It was one of Mark Twain's favorite fancies, Mr. Paine says, that life should begin with old age and progress backwards. We can understand it now; we can understand why his mind was essentially retrospective and why so much of his writing deals with his childhood. The autobiographical impulse is normal in old age: when men cannot build on hope they build on memory, their minds regress into the past because they no longer have a future. It is generally understood, therefore, that when people in middle age occupy themselves with their childhood it is because some central instinct in them has been blocked by either internal or external obstacles: their consciousness flows backward until it reaches a period in their memory when life still seemed to them open and fluid with possibilities. Who does not see in the extraordinary number of books about boys and boyhood written by American authors the surest sign of the prevalence of that arrested moral development which is the result of the business life, the universal repression in the American population of all those impulses that conflict with commercial success? So it was with Mark Twain. In him the autobiographical impulse, characteristic of old age, awoke very early: as far back as 1880 we find him "attempting, from time to time," according to Mr. Paine, "an absolutely faithful autobiography"; and he resumed the attempt in 1885, at the time when he was assisting Grant with his Memoirs. It remained his dominant literary impulse. "Earn a character if you can, and if you can't," says Pudd'nhead Wilson, "then assume one." Mark Twain had "assumed" the character of his middle years; he had only truly lived, he had only been himself, as a child, and the experience of childhood was the only experience he had assimilated. That is why he was perpetually recurring to his early life in Hannibal, why the books he wrote _con amore_ were books about childhood, and why he instinctively wrote not only about, but also for, children. By doing so he knew, or something in him knew, what many another American author has known since, that he was capturing the whole public. Ten million business men--that was the public, the masculine public, of Mark Twain's time. And are not business men in general, in a sense not quite intended by the coiner of the phrase, "children of a larger growth"?