Human sacrifice was a religious practice of the pre-Columbian Aztec civilization, as well as other Mesoamerican civilizations such as the Maya and the Zapotec. The extent of such practices is debated by modern scholars.
- The antecedents of Mesoamerican sacrifice
- The role of sacrifice in Mesoamerica
- The 52 year cycle
- Xipe Totec
- The Flower Wars
- The sacrifice ritual
- Estimates of the scope of the sacrifices
- Assessment of the practice of human sacrifice
- The ecological explanation
- The political explanation
- The psychological explanation
- See also
Spanish explorers, soldiers and clergy who had contact with the Aztecs between 1517, when an expedition from Cuba first explored the Yucatan, and 1521, when Hernán Cortés conquered the Aztec capital of Tenochtitlan, made observations of and wrote reports about the practice of human sacrifice. For example, Bernal Díaz's The Conquest of New Spain includes eyewitness accounts of human sacrifices, as well as descriptions of the remains of sacrificial victims. In addition, there are a number of second-hand accounts of human sacrifices written by Spanish friars, that relate the testimony of native eyewitnesses. The literary accounts have been supported by archeological research. Since the late 1970s, excavations of the offerings in the Great Pyramid of Tenochtitlan, Teotihuacán's Pyramid of the Moon, and other archaeological sites, have provided physical evidence of human sacrifice among the Mesoamerican peoples.
A wide variety of explanations and interpretations of the Aztec practice of human sacrifice have been proposed by modern scholars. Most scholars of Pre-Columbian civilization see human sacrifice among the Aztecs as a part of the long cultural tradition of human sacrifice in Mesoamerica.
The antecedents of Mesoamerican sacrifice
The practice of human sacrifice was widespread in the Mesoamerican and in the South American cultures during the Inca Empire. Like all other known pre-Columbian civilizations of Mesoamerica, the Aztecs practiced human sacrifice. The extant sources describe how the Aztecs sacrificed human victims on each of their eighteen festivities, one festivity for each of their 20-day months. It is unknown if the Aztecs engaged in human sacrifice before they reached the Anahuac valley and started absorbing other cultural influences. The first human sacrifice reported in the sources was the sacrifice and skinning of the daughter of the king Cóxcox of Culhuacán; this story is a part of the legend of the foundation of Tenochtitlan. Several ethnohistorical sources state that under the guidance of Tlacaelel, the importance of human sacrifice in Aztec history grew. The Aztecs would perform a series of rituals on nearby tribesmen, sacrifice them using an obsidian knife, and then donate their blood to the Aztec god Acolnahuacatl. They would end the sacrificing when he had finished drinking and he was no longer thirsty. This ritual would go on for a whole weekend so as to please the gods.
The role of sacrifice in Mesoamerica
Sacrifice was a common theme in Mesoamerican cultures. In the Aztec "Legend of the Five Suns", all the gods sacrificed themselves so that mankind could live. Some years after the Spanish conquest of Mexico, a body of Franciscans confronted the remaining Aztec priesthood and demanded, under threat of death, that they desist from this traditional practice. The Aztec priests defended themselves as follows:
Life is because of the gods; with their sacrifice they gave us life.... They produce our sustenance... which nourishes life.
What the Aztec priests were referring to was a central Mesoamerican belief: that a great, continuing sacrifice of the gods sustains the Universe. Everything on earth is tonacayotl—"spiritual flesh-hood". All things—earth, crops, moon, stars and people—spring from the severed or buried bodies, fingers, blood or the heads of the sacrificed gods. Humanity itself is macehualli, "those deserved and brought back to life through penance". A strong sense of indebtedness was connected with this worldview. Indeed, nextlahualli (debt-payment) was a commonly used metaphor for human sacrifice, and, as Bernardino de Sahagún reported, it was said that the victim was someone who "gave his service".
