Though they excoriated such practices with righteous fervor and sought to stamp them out wherever possible, to the sixteenth century missionary friars. the widespread and continuing use of hallucinogenic plants in Indian America seems to have been at least as much a cause of wonderment and fascination as it was of religious indignation. One man's devil being another man's god, the Spaniards were perhaps not wholly off the mark. They perceived quite correctly that the sacred hallucinogens had played an important role in Indian life (in religious ceremonial, individual vision quests, curing, and divination) for many centuries before Columbus. These practices had all survived the Conquest. Hence they had to be eradicated at 'all costs if Christian instruction was to be complete. For the Indians, these costs were great indeed: detention, questioning under mental pressure or physical torture. flogging, enslavement. even death . Chrislianization proceeded apace through the first century after the Conquest, without necessarily displacing the older beliefs and practices, including those involving the magical hallucinogenic plants. The Prehispanic native supernatural gradually became populaIed with new denizens-saints, angels, devils, the Virgin, Christ, God the Father- who merged with the old gods more often than they replaced them altogether. In curing or divination with the aid of hallucinogens. saints and Virgin became the patrons; whose aid was Invoked by the native practitioners in rituals, the folk Catholic trappings of which barely concealed their pagan ancestry.