The pluralistic defense of cultural diversity typical of Vico, Herder, and James has grown more powerful in the modern world as ethnic and racial groups within multiethnic societies have increasingly sought to exercise political power and retain their cultural heritage in the face of demands for cultural conformity. In the United States the pragmatists Horace Meyer Kallen (1882–1974) and Randolph Silliman Bourne (1886–1918) supplied a spirited defense of diversity during World War I. Although the American political tradition of classical liberalism championed individual rights, it failed to extend those rights to include the right to be culturally different. Liberal rights had wrongly assumed "that men are men merely, as like as marbles and destined under uniformity of conditions to uniformity of spirit," Kallen wrote in "Democracy versus the Melting Pot" (p. 193). The right to cultural identity was essential to selfhood, however, and Kallen called for a "Federal republic," a "democracy of nationalities, cooperating voluntarily and autonomously in the enterprise of self-realization through the perfection of men according to their kind" (p. 220).
Similarly Bourne's 1916 essay "Transnational America" reminded dominant Anglo-Saxons that even the early colonists "did not come to be assimilated in an American melting-pot. They did not come to adopt the culture of the American Indian" (p. 249). Bourne also called for a "cosmopolitan federation of national colonies" within which ethnic groups "merge but they do not fuse" (pp. 258, 255). Thus an immigrant would be both a Serb and an American, for example, as difference harmonized with common ground.
Although both men challenged what was taken by most Anglo-Saxons to be the absolute truth regarding what it meant to be an American, Bourne went well beyond Kallen's demand for freedom defined simply as a private right to be different. Influenced by the Enlightenment, Kallen assigned ethnicity to private life while he placed the public world in the hands of technical experts. Bourne, on the other hand, urged a national collaboration in the construction of a new national culture by all racial and ethnic groups in terms reminiscent of Herder. Contrarily then, Bourne's freedom meant "a democratic cooperation in determining the ideals and purposes and industrial and social institutions of a country" (p. 252). Thus while Kallen's vision served to strengthen the dominance of experts in the public sphere of work and politics, Bourne called for a "Beloved Community" that placed democratic participation and a discussion of values at the very center of public life (p. 264).
Animated by these somewhat contradictory ideals, cultural pluralism constituted a protean movement in the first half of the twentieth century in the United States. Particularly important achievements include the efforts of John Collier (1884–1968) as commissioner of Indian Affairs during the administration of Franklin Roosevelt to overturn the U.S. government's policy of assimilation of the American Indian. Due to Collier's efforts, Native Americans regained the right to their cultures, lands, and tribal political institutions after decades of denial. The Harlem Renaissance of the 1920s also reflected the principles of cultural pluralism. Alain Leroy Locke (1886–1954), America's first African-American Rhodes scholar and a former student of William James, furnished the guiding vision of the Renaissance and helped to achieve Bourne's "beloved community." Finding beauty within himself, through a rebirth of black art, the "new Negro" would thereby achieve the moral dignity suited to a "collaborator and participant in American civilization" (Locke, 1925, p. 5). Langston Hughes, Zora Neale Hurston, Claude Mackay, Jean Toomer, and others awakened black pride and offered an aesthetically and spiritually barren industrial capitalist America African-American wisdom and beauty instead of the ashes of materialism.
During the second half of the twentieth century, cultural pluralist thought in the United States was increasingly eclipsed by the lingering commitment of liberal intellectuals to the Marxist notion of culture as mere superstructure or as determined by the more fundamental struggle for power. Nevertheless, minority groups continue to struggle to achieve cultural democracy in the early twenty-first century's multicultural societies. As the Canadian philosopher Charles Taylor, following Herder, has argued, being true to oneself requires an acknowledgment by both self and other of the indispensable role of culture in the creation of identity. Because culture imparts those particular aspects—religion, language, traditions—that make an individual or group unique, the forced assimilation of minorities to the hegemonic standard of identity by a majority group constitutes a form of oppression and violence of the spirit. This recognition has led in turn to efforts to expand the political theory of liberalism to include not only a defense of identical universal rights but the right of groups to cultural differences as well. Cultural pluralists therefore seek to supplant cultural monism or absolutism with pluralism by reconciling community with diversity in the modern world.
Critics of cultural pluralism and multiculturalism worry, however, that the twenty-first century's emphasis on racial, ethnic, and cultural diversity will go too far and erode the common ground necessary to national unity. Arthur M. Schlesinger Jr., for example, decried the collapse of shared values and traditions under the weight of a dangerous tribalism in The Disuniting of America. Assimilation within the crucible of the melting pot, America's "brilliant solution for the inherent fragility of a multicultural society," was being destroyed by the multiculturalists' "search for roots" and the "cult of ethnicity" (Schlesinger, pp. 13, 15). Thus unity threatened to "give way to the Tower of Babel" (Schlesinger, p. 17).
David Hollinger has similarly pointed out the dangers of diversity. Unlike Schlesinger's prescription for a conformist unity based on assimilation, however, Hollinger has called for a postethnic America founded upon cosmopolitanism. Drawing a helpful distinction between cosmopolitanism and conformist universalism, he argued that the former "shared with all varieties of universalism a profound suspicion of enclosures, but cosmopolitanism is defined by an additional element not essential to universalism itself: recognition, acceptance, and eager exploration of diversity" (p. 84). At their best, such critics remind us that the claims of diversity and community must be reconciled, a reconciliation achieved by the civil rights movement of the 1950s and 1960s.