Holmes Welch, Taoism: the parting of the way, Numero 224 dei Beacon paperbacks, Beacon Press, 1966, p. 154, ISBN 0-8070-5973-0. URL consultato il 28 novembre 2011.
«The Sung was succeeded by the dynasty of the Mongol invaders, or the Yuan. The Yuan saw the zenith of Taoist political fortunes. In 1219 Chingiz Khan, who was at that time in the west, summoned the Taoist monk Ch'ang Ch'un to come and preach to him. Ch'ang Ch'un had succeeded Wang Che as head of the Northern School in 1170; he was now seventy-one years old. Four years later, after a tremendous journey across Central Asia, he reached Imperial headquarters in Afghanistan. When he arrived, he lectured Chingiz on the art of nourishing the vital spirit. "To take medicine for a thousand years," he said, "does less good than to be alone for a single night." Such forthright injunctions to subdue the flesh pleased the great conqueror, who wrote Ch'ang Ch'un after his return to China, asking that he "recite scriptures on my behalf and pray for my longevity." In 1227 Chingiz decreed that all priests and persons of religion in his empire were to be under Ch'ang Chun's control and hat his jurisdiction over the Taoist community was to be absolute. On paper, at least, no Taoist before or since has ever had such power. It did not last long, for both Chingiz and Ch'ang died that same year (1227).»
