Jack Black was an experimental psychologist: he discovered slowly and painfully, as most do, the psychological character of himself and of the world in which he was placed. Thus he explored the law of habit and the purely mental quality of self-control long before he attempted to apply his knowledge to his own case. Any habit, he maintains, apropos of the opium habit, can be broken provided the victim *wants* sufficiently to change, and he notes the power of substitution, welcoming even his worries as distractions, mentally, from the obsession of opium. His emphasis on the necessity of a subjective desire for change is an unerring diagnosis of self. He wanted another kind of life enough to make it come true. That is the great distinction of Jack Black as professional lawbreaker and person. His case is so common in our restless, mobile civilization that it may be called typical or standard. An active, intelligent, likable boy with no stable ties, he adventured on the open road, almost by accident, the wide world tempting him on, took what he wanted, learned the habits and the resources of vagrancy, of criminality, of vice. But he did not sink to the dregs per formula. He went to the top of his society. Stirred by emulation with the only companions he had—hoboes, thieves, gamblers, yeggs—he distinguished himself not only by success in individual exploits but by a superiority of character that would not break, “snitch,” or play the other fellow’s game—and by loyalty to his mates. Then came as he was emerging from youth the chance that landed him in a well-run Canadian prison and fertilized the seed of intellectual interest by giving him access to a good library. For the first time he discovered consciously his own mind—the interest of it—and from this period it is evident that the habit of reading, of thinking, gained on him until with relentless logic his mind, thus freed and fed, convinced him that his boy’s life of defiance and lawlessness was wrong. After he was convinced, it took years to free himself from all the implications of twenty years of crime. But once convinced, with a mind of that quality, the result was inevitable. Strange irony that the mental life so essential to Black’s salvation should have been further fostered by the gift of a library which Abe Ruef gave to the prison where he and Black happened to be fellow prisoners. Ruef had taken the money which he bestowed in this form on his fellow criminals from the public of San Francisco. Mr. Fremont Older, as a powerful newspaper editor, was largely responsible for putting Ruef into the prison (and later in freeing him!) where Ruef was indirectly an instrument in freeing Jack Black from his bonds.