"Augustinian ideas were decidedly anti-experimental, yet when Aristotelian experimental techniques were made available to the West they were not shunned. Still, Augustinian thought was well ingrained in medieval society[?] and was used to show alchemy as being un-Godly. Ultimately, by the high middle ages, this line of thought created a permanent rift separating alchemy from the very religion that had fostered its birth."

"In the fourteenth century, these views underwent a major change. William of Ockham, an Oxford Franciscan who died in 1349, attacked the Thomist view of compatibility between faith and reason. His view, widely accepted today, was that God must be accepted on faith alone; He could not be limited by human reason. Of course this view was not incorrect if one accepted the postulate of a limitless God versus limited human reasoning capability, but it virtually erased alchemy from practice in the fourteenth and fifteenth centuries. (Hollister p. 335) Pope John XXII in the early 1300s issued an edict against alchemy, which effectively removed all church personnel from the practice of the Art. (Edwards, p.49) The climate changes, Black plague, and increase in warfare and famine that characterized this century no doubt also served to hamper philosophical pursuits in general."