Before he left his prison he had begun the book which has made his name immortal. The history of that book is remarkable. The author was, as he tells us, writing a treatise, in which he had occasion to speak of the stages of the Christian progress. He compared that progress, as many others had compared it, to a pilgrimage. Soon his quick wit discovered innumerable points of similarity which had escaped his predecessors. Images came crowding on his mind faster than he could put them into words: quagmires and pits, steep hills, dark and horrible glens, soft vales, sunny pastures; a gloomy castle, of which the courtyard was strewn with the skulls and bones of murdered prisoners; a town all bustle and splendor, like London on the Lord Mayor's Day; and the narrow path, straight as a rule could make it, running on uphill and down hill, through city and through wilderness, to the Black River and the Shining Gate. He had found out--as most people would have said, by accident; as he would doubtless have said, by the guidance of Providence--where his powers lay. He had no suspicion, indeed, that he was producing a masterpiece. He could not guess what place his allegory would occupy in English literature, for of English literature he knew nothing. Those who suppose him to have studied the "Fairy Queen," might easily be confuted, if this were the proper place for a detailed examination of the passages in which the two allegories have been thought to resemble each other. The only work of fiction, in all probability, with which he could compare his pilgrim, was his old favorite, the legend of Sir Bevis of Southampton. He would have thought it a sin to borrow any time from the serious business of his life, from his expositions, his controversies, and his lace tags, for the purpose of amusing himself with what he considered merely as a trifle. It was only, he assures us, at spare moments that he returned to the House Beautiful, the Delectable Mountains, and the Enchanted Ground. He had no assistance. Nobody but himself saw a line till the whole was complete. He then consulted his pious friends. Some were pleased. Others were much scandalized. It was a vain story, a mere romance about giants, and lions, and goblins, and warriors, sometimes fighting with monsters, and sometimes regaled by fair ladies in stately palaces. The loose, atheistical wits at Will's might write such stuff to divert the painted Jezebels of the court; but did it become a minister of the Gospel to copy the evil fashions of the world? There had been a time when the cant of such fools would have made Bunyan miserable. But that time was passed, and his mind was now in a firm and healthy state. He saw that in employing fiction to make truth clear and goodness attractive, he was only following the example which every Christian ought to propose to himself; and he determined to print.