Human sacrifice was in this sense the highest level of an entire panoply of offerings through which the Aztecs sought to repay their debt to the gods. Both Sahagún and Toribio de Benavente (also called "Motolinía") observed that the Aztecs gladly parted with everything: burying, smashing, sinking, slaying vast quantities of quail, rabbits, dogs, feathers, flowers, insects, beans, grains, paper, rubber and treasures as sacrifices. Even the "stage" for human sacrifice, the massive temple-pyramids, was an offering mound: crammed with treasures, grains, soil and human and animal sacrifices that were buried as gifts to the deities. Adorned with the land's finest art, treasure and victims, these temples became buried offerings under new structures every half a century.
The sacrifice of animals was a common practice, for which the Aztecs bred dogs, eagles, jaguars and deer. Objects also were sacrificed by being broken and offered to the gods. The cult of Quetzalcoatl required the sacrifice of butterflies and hummingbirds.
Self-sacrifice was also quite common; people would offer maguey thorns, tainted with their own blood and, like the Maya kings, would offer blood from their tongues, ear lobes, or genitals. Blood held a central place in Mesoamerican cultures. The 16th-century Florentine Codex by Franciscan friar Bernardino de Sahagún reports that in one of the creation myths, Quetzalcóatl offered blood extracted from a wound in his own genitals to give life to humanity. There are several other myths in which Nahua gods offer their blood to help humanity.
Much like the role of sacrifice elsewhere in the world, it thus seems that these rites functioned as a type of atonement for Aztec believers. According to the Dominican friar Diego Durán (c. 1537–1588), their sacrificial hymns describe the victim as "sent (to death) to plead for us", or "consecrated to annul all sin". In one such poem, a warrior-victim announces that "I embrace mankind... I give myself to the community". Aztec society viewed even the slightest tlatlacolli ('sin' or 'insult') as an extremely malevolent supernatural force. For instance, if an adulterer were to enter a house, it was believed that all turkey chicks would perish from tlazomiquiztli ("filth-death"). To avoid such calamities befalling their community, those who had erred punished themselves by extreme measures such as slitting their tongues for vices of speech or their ears for vices of listening, and "for a slight [sin they] hanged themselves, or threw themselves down precipices, or put an end to themselves by abstinence".
A great deal of cosmological thought seems to have underlain each of the Aztec sacrificial rites. The most common form of human sacrifice was heart-extraction. The Aztec believed that the heart (tona) was both the seat of the individual and a fragment of the Sun's heat (istli). To this day, the Nahua consider the Sun to be a heart-soul (tona-tiuh): "round, hot, pulsating". In the Aztec view, humanity's "divine sun fragments" were considered "entrapped" by the body and its desires:
It also seems that at least in some cases, the strong emphasis given to human sacrifice may have stemmed from the great honour Mesoamerican society bestowed on those who became an ixiptla—that is, a god's representative, image or idol. Ixiptla was the same term used for wooden, stone and dough images of gods. Interestingly, Aztec texts rarely differentiate between human ixiptla and wooden or stone ixiptla. Both types were so elaborately costumed and painted that even the congregation was unsure which were human ixiptla and which were stone or wood (Duran, Book of the Gods and Rites, 102). Thus, when a victim appeared in full regalia before the congregation, it was said that the divinity had been given 'human form'—that the god now had an ixitli (face) (Duran, Book of the Gods..., 72-73). Duran says such victims were 'worshipped... as the deity' (Duran, Book of the Gods and Rites, 42,109,232) or 'as though they had been gods' (Sahagun, Florentine Codex Bk 2: 226, 238-239) (-the original Nahuatl term being nienoteoti'tzinea, literally, 'I consider him a god') (Clavigero, 98). Even whilst still alive, ixiptla victims were honoured, hallowed and addressed (like gods) as 'Lord' and 'Lady' (Duran, Book of the Gods and Rites.., 189). Posthumously, their remains were treated as actual relics of the gods which explains why victims' skulls, bones and skin were often painted, bleached, stored and displayed, or else used as ritual masks and oracles. For example, Diego Duran's informants told him that whoever wore the skin of the victim who had portrayed god Xipe (Our Lord the Flayed One) felt he was wearing a holy relic. He considered himself 'divine' (Duran, Book of the Gods and Rites..176).
