Recent primaries have given Democrats reasons for hope, but they have also exposed fault lines within the party. Divisions are visible in the very labels used to describe them. Many use the word “liberal” as a catchall to describe left-of-center politics in general, but self-described leftists and members of the Democratic Socialists of America often characterize liberals and Democrats as their opponents—viewing them as the compromising centrists standing in the way of a more progressive or socialist agenda.

Many use “liberal” to describe left-of-center politics in general. But self-described leftists often see liberals as their opponents.

The language is telling. Some are “liberal Democrats,” others “establishment liberals.” Then there are “leftist” liberals and “progressive” ones. Alexandria Ocasio-Cortez, who ousted incumbent Joe Crowley in the Democratic primary for New York’s fourteenth congressional district, calls herself a “democratic socialist,” but she favors “progressive” policies. Andrew Gillum, by contrast, winner of the Democratic gubernatorial primary in Florida, favors a “progressive” platform, but categorically denies being a “socialist.” And Ayanna Pressley’s win in the seventh congressional district in Massachusetts has been described as the victory of an “unapologetic liberal” against the more “quiet” Michael Capuano—who is, nevertheless, “more liberal than Nancy Pelosi.”

Is this semantic murkiness a problem? Historian Sean Wilentz thinks it is, arguing recently in Democracy Journal that the confusion of terms reflects the “momentous muddle” in which Democrats find themselves. Too many liberals, Wilentz asserts, have lost sight of their own tradition. Liberalism, progressivism, and socialism are “plainly distinct” concepts with completely different histories—and only by coming to terms with this fact can liberals defend their true principles and win elections.

In reply, political scientist Jeffrey Isaac acknowledges that “words matter greatly in politics” but doubts that the answer lies in clarifying terminological distinctions. And, he says, Wilentz gets the history wrong: in fact, liberalism and socialism have never been irreconcilable. There has always been a “productive synergy” characterized by debate and dialogue; the answer to the present predicament is to rally against a common enemy and build bridges between the different ways of being liberal.

The histories of liberalism that we have—and which Wilentz exhorts us to return to—do little to resolve the muddle. In fact, they only further confound it. Some see liberalism originating in Christianity, others in a battle against it. Some think it stands for individual rights and freedoms, others for government intervention and the welfare state. Some conscript John Locke as a founding father; others look to Hobbes and Machiavelli, Plato or even Jesus Christ—even though none of these figures called themselves liberals or espoused anything called liberalism.

The trouble with the history of the idea avant la lettre is its plasticity: pick a different theory of liberalism, and you get a different view of its past. More revealing is a history of the word—where and when it has been used, by whom and to what ends. To fully understand how the language of liberalism became so confused, we must consider how it came to refer to a specifically American phenomenon.

Like much of our political vocabulary, the word “liberalism” emerged in the wake of the French Revolution. Coined in the early 1800s, it originally stood for a cluster of concepts including civic equality, constitutional and representative government, and a number of individual rights such as freedom of religion, property, and the press. But over the course of the nineteenth century, as a result of inequities generated by industrialized wealth, liberalism split in two. One branch advocated laissez-faire, often of a radical kind. Others, influenced by new ideas of political economy coming from Germany, advocated increasing government intervention to help the poor, calling themselves “social liberals” or “liberal socialists.” They saw no contradiction in this terminology; instead such ideas were thought to be the very expression of “true liberalism”—a common expression in the nineteenth century.

Pick a different theory of liberalism, and you get a different view of its past.

The word only came to the United States in the 1910s. According to the intellectual and political commentator Walter Lippmann, it acquired common currency thanks to a group of reformers who identified as Republican Progressives in 1912 and Wilsonian Democrats by around 1916. By then the term had evolved significantly from its century-long association with French political developments, and the ideas of German “ethical” economists such as Wilhelm Roscher, Bruno Hildebrand, and Karl Knies had made their mark—especially in England, where a “new liberalism” advocated for government intervention. Thanks largely to the travails of the British Liberal Party, liberal newspapers, and liberal theorists such as Leonard Hobhouse, this new form of liberalism spread, and by the second decade of the twentieth century, its advocates felt secure enough to drop the “new” and just call it liberalism. It was this liberalism that was imported into the United States after the war: Woodrow Wilson called himself progressive in 1916, but by 1917 he was a liberal.

