The author provides a survey of the most significant approaches to a theory of group therapy. Following Hofstätter, he distinguishes 'group dynamics' from group therapy. Further, he sketches Bion's concept of the working group and the regressed group. The following perspectives are offered as an interpretative framework for therapeutic work with groups: the group (a) as a model of the family, (b) as a metapsychological model ('group analysis'), (c) as a social field for growth and crises of the personality (according to Erikson), and (d) as a medium for the enhancement of communication with the specific task of strengthening the ego integrity of the group.