Finally, according to the Aztec (and Mesoamerican) world-view, the circumstances in which people died determined the type of afterlife they enjoyed. The Aztecs had meticulously organised death into several types, which each led to specific "heavenly" and "underworld" levels. In the levels Sahagun records, passing away quietly at home was the lowest, as it required the unfortunate soul to undergo numerous torturous trials and journeys, only to culminate in a sombre underworld. By contrast, what the Aztecs termed "a good death" was sacrifice, war (which usually meant sacrifice) or—in the case of women—death whilst giving birth. This kind of end procured for the deceased the second-highest heaven (death in infancy being the highest). Persons who had died sacrificially or in war were called Teo-micqui ("the God-dead") and were said to "go pure... live hard by, nigh unto the Sun... [who] always forever ... rejoice ... [since] the House of the Sun is ... a place of joy."
The 52-year cycle
The cycle of fifty-two years was central to Mesoamerican cultures. The Nahua's religious beliefs were based on a great fear that the universe would collapse after each cycle if the gods were not strong enough. Every fifty-two years a special New Fire ceremony was performed. All fires were extinguished and at midnight a human sacrifice was made. The Aztecs then waited for the dawn. If the Sun appeared it meant that the sacrifices for this cycle had been enough. A fire was ignited on the body of a victim, and this new fire was taken to every house, city and town. Rejoicing was general: a new cycle of fifty-two years was beginning, and the end of the world had been postponed, at least for another 52-year cycle.
Huitzilopochtli was the tribal deity of the Mexica and, as such, he represented the character of the Mexican people and was often identified with the sun at the zenith, and with warfare, who burned down towns and carried a fire-breathing dragon or serpent. He was considered the primary god of the south and a manifestation of the sun, and a counterpart of the black Tezcatlipoca, the primary god of the north, "a domain associated with Mictlan, the underworld of the dead."
When the Aztecs sacrificed people to Huitzilopochtli (the god with warlike aspects) the victim would be placed on a sacrificial stone. The priest would then cut through the abdomen with an obsidian or flint blade. The heart would be torn out still beating and held towards the sky in honor to the Sun-God; the body would be carried away and either cremated or given to the warrior responsible for the capture of the victim. He would either cut the body in pieces and send them to important people as an offering, or use the pieces for ritual cannibalism. The warrior would thus ascend one step in the hierarchy of the Aztec social classes, a system that rewarded successful warriors.
Tezcatlipoca was generally considered the most powerful god, the god of night, sorcery and destiny (the name tezcatlipoca means "smoking mirror", or "obsidian"), and the god of the north. The Aztecs believed that Tezcatlipoca created war to provide food and drink to the gods. Tezcatlipoca was known by several epithets including "the Enemy" and "the Enemy of Both Sides", which stress his affinity for discord. He was also deemed the enemy of Quetzalcoatl, but an ally of Huitzilopochtli. Tezcatlipoca had the power to forgive sins and to relieve disease, or to release a man from the fate assigned to him by his date of birth; however, nothing in Tezcatlipoca's nature compelled him to do so. He was capricious and often brought about reversals of fortune, such as bringing drought and famine. He turned himself into Mixcoatl, the god of the hunt, to make fire. To the Aztecs, he was an all-knowing, all-seeing nearly all-powerful god. One of his names can be translated as "He Whose Slaves We Are".
Some captives were sacrificed to Tezcatlipoca in ritual gladiatorial combat. The victim was tethered in place and given a mock weapon. He died fighting against up to four fully armed jaguar knights and eagle warriors.
