"Frankness is a jewel," said Mark Twain; "only the young can afford it." Precisely at the moment when he was writing to Robert Ingersoll that remarkable letter which displayed a thirst for crude atheism comparable only to the thirst for crude alcohol of a man who has been too long deprived of his normal ration of simple beer, he was at work on "Tom Sawyer." "It is not a boys' book, at all," he says. "It will only be read by adults. It is only written for adults." Six months later we find him adding: "I finally concluded to cut the Sunday School speech down to the first two sentences, leaving no suggestion of satire, since the book is to be for boys and girls." Tell the truth or trump--but get the trick! Almost incredible, in fact, to any one who is familiar with the normal processes of the literary mind, was Mark Twain's fear of public opinion, that fear which was the complement of his prevailing desire for success and prestige. In later life it was his regular habit to write two letters, one of which he suppressed, when he was addressing any one who was not an intimate friend upon any subject about which his instinctive feelings clashed with the popular view. These unmailed letters in which, as Mr. Paine says, "he had let himself go merely to relieve his feelings and to restore his spiritual balance," accumulated in such a remarkable way that finally, as if he were about to publish them, Mark Twain for his own amusement wrote an introduction to the collection. "Will anybody contend," he says, "that a man can say to such masterful anger as that, Go, and be obeyed?... He is not to _mail_ this letter; he understands that, and so he can turn on the whole volume of his wrath; there is no harm. He is only writing it to get the bile out. So to speak, he is a volcano; imagining himself erupting does no good; he must open up his crater and pour out in reality his intolerable charge of lava if he would get relief.... Sometimes the load is so hot and so great that one writes as many as three letters before he gets down to a mailable one; a very angry one, a less angry one, and an argumentative one with hot embers in it here and there." Tragic Mark Twain! Irresponsible child that he is, he does not even ask himself whether he is doing right or wrong, so unquestioningly has he accepted the code of his wife and his friends. That superb passion, the priceless passion of the satirist, is simply being wasted, like the accumulated steam from an engine whose machinery has broken down and cannot employ it.