The specific psychotherapeutic factors concerning group psychoanalytic psychodrama aim at role-playing and reverse-playing scenes that stage the participants’ emotions. Within a transitional setting in which, therefore, thought is processed, these emotions emerge from group-free associations. While underway, role-playing allows to experience and see interlocutors with whom metaphorically as in Dante’s Divine Comedy a dialogue is sought with characters from the inner theatre belonging to different, achronic situations and historical periods. This is the only way in which a familiar, universal alterity can be found with which to build up a dialogue. Fifth- and sixth-century Greek theatre (Athens, Corinth), whose purpose was catharthic and educational, offers another metaphor, a mental group dialogue oriented towards harmony. The presented clinical material means to clarify this function of group psychodrama. Key words: role-playing, dialogue, body.