During the 20-day month of Toxcatl, a young impersonator of Tezcatlipoca would be sacrificed. Throughout a year, this youth would be dressed as Tezcatlipoca and treated as a living incarnation of the god. The youth would represent Tezcatlipoca on earth; he would get four beautiful women as his companions until he was killed. In the meantime he walked through the streets of Tenochtitlan playing a flute. On the day of the sacrifice, a feast would be held in Tezcatlipoca's honor. The young man would climb the pyramid, break his flute and surrender his body to the priests. Sahagún compared it to the Christian Easter.
To appease Huehueteotl, the fire god and a senior deity, the Aztecs had a ceremony where they prepared a large feast, at the end of which they would burn captives; before they died they would be taken from the fire and their hearts would be cut out. Motolinía and Sahagún reported that the Aztecs believed that if they did not placate Huehueteotl, a plague of fire would strike their city. The sacrifice was considered an offering to the deity.
Tlaloc was the god of rain. The Aztecs believed that if sacrifices were not supplied for Tlaloc, rain would not come and their crops would not flourish. Leprosy and rheumatism, diseases caused by Tlaloc, would infest the village. Tlaloc required the tears of the young as part of the sacrifice. The priests made the children cry during their way to immolation: a good omen that Tlaloc would wet the earth in the raining season. In the Florentine Codex, also known as General History of the Things of New Spain, Sahagún wrote:
They offered them as sacrifices to [Tlaloc and Chalchiuhtlicue] so that they would give them water.
God of the east and water, he wore human skin and was a patron for craftsmen. He was a god of maize and was associated with rain.
The table below shows the festivals of the 18-month year of the Aztec calendar and the deities with which the festivals were associated. In The Florentine Codex children were sacrificed during the first month of the year.
The Flower Wars
It has often been claimed by scholars that the Aztecs resorted to a form of ritual warfare, the Flower War, to obtain living human bodies for the sacrifices in time of peace. This claim however has been severely criticised by scholars such as Ross Hassig and Nigel Davies who claim that the main purpose of the Flower Wars was political and not religious and that the number of sacrificial victims obtained through flower wars was insignificant compared to the number of victims obtained through normal political warfare.
According to Diego Durán's History of the Indies of New Spain, and a few other sources that are also based on the Crónica X, the Flower Wars were originally a treaty between the cities of Aztec Triple Alliance and Tlaxcala and Huexotzingo motivated by a famine in Mesoamerica in 1450. Aztec prisoners were also sacrificed in Tlaxcala and Huexotzingo. The capture of prisoners for sacrifices was called nextlaualli ("debt payment to the gods"). These sources however are contradicted by other sources, such as the Codex Chimalpahin, which mentions "Flower Wars" much earlier than the famine of 1450 and against other opponents than the ones mentioned in the treaty.
Because the objective of Aztec warfare was to capture victims alive for human sacrifice, battle tactics were designed primarily to injure the enemy rather than kill him. After towns were conquered their inhabitants were no longer candidates for human sacrifice, only liable to regular tribute. Slaves also could be used for human sacrifice, but only if the slave was considered lazy and had been resold three times.
The sacrifice ritual
Most of the sacrificial rituals took more than two people to perform. In the usual procedure of the ritual, the sacrifice would be taken to the top of the temple. The sacrifice would then be laid on a stone slab by four priests, and his/her abdomen would be sliced open by a fifth priest with a ceremonial knife made of flint. The cut was made in the abdomen and went through the diaphragm. The priest would grab the heart and tear it out, still beating. It would be placed in a bowl held by a statue of the honored god, and the body thrown down the temple's stairs. The body would land on a terrace at the base of the pyramid called an apetlatl [aˈpet͡ɬat͡ɬ].
Before and during the killing, priests and audience (who gathered in the plaza below) stabbed, pierced and bled themselves as autosacrifice (Sahagun, Bk. 2: 3: 8, 20: 49, 21: 47). Hymns, whistles, spectacular costumed dances and percussive music marked different phases of the rite.
