of the moderns.” The ancient Greeks, Constant said, believed that liberty consisted of public democratic control, the right to take part in shared political decisions shaping collective life. This conception of liberty had animated not only the thought of some 18th-century theorists such as Jean-Jacques Rousseau, but also much of the ideology of the French Revolution. But in modern times it is anachronistic and doomed to failure. Modern liberty is the liberty of diverse people pursuing their various, different private lives: their different trades and professions, their different recreations and consumption, their different ideas, and their different religious faiths. Ancient liberty was premised on slavery, to free up the time of citizens to go take part in the assemblies; on small political societies, where one person’s voice and vote could make a meaningful difference; on near-constant war, to preserve those small societies in their independence; and on a balance between public goods and private deprivation (notice that those have the same root) that favored the former. We moderns are different in each respect. We have rejected slavery (by 1819 this was true in WesternEurope, though of course not in the United States). We live in such large societies that the effective value of one person’s share of control over public life is infinitesimal. Commerce has replaced war as the fundamental kind of international relationship. And our private lives are richer with options and possibilities. And so we moderns will not be satisfied with ancient liberty that prioritizes our share of collective power. We will insist on the modern liberty of determining our individual lives.

Constant was born a Swiss Protestant, was educated in Scotland when the intellectual influence of David Hume and Adam Smith was still large, took part in the politics of the French Revolution,and later in life spent time with the early leading lights of German romanticism. His mature thought wove together ideas from across the late 18th- and early 19th-century European landscape into a distinctive synthesis: an idiosyncratic philosophy of religion, a romantic sensibility about individual sentiments and distinctiveness, and a forceful commitment to what we now recognize as the political core of liberalism: freedom of speech, the press, association, and religion;commercial liberty; equality before the law; and the rule of law with robust procedural protections and civil liberties. After spending much of the Napoleonic era in exile as an opponent of Bonapartism, and a brief,ill-fated attempt to convert Napoleon to liberal constitutionalism during the latter’s return to power in the Hundred Days, he spent the Bourbon Restoration as a member of parliament and an intellectual leader of what emerged as its liberal bloc, one of the first political groupings to identify with that word. He was the first great political thinker to go by “liberal” as a label, and he shaped what that concept meant for a generation or more, not only in France but across Europe and Latin America. And he contributed a great deal to what became known as the idea of “responsible government” in parliamentary democracies, the idea that the executive cabinet of ministers was responsible to and chosen by parliament rather than the king. This in turn means that he understood, as the American founders a generation before had not, that representative government had to be pluralistic and partisan, with a majority that supported the ministers and a minority that opposed and questioned them.

The lecture on ancient and modern liberty was a piece of his long-term campaign to provide an education in what he called “constitutional politics” to the French people. Content neither to write only for scholarly readers nor to engage in political struggle only with other politicians, he hoped to build the support for liberalism in public opinion that would be needed to end the country’s swings between revolution and absolutism. (To that degree, my colleague Aurelian Craiutu is right to claim Constant as a moderate.)

It is an elegant and erudite piece of writing, a distillation of decades of Constant’s thought in a form that was meant to be accessible to ordinary listeners who had lived through the tumult of the Revolution and the Empire. It is a bit of a shame that it has overshadowed his intellectually vital full-length works in political and constitutional theory, but it deserves its fame. Its celebration of modern liberty is recognizably the whole core of the liberal vision, in a way that neither Locke’s theory of property ownership, nor Montesquieu’s account of judicial protections, nor Publius’ defense of representative constitutionalism is— to say nothing of the narrow utilitarianism that by Constant’s time was coming to dominate pro-market thought in England. And of course each piece of that vision remains in need of reiteration and defense on an ongoing basis. Neither freedom of international trade nor liberty of religion can be taken for granted.

Constant’s rejoinder to Rousseau’s, Mably’s, and the Jacobins’ obsession with the unified democratic people is of equally enduring importance. The aspiration of the believers in ancient liberty to have a unified, homogeneous, singular people rule, ignoring the pluralism and disagreement at the heart of political life, lives on in the populist contempt for partisan competition. The nationalist belief that a people or nation is free only if it is fully sovereign, and that this collective freedom to (say) restrict trade and migration is more important than the actual liberty of persons to trade or migrate, is a descendant of the same pathology. Constant notes that the desire to have national religious homogeneity and to keep foreign faiths away is a conservative version of the Jacobins’ mistake, and that,too,is a desire that afflicts our politics to this day.

Constant’s vision of liberalism and his critique of an anachronistic, anti-pluralistic, illiberal understanding of democracy both stand the test of time and repay rereading today. But contemporary readers who are used to the idea of conflicts between liberalism and democracy, used to civil-libertarian liberals who emphasize strong courts and market liberals who critique the incompetence of democratic voters, will be surprised at the rousing defense of (representative, electoral) democracy that concludes the lecture.

Constant warns that the very richness of our modern private lives would lead moderns to neglect what was vital in the liberty of the ancients. Wrapped up in our private lives, we would find democratic politics too burdensome and time-consuming; anxious to protect what is ours, we would find elections too unpredictable. And so we— by whom he meant, especially, the commercial and propertied middle classes— will easily be tempted by the Bonapartist offer: I will take the trouble of governing off your hands and protect you from unpredictable political give-and-take. Constant was sure that such offers are made in bad faith, and that they would represent a bad exchange even if they were not; they end with even our private,modern liberty being at the mercy of strongmen and dictators. But this wouldn’t make us immune to the temptation.

He worried, in short, that moderns, and particularly the middle-class and wealthy liberals worried about protecting what they own,would not be committed enough democrats to make good liberals. For all the transformations of modernity, the regime of religious liberty and free speech, commercial liberty and free trade, and the rule of general law with protection against arbitrary punishment could never be taken for granted. It could always be politically undone. All our modern goods are vulnerable to bad politics, and they are only secure if we secure them with better politics, which requires that we engage with democratic life rather than retreating to the private economy.

And this, too, is an enduring fact, one I will consider in tomorrow’s essay on democracy for Republicans.