Blood Given Freely, Set Against Blood Taken

Scholars of Aztec religion read autosacrifice and human sacrifice as related but conceptually distinct within the same debt theology. Autosacrifice was blood a person gave from their own body, voluntarily and repeatedly, matching in kind, if not in scale, the self inflicted wounds the gods gave themselves at Teotihuacan to start the sun moving. Human sacrifice, most often of war captives, was blood taken rather than given, and Mexica sources frame the captured warrior's death differently again, sometimes as an honored continuation of his own martial identity rather than a simple extraction, a distinction anthropologists and historians such as David Carrasco have worked to keep visible against flatter popular readings that treat all Aztec bloodletting as a single undifferentiated practice of violence.

Blood offered from one's own body carried an immediacy human sacrifice could not, since it needed no captive, no war and no priestly apparatus beyond a spine and a strip of paper, and its sheer frequency in the archaeological and textual record, evidenced by bloodstained paper offerings recovered from Aztec sites and by the codices' repeated depiction of the act, argues that autosacrifice, not the more famous mass sacrifice, was the daily texture of Aztec religious devotion for most people who practiced it.