The body parts would then be disposed of: the viscera fed the animals in the zoo; the bleeding head was placed on display in the tzompantli, meaning 'hairy skulls'. Not all the skulls in the tzompantlis were victims of sacrifice. In the Anales de Tlatelolco it is described that during the siege of Tlatelolco by the Spaniards, the Tlatelolcas built three tzompantli: two for their own dead and one for the fallen conquerors, including two severed heads of horses.
Other kinds of human sacrifice, which paid tribute to various deities, approached the victims differently. The victim could be shot with arrows (in which the draining blood represented the cool rains of spring); die in unequal fighting (gladiatorial sacrifice) or be sacrificed as a result of the Mesoamerican ballgame; burned (to honor the fire god); flayed after being sacrificed (to honor Xipe Totec, "Our Lord The Flayed One"), or drowned.
Estimates of the scope of the sacrifices
Some post-conquest sources report that at the re-consecration of Great Pyramid of Tenochtitlan in 1487, the Aztecs sacrificed about 80,400 prisoners over the course of four days. This number is considered by Ross Hassig, author of Aztec Warfare, to be an exaggeration. Hassig states "between 10,000 and 80,400 persons" were sacrificed in the ceremony. The higher estimate would average 14 sacrifices per minute during the four-day consecration. Four tables were arranged at the top so that the victims could be jettisoned down the sides of the temple. Nonetheless, according to Codex Telleriano-Remensis, old Aztecs who talked with the missionaries told about a much lower figure for the reconsecration of the temple, approximately 4,000 victims in total.
Michael Harner, in his 1977 article The Enigma of Aztec Sacrifice, estimates the number of persons sacrificed in central Mexico in the 15th century as high as 250,000 per year. Fernando de Alva Cortés Ixtlilxochitl, a Mexica descendant and the author of Codex Ixtlilxochitl, estimated that one in five children of the Mexica subjects was killed annually. Victor Davis Hanson argues that a claim by Don Carlos Zumárraga of 20,000 per annum is "more plausible." Other scholars believe that, since the Aztecs often tried to intimidate their enemies, it is more likely that they could have inflated the number as a propaganda tool. The same can be said for Bernal Díaz's inflated calculations when, in a state of visual shock, he grossly miscalculated the number of skulls at one of the seven Tenochtitlan tzompantlis. The counter argument is that both the Aztecs and Diaz were very precise in the recording of the many other details of Aztec life, and inflation or propaganda would be unlikely. According to the Florentine Codex, fifty years before the conquest the Aztecs burnt the skulls of the former tzompantli. Mexican archeologist Eduardo Matos Moctezuma has unearthed and studied some tzompantlis.
Sacrifices were made on specific days. Sahagún, Juan Bautista de Pomar and Motolinía report that the Aztecs had eighteen festivities each year, one for each Aztec month. They clearly state that in those festivities sacrifices were made. Each god required a different kind of victim: young women were drowned for Xilonen; children were sacrificed to Tláloc; Nahuatl-speaking prisoners to Huitzilopochtli, and a single nahua would volunteer for Tezcatlipoca. The Ramírez Codex states that for the annual festivity of Huitzilopochtli more than sixty prisoners were sacrificed in the main temple, and prisoners were sacrificed in other large Aztec cities as well.
Not all sacrifices were made at the Tenochtitlan temples; a few were made at "Cerro del Peñón", an islet of the Texcoco lake. According to an Aztec source, in the month of Tlacaxipehualiztli (from February 22 to March 13), thirty-four captives were sacrificed in the gladiatorial sacrifice to Xipe Totec. More victims would be sacrificed to Huitzilopochtli in the month Panquetzaliztli (from 9 November to 28 November) according to the Ramírez Codex. This would mean a figure as low as 300 to 600 victims a year. There is little agreement on the actual figure due to the scarcity of archeological evidence.
Every Aztec warrior would have to provide at least one prisoner for sacrifice. All the male population was trained to be warriors, but only the few who succeeded in providing captives could become full-time members of the warrior elite. Those who could not would become macehualli, workers. Accounts also state that several young warriors could unite to capture a single prisoner, which suggests that capturing prisoners for sacrifice was challenging.
