Speculation about this date can be traced to the first edition of The Maya (1966) by Michael D. Coe, in which he suggested the date of December 24, 2011 as one on which the Maya believed "Armageddon would overtake the degenerate peoples of the world and all creation.".[18] This date became the subject of speculation by Frank Waters, who devotes two chapters to its interpretation, including discussion of an astrological chart for this date and its association with Hopi prophecies in Mexico Mystique: The Coming Sixth World of Consciousness (1975).[7] The significance of the year 2012 (but not a specific day) was mentioned briefly by José Argüelles in The Transformative Vision: Reflections on the Nature and History of Human Expression (1975)[19] and (without reference to the ancient Maya) by Terence McKenna and Dennis McKenna in The Invisible Landscape: Mind, Hallucinogens, and the I Ching (1975).[20]