The common consensus—outside academic circles, at least—is that the Aztec empire, like most indigenous American nations, crumbled under the combined force of colonial subjugation and imported European diseases. And while these factors certainly played substantial roles in the Spanish conquest of Mexico, another theory considers a fascinating aspect of Aztec society: human sacrifice.

And few things fascinate anthropologists and archaeologists, amateur and professional, than ritualistic slaughter. It can’t be helped. It’s the very same morbid appeal that HLN true-crime documentaries capitalize on. Death—the weirder, the better—is always enthralling.

For decades, historians were skeptical of Spanish accounts documenting Aztec human-sacrifice rituals. They were generally thought to be historiographical—intended to portray indigenous Mesoamericans as more savage than they actually were, thus necessitating “civilized” colonial governance. This was, after all, a common justification employed throughout the 500 or so years of European colonialism around the world.

But archaeological evidence suggests human sacrifice was indeed a regular aspect of Aztec religious practices. And the zeal with which it was practiced can be traced back to the political reforms of one man—imperial vizier Tlacaelel, who, in 1428, launched a campaign of religious codification, military development, and territorial expansion that would, for lack of a better term, really piss off the Aztec’s neighbors.

It all began with a restructuring of the Aztec pantheon. Tlacaelel elevated Huitzilopochtli, god of sun and war, to a Zeus-like position of preeminence—appropriate, considering the Aztecs’ push toward militarism at the time.

According to Aztec beliefs, Huitzilopochtli required regular nourishment (tlaxcaltiliztli) in the form of freshly harvested human hearts. As so-called “people of the sun,” the Aztecs were uniquely mandated to provide their patron deity with this bloody sustenance—more often than not sourced from people who were not “of the sun,” so to speak. It was a kind of cultural exceptionalism that not only lent the Aztecs an inherent, ethnic superiority, but directly victimized their neighbors, specifically the Tlaxcala people, who provided the lion’s share of sacrifice-able bodies for Aztec sun-god worship.

“[Tlacaelel’s] plan was to consolidate Aztec or Mexicatl grandeur,” says Antonio Serrato-Combe, a professor of archaeology at the University of Utah’s school of architecture, in an email to Quartz. Part of Tlacaelel’s reforms included expeditions into neighboring communities to “find individuals who were to be sacrificed,” he adds. “Obviously these communities were unhappy by the practice.”

This resentment, Serrato-Combe confirms, was fully exploited by Hernán Cortés.

Cortés, the notorious conquistador responsible for ultimately toppling the Aztec empire and bringing much of modern-day Mexico under Spanish control, forged an alliance with Tlaxcala and a few other neighboring groups in the early 16th century. Tlaxcala leaders quickly converted to Christianity, and provided 250,000 warriors to the siege of Tenochtitlan.

In a 2011 article written for History Today magazine, historian Tim Stanley wrote:

“[The Aztecs were] a culture obsessed with death: they believed that human sacrifice was the highest form of karmic healing. When the Great Pyramid of Tenochtitlan was consecrated in 1487 the Aztecs recorded that 84,000 people were slaughtered in four days. Self-sacrifice was common and individuals would pierce their ears, tongues and genitals to nourish the floors of temples with their blood. Unsurprisingly, there is evidence that Mexico was already suffering from a demographic crisis before the Spanish arrived.”

That number is disputed, however. Some say as few as 4,000 were sacrificed during what was actually a re-consecration of the Templo Mayor in 1487. Nevertheless, scores were killed. And perhaps there is some merit to the idea that, in obsessing over death and an imminent apocalypse, the Aztecs sealed their own fate.

The story of the rise and fall of the Aztecs highlights some intriguing problems with the ways we, in the post-Columbian Americas, attempt to understand our geographic predecessors. When speaking of Aztec sacrifice culture, many anthropologists are quick to resort to culturally relativistic justifications. Some insist only prisoners of war met these particularly gruesome fates, though archaeological findings suggest women and children were not entirely exempt from the practice.

This line of reasoning ultimately depicts Aztec customs as untouchable and requiring massive context. In doing so, it revives the trope of the “noble savage,” the idealized aborigine, whose manners and customs—in direct contradiction to colonialist rationalizations—were actually purer, less easily corruptible than those of the West.

There’s no use denying it: Aztec sacrifice was a bloody, messy, brutal affair. There was nothing noble about it.

And this means the Aztecs weren’t all that different from any other regionally dominant culture. They lived parasitically off of their weaker neighbors, just as the ancient Greeks and Romans, the Persians and Mongols, and the Vikings and Normans did. They engaged in what we, in the modern West, think to be crude or morbid practices—largely because they were—but which, outside of culturally specific contexts, differ little from the brutalities of Christian crusaders or Hunnish hordes. All of human history has been an exercise in human savagery. You could say the Aztecs, with their vividly violent codices, were just more honest and upfront about it.

Herein lies a majorpoint of contention among modern archaeologists and anthropologists. At one end of the spectrum, you have the fetishists: those who intensely scrutinize a single aspect of a given culture—usually its most obviously distinctive—and inflate it to the point of definitiveness. In this case, that the Aztecs sacrificed people, and were therefore a “death-obsessed” culture.

At the other end, you have the militant cultural relativists who, no matter how demonstrably unusual or violent a practice may be, conflate critical thinking with moralistic judgment, becoming rote collectors of archaeological information, if not unintentional perpetuators of the “noble savagery” stereotype.

The Aztecs are a fascinating civilization for many reasons, a taste for human sacrifice being unquestionably among them. Understanding them as a “death-obsessed” culture, as Mr. Stanely does, is objectifying. But framing sacrifice as nothing more than “delayed casualties of war” is similarly overly simplistic—politically correct to a fault. It denies the fact that sacrificial-worship culture was a component of Mesoamerican civilization at the time, and a distinctive one at that!

There’s a lot to learn from the Aztecs and neighboring cultures. It would be a shame to let those lessons go to waste—all because we’re too blinded by morbid curiosities, or overkill of academic methodologies. Instead, let’s allow ourselves to be truly, rightly fascinated.