Earnestly intent on acquiring the holiness in quest of which he had entered the cloister, Luther addicted himself to the ascetic life in its fullest rigour, seeking to crucify the flesh by fastings, macerations, and vigils.[157] Shut up in his cell as in a prison, he struggled without intermission against the evil thoughts and evil propensities of his heart. A little bread and a herring were often all his food. Indeed, he was naturally very temperate. Often when he had no thought of purchasing heaven by abstinence, have his friends seen him content himself with the coarsest provisions, and even remain four days in succession without eating or drinking.[158] We have this on the testimony of a very credible witness, Melancthon, and we may judge from it what opinion to form of the fables which ignorance and prejudice have circulated concerning Luther's intemperance. At the period of which we treat there is no sacrifice he would have declined to make, in order to become holy and purchase heaven.[159] When Luther, after he had become Reformer, says that heaven is not purchased, he well knew what he meant. "Truly," wrote he to George, Duke of Saxony, "truly I was a pious monk, and followed the rules of my order more strictly than I can tell. If ever monk had got to heaven by monkery, I had been that monk. In this all the monks of my acquaintance will bear me witness. Had the thing continued much longer I had become a martyr unto death, through vigils, prayer, reading, and other labours."[160] [157] "Summa disciplinæ severitate se ipse regit, et omnibus exercitiis, lectionum, disputationum, jejuniorum, precum, omnes longe superat." (Melancth. Vita Luth.) He observes the utmost rigour of discipline, and in all the exercises of reading, discussion, fastings, and prayers, far surpasses all. [158] "Erat enim natura, valde modici cibi et potus; vidi continuis quatuor diebus, cum quidem recte valeret, prorsus nihil edentem aut bibentem." (Ibid.) For he was naturally moderate in the use of meat and drink; I have seen him, no doubt, when in perfect health, neither eating nor drinking for four successive days. [159] "Strenue in studiis et exercitiis spiritualibus militavit ibi Deo, annis quatuor." (Cochlœus, i.) There, in studies and spiritual exercises, he was a strenuous servant of God for four years. [160] Luth. Op. (W.) xix, 2299. We are touching on the period which made Luther a new man, and which, revealing to him the immensity of the Divine love, fitted him for proclaiming it to the world.