There is still much debate as to what social groups constituted the usual victims of these sacrifices. It is often assumed that all victims were 'disposable' commoners or foreigners. However, slaves - a major source of victims - were not a permanent class but rather persons from any level of Aztec society who had fallen into debt or committed some crime (see Duran, Book of the Gods and Rites, 131, 260). Likewise, most of the earliest accounts talk of prisoners of war of diverse social status, and concur that virtually all child sacrifices were locals of noble lineage, offered by their own parents (compare Cortes, Letters 105 with Motolinia, History of the Indies 118-119 and Duran, Book of the Gods, 223, 242).
Likewise, it is doubtful if many victims came from far afield. In 1454, the Aztec government forbade the slaying of captives from distant lands at the capital's temples (Duran, The Aztecs: History of the Indes, 141). Duran's informants told him that sacrifices were consequently 'nearly always... friends of the [Royal] House' - meaning warriors from allied states (Duran, The Aztecs: History of the Indies, 141, 198). This probably meant that the average Aztec warrior stood as much chance of procuring a victim as he did of himself becoming one - as the Aztec Emperor reportedly told all captives about to be sacrificed: 'today for you, tomorrow for me' (Tezozomoc Vol.2).
Assessment of the practice of human sacrifice
Human sacrifice and other forms of torture—self-inflicted or otherwise—were common to many parts of the New World. Thus the rite was nothing new to the Aztecs when they arrived to the Valley of Mexico, nor was it something unique to pre-Columbian Mexico. Other Mesoamerican cultures, such as the Purépechas and Toltecs, performed human sacrifices as well and from archaeological evidence, it probably existed since the time of the Olmecs (1200–400 BC), and perhaps even throughout the early farming cultures of the region. Although the extent of human sacrifice is unknown among several Mesoamerican civilizations, such as Teotihuacán, what distinguished Maya and Aztec human sacrifice was the importance with which it was embedded in everyday life.
Diego Durán states that Aztecs made "indifferent or sarcastic remarks" when the Spaniards severely criticized the rite. In his Book of the Gods and Rites some of the Nahuas even ridiculed the Christian sensibilities. Instead, they asked the Spaniards to applaud:
The sacrifice of human beings...the honored oblation of great lords and noblemen. They remember these things and tell of them as if they had been great deeds.
Although Aztec accounts mention some victims who wept, “faltered...weakened” or “lost control of their bowels” when going to be sacrificed, this reaction does not seem to have been the norm, as when this occurred, it was viewed as a bad omen—a tetlazolmictiliztli ("insult to the gods") that had to be atoned. Such victims were hurriedly taken aside and slain amidst the congregation's sarcastic jeers of “he (the victim has) quite acquitted himself as a man”. The conquistadors Cortés and Alvarado found that some of the sacrificial victims they freed “indignantly rejected [the] offer of release and demanded to be sacrificed”. Likewise, their slayers, the native priests, were expected to be “kind...never harms anyone” according to Sahagun's informants.
What has been gleaned from all of this is that the sacrificial role entailed a great deal of social expectation and a certain degree of acquiescence. Sahagún's informants told him that key roles were reserved for persons who were considered “charming, quick, dances with feeling…without [moral] defects…of good understanding…good mannered”. For many rites, the victim had such a quantity of prescribed duties that it is difficult to imagine how the accompanying festival would have progressed without some degree of compliance on the part of the victim. For instance, victims were expected to bless children, greet and cheer passers-by, hear people's petitions to the gods, visit people in their homes, give discourses and lead sacred songs, processions and dances. The works of Clendinnen and Brundage imply that only a few select victims had this kind of role, but the Florentine Codex and Duran both make no such distinctions, stating that “those who had to die performed many ceremonies…[and] these [pre-sacrificial] rites were performed in the case of all the prisoners, each in turn”.
