Raymond Lulli's turning point

Faithless to his wife, he was always in the pursuit of some new beauty, till his heart was fixed at last by the lovely but unkind Ambrosia de Castello. This lady, like her admirer, was married; but, unlike him, was faithful to her vows, and treated all his solicitations with disdain. Raymond was so enamoured, that repulse only increased his flame; he lingered all night under her windows, wrote passionate verses in her praise, neglected his affairs, and made himself the butt of all the courtiers. One day, while watching under her lattice, he by chance caught sight of her bosom, as her neckerchief was blown aside by the wind. The fit of inspiration came over him, and he sat down and composed some tender stanzas upon the subject, and sent them to the lady. The fair Ambrosia had never before condescended to answer his letters; but she replied to this. She told him that she could never listen to his suit; that it was unbecoming in a wise man to fix his thoughts, as he had done, on any other than his God; and entreated him to devote himself to a religious life, and conquer the unworthy passion which he had suffered to consume him. She, however, offered, if he wished it, to show him the fair bosom which had so captivated him. Raymond was delighted. He thought the latter part of this epistle but ill corresponded with the former, and that Ambrosia, in spite of the good advice she gave him, had at last relented, and would make him as happy as he desired. He followed her about from place to place, entreating her to fulfil her promise: but still Ambrosia was cold, and implored him with tears to importune her no longer; for that she never could be his, and never would, if she were free tomorrow. "What means your letter, then?" said the despairing lover. "I will shew you!" replied Ambrosia, who immediately uncovered her bosom, and exposed to the eyes of her horrorstricken admirer a large cancer which had extended to both breasts. She saw that he was shocked; and extending her hand to him, she prayed him once more to lead a religious life, and set his heart upon the Creator, and not upon the creature. He went home an altered man. He threw up, on the morrow, his valuable appointment at the court, separated from his wife, and took a farewell of his children, after dividing one-half of his ample fortune among them. The other half he shared among the poor. He then threw himself at the foot of a crucifix, and devoted himself to the service of God, vowing, as the most acceptable atonement for his errors, that he would employ the remainder of his days in the task of converting the Mussulmans to the Christian religion. In his dreams he saw Jesus Christ, who said to him, "Raymond! Raymond! follow me!" The vision was three times repeated, and Raymond was convinced that it was an intimation direct from heaven. Having put his affairs in order, he set out on a pilgrimage to the shrine of St. James of Compos tello, and afterwards lived for ten years in solitude amid the mountains of Aranda. Here he learned the Arabic, to qualify himself for his mission of converting the Mahometans. He also studied various sciences, as taught in the works of the learned men of the East, and first made acquaintance with the writings of Geber, which were destined to exercise so much influence over his future life.

--from "The Alchymists"
Extraordinary Popular Delusions and the Madness of Crowds
by Charles Mackay