Kubie discusses the problems of hypnotism, and emphasizes the need for research to explain what hypnotism is and how it works. He highlights the danger of begging the question inherent in a system in which hypnotism is used at the same time as the instrument and object of the investigation. For future studies he suggests that recent material on so-called sensory deprivation points the way toward the investigation of the relative roles played in the induction of hypnosis by exteroceptive, proprioceptive, and enteroceptive afferents on preconscious as well as conscious levels. The problems arising out of the uncertainty as to which psychological concepts are descriptive and which are explanatory are examined. Kubie stresses the difference between the process of induction and the fully achieved hypnotic state, as yet unexplained.