A complete theory of hypnosis cannot be stated in terms of the libidinal relation between hypnotist and subject. One must also take ego functioning into account: fluctuations in depth of hypnosis represent ego-defensive maneuvers. Hypnosis is a special case of the self-excluding function of the ego, similar to the regression when one performs routine tasks requiring little cognitive function or conscious participation. When the subject dares not relinquish ego control, as in severe anxiety, or when selective ego regression is not possible because, for example, of poor ego integration in a psychotic, he cannot be hypnotized.