Sacrifices were ritualistic and symbolic acts accompanying huge feasts and festivals. Victims usually died in the "center stage" amid the splendor of dancing troupes, percussion orchestras, elaborate costumes and decorations, carpets of flowers, crowds of thousands of commoners, and all the assembled elite. Aztec texts frequently refer to human sacrifice as neteotoquiliztli, “the desire to be regarded as a god”. For each festival, at least one of the victims took on the paraphernalia, habits, and attributes of the god or goddess whom they were dying to honor or appease. Particularly the young man who was indoctrinated for a year to submit himself to Tezcatlipoca's temple was the Aztec equivalent of a celebrity, being greatly revered and adored to the point of people “kissing the ground” when he passed by.
The ecological explanation
In the 1970s, Michael Harner and Marvin Harris argued that the motivation behind human sacrifice among the Aztecs was actually the cannibalization of the sacrificial victims. Harner claimed that very high population pressure and an emphasis on maize agriculture, without domesticated herbivores, led to a deficiency of essential amino acids amongst the Aztecs. While there is universal agreement that the Aztecs practiced sacrifice, there is a lack of scholarly consensus as to whether cannibalism was widespread. Harris, author of Cannibals and Kings, has propagated the claim, originally proposed by Harner, that the flesh of the victims was a part of an aristocratic diet as a reward, since the Aztec diet was lacking in proteins. These claims have been refuted by Bernard Ortíz Montellano who, in his studies of Aztec health, diet, and medicine, demonstrates that while the Aztec diet was low in animal proteins, it was rich in vegetable proteins. Ortiz also points to the preponderance of human sacrifice during periods of food abundance following harvests compared to periods of food scarcity, the insignificant quantity of human protein available from sacrifices and the fact that aristocrats already had easy access to animal protein.
Also in the 1970s, George Murdock and C. Provost (1973) found that of all societies that have practiced human sacrifice all but one had population densities in excess of 26 people per square mile. They found a significant positive correlation of human sacrifice with high populations and inadequate food storage combined with internal warfare for land and resources. However, there was also a lack of correlation between human sacrifice and actual crop failures or famines which points to population dynamics rather than the population density proposed by Murdock and Harner. Ecological factors alone are not sufficient to account for human sacrifice and, more recently, it is posited that religious beliefs have a significant effect on motivation.
The political explanation
The high-profile nature of the sacrificial ceremonies indicates that human sacrifice played an important political function. The Mexica used a sophisticated package of psychological weaponry to maintain their empire, aimed at instilling a sense of fear into their neighbours. The Aztecs controlled a large empire of tribute-paying vassal tribes. The population of native Aztecs was very small compared to the population of the area they controlled. The Aztecs were vulnerable: they would have been outnumbered had their vassal tribes formed alliances and rebelled. To sow dissension among the vassals the Aztecs demanded human victims as part of the annual tribute. The vassals would raid each other to capture prisoners. This encouraged animosity between the vassals and strengthened Aztec political rule. This was a method of political control which was innovative and perhaps unique in human history.
European empires, in contrast, were typically secured through the creation of garrisons and installation of puppet governments in conquered towns or settlements. The Mexica used human sacrifice as a weapon of terror even against the Spanish conquistadors, whose fallen victims were sacrificed and sometimes skinned and their bloody heads placed at the tzompantli. From across the empire even the chiefs of enemy towns were invited, or in the case of tributary towns obliged, to attend sacrificial ceremonies in Tenochtitlan. Their refusal would be considered an act of defiance against the Mexica.
The psychological explanation
For Lloyd deMause it is significant that the victims were invested of a profound cosmological meaning. According to him and a minority of academics who subscribe to an alternative school of thought, "psychohistory", human sacrifices, including sacrifices in Mesoamerica, were an unconscious form of response to the traumatogenic modes of childrearing. DeMause in particular considers the Aztecs' practice of sacrifice as displacement.