Herbert Croly, one of the most influential public intellectuals of the Progressive movement and cofounder of the flagship progressive magazine the New Republic in 1914, helped disseminate the term. His enormously influential book, The Promise of American Life (1909), delivered a stinging indictment of laissez-faire economics and a strong argument for government intervention. It is more than likely that Croly adopted the term to show solidarity with the liberal government and liberal thinkers in Britain, with whom he clearly sympathized. By 1914 Croly had begun calling his own ideas liberal, and by mid-1916 the term was in common use in the New Republic simply as another way to describe progressive legislation. After all, as Woodrow Wilson explained in his Constitutional Government in the United States in 1908, Americans “borrowed our whole political language from England.”

President Wilson may also have been one of the first Americans to use the word “liberal” to describe a certain foreign policy agenda. During his Peace without Victory address in January 1917, he claimed to be “speaking for liberals and friends of humanity.” While en route to the Paris Peace conference to sell his Fourteen Points, he declared that “liberalism is the only thing that can save civilization from chaos.”

Liberalism had always been about more than domestic politics, of course. From the French military officer Lafayette, who boasted that liberalism was a vast movement radiating outward from France, to the conservatives who feared a “universal liberalism” with reverberations as far away as India, the idea of spreading liberalism internationally had a long history. On his way to Paris, Wilson visited Genoa and paid tribute to the monument of Italian revolutionary Giuseppe Mazzini, who championed Italian independence and unification. Wilson claimed that he had studied Mazzini’s writings closely and had derived guidance from them, adding that with the end of the war, he hoped to contribute to “the realization of the ideals to which his [Mazzini’s] life and thought were devoted.”

To understand how the language of liberalism became so confused, we must consider how it came to refer to a specifically American phenomenon.

Wilson surely knew that liberalism was closely intertwined with the idea of empire. Many of the British liberals U.S. progressives looked to spoke of empire as a way of spreading liberal values around the world. Some saw no contradiction in believing simultaneously that “the root principle of liberalism” is a “passionate attachment to the ideal of self-government” and that empire was a “truly liberal foreign policy” that would spread civilization and the “arts of government” around the world. As has now been well-studied, this pro-colonial liberal discourse was saturated with racist language: references to the “lower races,” “subject races,” and “barbarian races” abound. And although the purpose of “genuine colonialism”—as its advocates called it—was ostensibly to promote their self-government, how long such lower races should expect to wait until they were permitted to govern themselves was often left vague. It depended on the level of their social development, how far they had been “civilized.” “A barbarian race may prosper best,” British Liberal Party leader Herbert Samuel wrote, “if for a period, even for a long period, it surrenders the right of self-government in exchange for the teachings of civilization.”

As World War I approached, U.S. and British liberals increasingly felt the need to distinguish themselves and their political traditions from Germany. In a series of essays for the New Republic in 1915, the Spanish American philosopher and essayist George Santayana expounded on liberalism and the differences between the British and German notions of freedom. England, he wrote, had parliamentary government, whereas Germany had an authoritarian bureaucracy. The German government dictated how individuals should behave toward one another, while in Britain individuals were free to make their own decisions.

This willful disassociation with Germany was of course only magnified by the war, as anti-German hostility grew. Germany’s contribution to the history of liberalism was thus progressively forgotten or pushed aside while the sense of an Anglo-American alliance grew, and soon the French contribution would be minimized too. Meanwhile “liberalism,” “democracy,” and “Western civilization” became virtually synonymous, and the United States, because of its growing power, was cast as their principal representative and defender. The equation was solidified and disseminated through Western civilization courses that were invented after the war and taught on U.S. college campuses to explain what the country had fought for. Still, it was only in the late 1930s that liberalism as a political philosophy began to appear in U.S. textbooks. George Sabine’s A History of Political Theory, used in most U.S. undergraduate and graduate programs at the time, was the first major textbook to discuss it.

