What heals in groups? This question seems even more difficult than the question about the effect of individual therapies, not only at first glance. After all, groups represent a far more complex situation of human contact. They lack many characteristics of the rather distant, artificial situation of the individual setting. We want to investigate what causes change. On which levels does change occur at all? What can one understand by this? Is psychological change possible through a “healing through love”, as Freud already noted, or does the integration of shadow aspects and negativity work, which is more reminiscent of Jung? Is it the sharing of common foundations of experience that can promote the desired de-idealization of one’s own ideas? And how do intervention paths such as interpretation and amplification stand in this context? Are there other forces that can be effective in groups beyond this?