which had occurred immediately before them or to those which followed straight afterwards. Of paramount importance were the positions which they happened to occupy in the 260-day and 360+5-day calendar counts. Also significant were the 584-day Venusian cycle, and indeed the "age-growth cycles" of the people involved (which extended from birth through to old age). Texts There is a dearth of material from which Aztec philosophy can be studied with a majority of extant texts written after conquest by either Spanish colonists and missionaries, or Christianised Spanish educated natives. The conquistadors burned most Aztec (and Mayan) texts. Pre-conquest sources include the Codex Borgia and the Codex Borbonicus (written about the time of conquest). Post-conquest texts include the Florentine Codex, Codex Mendoza and the Codex Magliabechiano, including others. See also Tlacaelel Government of the Aztec Empire Indigenous American philosophy Mesoamerican literature References Sources Maffie, James; Aztec Philosophy: Understanding a World in Motion; 2014: Notre Dame Philosophical Reviews. Leon-Portilla, Miguel; Native Mesoamerican Spirituality; Jun 27 2002. Leon-Portilla, Miguel; Aztec Thought and Culture: A Study of the Ancient Nahuatl Mind; 1990. Leon-Portilla, Miguel; Fifteen Poets of the Aztec World; October 15, 2000. External Links The Mesoamerican Philosophy Renaissance Philosophy Philosophy Latin American culture Medieval philosophy Indigenous American philosophy History of indigenous peoples of North America