1266–67 Paris disputations, Franciscan master William of Baglione accused Thomas of encouraging Averroists, most likely counting him as one of the "blind leaders of the blind". Eleonore Stump says, "It has also been persuasively argued that Thomas Aquinas's De aeternitate mundi was directed in particular against his Franciscan colleague in theology, John Pecham." In reality, Thomas was deeply disturbed by the spread of Averroism and was angered when he discovered Siger of Brabant teaching Averroistic interpretations of Aristotle to Parisian students. On 10 December 1270, the Bishop of Paris, Étienne Tempier, issued an edict condemning thirteen Aristotelian and Averroistic propositions as heretical and excommunicating anyone who continued to support them. Many in the ecclesiastical community, the so-called Augustinians, were fearful that this introduction of Aristotelianism and the more extreme Averroism might somehow contaminate the purity of the Christian faith. In what appears to be an attempt to counteract the growing fear of Aristotelian thought, Thomas conducted a series of disputations between 1270 and 1272: De virtutibus in communi (On Virtues in General), De virtutibus cardinalibus (On Cardinal Virtues), and De spe (On Hope). Late career and cessation of writing (1272–1274) In 1272 Thomas took leave from the University of Paris when the Dominicans from his home province called upon him to establish a studium generale wherever he liked and staff it as he pleased. He chose to establish the institution in Naples, and moved there to take his post as regent master. He took his time at Naples to work on the third part of the Summa while giving lectures on various religious topics. He also preached to the people of Naples every day in Lent, 1273. These sermons on the Commandments, the Creed, the Our Father, and Hail Mary were very popular. Thomas has been traditionally ascribed with the ability to levitate. For example, G. K. Chesterton wrote that "His experiences included well-attested cases of levitation in ecstasy; and the Blessed Virgin appeared to him, comforting him with the welcome news that he would never be a Bishop." It is traditionally held that on one occasion, in 1273 at the Dominican convent of Naples in the chapel of Saint Nicholas, after Matins, Thomas lingered and was seen by the sacristan Domenic of Caserta to be levitating in prayer with tears before an icon of the crucified Christ. Christ said to Thomas, "You have written well of me, Thomas. What