The weakness of single-factor theories is also their virtue: they require us to consider phenomena that we might otherwise ignore or deprecate. The history of all hitherto existing societies is not the history of class struggle; the origins of China are not to be explained exclusively with reference to riparian infrastructure; and the development of American democracy is not solely the consequence of our frontier life. No complex movement or event can really be reduced to one driving force, but it is nonetheless instructive to view events through a single lens.

In that vein, tech engineer and independent researcher Jens Heycke asks us to understand the rise of the Roman Empire, the fall of the Ottomans, the Spanish conquest of Mexico, the Rwandan genocide, and sundry other events through the single lens of multiculturalism. Out of the Melting Pot, Into the Fire: Multiculturalism in the World’s Past and America’s Future is a call to revive a singular American identity. By “multiculturalism,” Heycke means extreme ethnic and cultural pluralism, in which various populations live side by side in a jumble without ever coming together around shared mores or traditions. He contrasts this approach with the “melting pot,” in which a strong sense of cultural unity smooths out the differences among new arrivals and assimilates them to the dominant local culture. America’s decline, Heycke argues, is the decline of the melting pot that made a polyglot mass of immigrants into Americans. He sees historical and contemporary precedents for America’s successes and failures in the cultural unity or fragmentation of other societies.


Heycke identifies the shared spirit of healthy societies with a principle that the 14th-century historian Ibn Khaldun called asabiyah—“social cohesion” or “group consciousness.” This is the “unifying feeling that binds a group together and makes collective action possible.” It engenders “the mutual affection and willingness to fight and die for each other.” Asabiyah is a fragile thing. Human beings are naturally disposed to “ethnic distinctions [that] divide people into groups that are reflexively distrustful and hostile toward each other,” Heycke warns. Even without ethnic distinctions, “they can seize on something superficial or trivial, like the preference for a sports team.” Social cohesion does not come naturally, he argues. It requires exhortation, education, and a foundation in common interests. Once lost, it spells doom for the society that has frittered it away.

The historical examples Heycke offers to support these central claims are less than convincing. In his telling, ancient Athens is supposed to have collapsed because “nearly a third of the population were metics—foreigners who had few rights and a vastly inferior status to ethnic Athenians…. In Rome, by contrast, even barbarians from beyond the [limites] could quickly become full citizens.” The devotion and loyalty inspired by this warm welcome made Roman armies more cohesive and resilient than their Athenian counterparts. In Heycke’s account, Rome “contrasted starkly with other classical civilizations in the degree of opportunity, meritocratic social mobility, and material comfort that it afforded people from very diverse racial and ethnic backgrounds.” The empire only began to fracture when the Romans shifted “from a ‘melting pot’ to a ‘multicultural’ system of managing its ethnic diversity.”


This seems too simple on several counts. For one thing, in the estimate of Cornell University classicist Barry Strauss, Athens fought the Peloponnesian War until 60% of its male citizen population had perished—a greater sacrifice than Rome ever made in its many wars. As for Rome’s own supposed social harmony, it was surely undercut by the fact that 20% or so of its population (as tallied by Columbia’s W.V. Harris) was enslaved. Slave labor on large plantations (latifundia) sustained its armies and urban population. Under Emperor Claudius, Rome had seven million citizens but 18 to 24 million slaves. In The Fall of Rome (2005), Oxford fellow Bryan Ward-Perkins argues that small barbarian populations succeeded in toppling Rome because slaves rose to join them.

Yet the Eastern branch of the Roman Empire endured for another thousand years after the city of Rome itself fell—Heycke does not pause to consider why that might have been, and what role Christianity might have played in preserving Byzantium. In fact, the term “Christianity” does not appear in his index. The index entry for “Islam,” by contrast, refers to 30 pages of text. Heycke writes:

The early Islamic ummah shared many characteristics with the Roman melting pot. Claudius and Cicero asserted that Rome’s continual assimilation of diverse populations and “adoption of even enemies as citizens” was one of the keys to its success. The early Islamic state embraced and followed this paradigm assiduously. Both the Qur’an and Muhammed’s policies established that it is best to welcome even former opponents into the ummah.

Islam appeared on the borders of the Byzantine Empire after a period of plague and economic collapse. Maya Shatzmiller, a medieval historian, observes that disease and dysfunction chased large portions of the population out of Mesopotamia: “[B]y 580 AD the size of the cultivated land began to shrink and by 628 AD at least half of the settled area was abandoned, with population numbers collapsing…. Archeological evidence from Egypt points to a similar situation there.” It remains a matter of controversy whether the migration from Arabia was accomplished chiefly by conquest or osmosis, and whether Islam as a religion inspired the conquest or rationalized it after the fact. Heycke claims that the “Islamic regime” treated Jews and Christians “as believers and did not persecute them over doctrinal niceties.” That is a controversial statement at best, in need of more support than a footnote referring to the 9th-century Persian historian al-Baladhuri. Other historians contend that the Muslim conquest produced depopulation and devastation.