During the 1920s and 1930s, European fascists and Nazis took this equation for granted, and they defined themselves in opposition to it. Prominent German intellectuals, including Oswald Spengler, Friedrich Junger, Carl Schmitt, and Moeller van den Bruck, denounced liberalism as a foreign philosophy and the very antithesis of German culture. Liberalism, they said, was Germany’s archenemy, which is why the patron saint of National Socialism Moeller van den Bruck so happily claimed, incorrectly of course, that “there are no liberals in Germany today.” It is also why the Italian dictator Benito Mussolini held up fascism as the very “negation” of liberalism, while Adolf Hitler declared that the chief goal of Nazism was “to abolish the liberalistic concept of the individual.” The claim that liberalism was un-French and un-German was forcefully refuted by the antifascist Italian writer Guido de Ruggiero in his History of European Liberalism of 1925. The crisis of liberalism, Ruggiero asserted, should not be taken to mean that there was no European liberal tradition; while he admitted the importance of the “Anglo-Saxon” version, he devoted a chapter each to Italian, English, German, and French liberalism.

From the growing association of liberalism with the United States—which would only continue during World War II—it would be wrong to conclude that there was a consensus over what the word meant: how, for example, liberalism differed from democracy, or what it meant in terms of a government’s role in the economy. While the progressives around the New Republic called themselves liberal, Herbert Hoover did too, sounding a lot like the nineteenth-century British philosopher Herbert Spencer, who advocated an extreme variety of laissez-faire. Hoover insisted that liberalism’s main concern was the protection of individual freedom; it stood for the idea that government should involve itself as little as possible in the economy. As president, he oversaw the stock market crash of 1929 and the onset of the Great Depression, yet he continued to defend the laissez-faire version of liberalism well into the 1940s.

The word “liberalism” emerged in the wake of the French Revolution; it came to the United States only in the 1910s.

In continental Europe, powerful voices also spread the idea that liberalism meant laissez-faire, arguing that those who meant something else by the term had to add a qualifier such as “progressive” or “constructive” or speak of “liberal socialism.” In Liberalism (1927), the influential Austrian economist Ludwig von Mises lamented these semantic disputes. True liberalism, he insisted, was not about humanitarian objectives, however noble they might be. Liberalism had nothing else in mind than the advancement of a people’s material welfare. Its central concepts were private property, first, and then freedom and peace. Anything beyond that was “socialism,” for which Mises had only disdain. Those who thought that liberalism had something to do with spreading humanity and magnanimity were “pseudo liberals.”

Soon, however, the American philosopher John Dewey would make a herculean effort to seal the progressive meaning of the word once and for all. Dewey received his PhD in 1884 at Johns Hopkins, where he took classes with the economist and Progressive leader Richard Ely, who had imbibed the new ideas coming from Germany. In 1914 Dewey became a regular contributor to the progressive-dominated New Republic. Over the course of his long career, he published over forty books and several hundred essays—including, in the 1930s, titles such as “The Meaning of Liberalism,” “The Meaning of the Term: Liberalism,” “A Liberal Speaks Out for Liberalism,” “Liberalism and Civil Liberties,” and Liberalism and Social Action (1935).

Throughout these works, Dewey explained that there were “two streams” of liberalism. One was more humanitarian and therefore open to government intervention and social legislation. The other was beholden to big industry, banking, and commerce and was therefore committed to laissez-faire. American liberalism, he insisted, had nothing to do with laissez-faire, and never had, nor did it have anything to do with the “gospel of individualism.” Instead it stood for “liberality and generosity, especially of mind and character,” and its aim was to promote greater equality and combat plutocracy with the aid of government.

The person most responsible for making this meaning of liberalism dominant in the United States was Franklin Delano Roosevelt. Like so many liberals before him, Roosevelt claimed the moral high ground for liberalism: liberals, he said, believed in generosity and social mindedness. They were willing to sacrifice for the public good. Over the course of his years in office, Roosevelt spoke often of the importance of human cooperation: “the faith of a liberal,” he said, “was the belief in the effectiveness of people helping one another.”

Roosevelt also solidified a link between liberalism and the Democratic Party that endures to this day. The “liberal party,” he said, believes that “as new conditions and problems arise beyond the power of men and women to meet as individuals, it becomes the duty of the government itself to find new remedies with which to meet them . . . the conservative party . . . believes the contrary—that there is no necessity for the Government to step in.” To emphasize the point, in his speech nominating Roosevelt as the Democratic candidate for the presidency in 1944, Henry Agard Wallace, who served as vice president, secretary of commerce, and then editor of the New Republic, used the word “liberal” no fewer than fifteen times, in one instance calling the president the “greatest liberal in the history of the United States.”

