Successful psychotherapy is characterized by a sense of vital intensity and personal intimacy between client and therapist. Current theory and research have left this level of interpersonal contact untouched. The hypothesis is advanced that the intensity and intimacy of interpersonal contact supplies the motivation which allows the patient to make use of the conditions offered by the therapist in the patient's own coming to explore and experience his inner self. The author defines intensity and intimacy of interpersonal contact and presents a tentative scale for its measurement. Finally, the relationship of this concept to other therapeutic conditions offered by the therapist is discussed. (MPJ)