(This “Biographical Criticism” was prepared by Prof. Brander Matthews, as an introduction to the Uniform Edition of Mark Twain’s Works, published in 1899). It is a common delusion of those who discuss contemporary literature that there is such an entity as the “reading public,” possessed of a certain uniformity of taste. There is not one public; there are many publics--as many, in fact, as there are different kinds of taste; and the extent of an author’s popularity is in proportion to the number of these separate publics he may chance to please. Scott, for example, appealed not only to those who relished romance and enjoyed excitement, but also to those who appreciated his honest portrayal of sturdy characters. Thackeray is preferred by ambitious youth who are insidiously flattered by his tacit compliments to their knowledge of the world, by the disenchanted who cannot help seeing the petty meannesses of society, and by the less sophisticated in whom sentiment has not gone to seed in sentimentality. Dickens in his own day bid for the approval of those who liked broad caricature (and were therefore pleased with Stiggins and Chadband), of those who fed greedily on plentiful pathos (and were therefore delighted with the deathbeds of Smike and Paul Dombey and Little Nell) and also of those who asked for unexpected adventure (and were therefore glad to disentangle the melodramatic intrigues of Ralph Nickleby). In like manner the American author who has chosen to call himself Mark Twain has attained to an immense popularity because the qualities he possesses in a high degree appeal to so many and so widely varied publics--first of all, no doubt, to the public that revels in hearty and robust fun, but also to the public which is glad to be swept along by the full current of adventure, which is sincerely touched by manly pathos, which is satisfied by vigorous and exact portrayal of character, and which respects shrewdness and wisdom and sanity and a healthy hatred of pretense and affectation and sham. Perhaps no one book of Mark Twain’s--with the possible exception of _Huckleberry Finn_--is equally a favorite with all his readers; and perhaps some of his best characteristics are absent from his earlier books or but doubtfully latent in them. Mark Twain is many sided; and he has ripened in knowledge and in power since he first attracted attention as a wild Western funny man. As he has grown older he has reflected more; he has both broadened and deepened. The writer of “comic copy” for a mining-camp newspaper has developed into a liberal humorist, handling life seriously and making his readers think as he makes them laugh, until to-day Mark Twain has perhaps the largest audience of any author now using the English language. To trace the stages of this evolution and to count the steps whereby the sagebrush reporter has risen to the rank of a writer of world-wide celebrity, is as interesting as it is instructive. I