Roosevelt’s meaning of the word was close to that of the British economist, social reformer, and member of the Liberal Party William Beveridge. His Report of 1942 served as the basis for the post–World War II British welfare state. In a 1945 pamphlet titled Why I Am a Liberal, Beveridge declared, “Liberty means more than freedom from the arbitrary power of governments. It means freedom from economic servitude to want and squalor and other social evils; it means freedom from arbitrary power in any form. A starving man is not free.”

Meanwhile the Austrian-born economist Friedrich Hayek, a disciple of Mises, vehemently contested Beveridge’s and Roosevelt’s use of the word. In 1931 he joined the London School of Economics, where he became a virulent critic of FDR-style liberalism and the New Deal. Horrified by political developments on the European continent, he warned that embarking on “collectivist experiments” would put countries on a slippery slope to fascism; it was necessary, therefore, to return to “the old liberalism,” which meant government nonintervention. His position only grew more insistent and radical with time.

Liberals have always been known by different names as they responded to new political and social circumstances.

Hayek published the bestselling Road to Serfdom in 1944. “It is necessary,” he wrote in an impassioned introduction, “to state the unpalatable truth that it is Germany whose fate we are in some danger of repeating.” On this view, liberal socialism was a contradiction in terms. The role of government was not to be kind or generous but to protect the freedom of the individual. Western civilization was “an individualist civilisation.” True liberal principles derived from the ideas of English individualism. Liberal socialism, on the other hand, was a German import, stemming from the ideas of Bismarck’s advisors, and was a danger to Western civilization. It would invariably lead to “serfdom” and “totalitarianism,” a relatively new word at the time.

Despite such efforts, only two years later Hoover acknowledged defeat. With discernible bitterness, he conceded: “We do not use the word ‘liberal.’ The word has been polluted. . . . Liberalism was founded to further more liberty for men, not less freedom. Therefore, it was militant against the expansion of bureaucracy, against socialism and all of its ilk.” Similarly, in a 1948 speech titled “What Is a Liberal?,” Republican Senator Robert Taft complained that a word “which used to be a sound Anglo-Saxon word with a clear meaning, has lost all significance.” Contrary to the administration’s use, “the word ‘liberal’ in the political sense certainly does not connote ‘generous.’” The “basic meaning” remained pure and simple: “someone in favor of freedom.” Hayek eventually gave up on the word too. In 1950, he moved to the University of Chicago, where he accepted a position as professor in the Committee on Social Thought. There he inspired, among others, the U.S. economist Milton Friedman and eventually became a favorite of those we now call libertarians. To this day, many of his followers claim that they are the true—“classical” or “orthodox”—liberals, and Hayek himself has adopted at various points the label of a “consistent liberal,” a “neoliberal,” or a “radical.”

By mid-century, both versions of liberalism—Dewey’s as well as Hayek’s—had, for better or worse, become “the American creed.” As Lionel Trilling remarked in the preface to The Liberal Imagination (1950), liberalism in the United States had become “not only the dominant but even the sole intellectual tradition.”

From the beginning, liberalism was a highly contentious concept. As they do today, its critics claimed that it destroyed religion, the family, and the community: it was morally lax and hedonistic. Defenders were just as emphatic; to them it stood for freedom, equality, and the public good. But liberals often disagreed about how to translate these principles into practice. How broad should the franchise be? Which freedoms should be guaranteed? And what should the role of government be in the economy?

The predicament faced by today’s Democrats is therefore not a new one. History tells us that liberals have always been known by different names as they responded to new political and social circumstances. Some have called themselves “progressive,” while others have preferred “socialist.” The boundaries between these terms have been porous, their meanings changeable. If there is a moral to be drawn from this history, it is that even where they argued over the meaning of “true liberalism,” liberals were strongest when they found common ground—especially in the face of authoritarian rulers and demagogues. The 2018 U.S. midterm elections will put that pattern to the test once again.