Heycke’s survey continues through the genocide in Rwanda, a horrible testament to what can happen when colonial powers exploit ethnic divisions within conquered populations. In this case, a better policy might have averted the bloodbath. He also discusses communal violence between the Tamil and the Sinhalese in Sri Lanka, which he contrasts with the “tremendous communal harmony” between what he calls “the Chinese minority in Thailand” and the “ethnic Thai majority.” That is misleading because most Thais are ethnically Chinese, and immigrants from China adopted Thai names and language. It is impossible to distinguish “Thai Chinese” from “ethnic Thais” without knowing the history of the family in question.

For that matter, a cohesive Chinese civilization has persisted for thousands of years with seven major language groups and 200 dialects, unified by a common written language, a common system of administration, and the vast and costly riparian infrastructure required to sustain settlement on the enormous floodplain of the Yellow and Yangtze Rivers. Foreign invasions and natural disasters have broken China into competing provinces many times, but it has always reunified. In the 21st century it is stronger than ever before. Unlike Rome, a vast graveyard of tribes and languages, China for the most part has preserved its myriad of ethnicities and languages in amber. Rome’s economy depended on latifundia and slavery, while ancient China’s agriculture depended on the extended family farm. One wonders what Heycke would make of China’s singular form of asabiyah.

Without asabiyah, Heycke argues persuasively, societies fail. But what are the distinctive means by which unity can be fostered and maintained? Heycke does not have much to say about the unique nature of American identity, and Ibn Khaldun’s generic definition doesn’t explain why social cohesion persists in some civilizations but fails in others.

Christian Europe brokered a sort of dual citizenship: membership in the universal Church and Christian empire contended dynamically with national identity. Things fell apart in a sequence of cataclysms—the Thirty Years’ War, the Napoleonic Wars, and the two World Wars of the last century—that enervated the West. America emerged from this turmoil with a new model, offering a non-ethnic Christian form of civic unity. Even black Americans shared a deeply American identity through their churches, the defining institutions of black American life from before the civil rights era until just recently.


What changed, in Heycke’s view, was elite opinion: “In a few decades, the melting pot has gone from being celebrated as the key to America’s success to being dismissed as destructive and morally repugnant.” But that isn’t the whole story. It’s also true, and perhaps more consequential, that progressivism and the Social Gospel replaced the enthusiastic Protestantism of America’s founding. In the 1950s, two thirds of Americans professed Protestantism, compared to just one third today. Can America survive without the faith of its fathers?

Meanwhile, immigrants comprise just under 15% of the current U.S. population—up from 5% in 1970. One in five Americans speaks a language other than English at home. The total may be much higher depending on the true number of illegal immigrants, who by some measures amount to 22 million people. Although the proportion of immigrants is the same as in 1890, Heycke argues that “[t]he current migrant wave will change America’s ethnic composition far more profoundly than previous waves. In the big influx at the turn of the twentieth century, non-European immigrants accounted for only 3 percent of the total; today, they account for over 90 percent.”

That passing assertion could have used some qualification. Nearly a third of U.S. immigrants are Asian, the cohort with the highest economic achievement and a minimal crime rate—perhaps the most successful group of immigrants in American history. Whether Latin American immigrants will assimilate faster than Italians or Eastern Europeans remains to be seen. What has changed more than the character of the immigrants is that of the dominant culture: previously, new arrivals were invited into a robust social consensus informed by a vigorous Protestant majority. Now they are schooled in a post-Christian ideology of sex- and race-based hierarchy and grievance.


As Heycke observes, the term “melting pot” itself was made popular by Israel Zangwill’s 1908 play of the same name, in which a Jewish immigrant marries a Christian woman in a symbolic act of ethnic reconciliation. In fact, however, Jewish assimilation by intermarriage is a poignant expression of the general decline of American religion: as Rabbi Jonathan Sacks observed in The Home We Build Together (2007), Zangwill’s “real hope was for a world in which the entire lexicon of racial and religious difference is thrown away.”

That kind of assimilation, which smooths over even important differences in theological outlook, can end up dulling the passionate faiths whose energies kept America robust and thriving. Since the Puritan John Winthrop identified America as a “City Upon a Hill” in his 1630 sermon, American Protestantism has adopted the story of Israel as America’s own pre-history, and the continuing witness of observant Jews remains an inspiration for America’s religious identity. I doubt that Heycke had all this in mind, but the literary reference to Zangwill was ill-chosen as a model for American cultural cohesion. Our distinctive form of asabiyah is not served by melting down our various forms of worship into one vague, amorphous spiritualism.

Lack of a distinct national identity, of course, isn’t the only cause of societal decline. But no one will fight and die for his country without something that transcends the biological life of an individual. Whatever name we call it by—culture, tradition, or Sittlichkeit—this is what gives significance to our lives in the eyes of our countrymen when we are no longer alive. If we do not hear the same mystic chords of memory, then a nation is not a home but only a hotel full of strangers passing through.