The system of emotion - cognition - expresion is a base to adapt both to external and our internal world. This is also an actot's way through changing relations in the system.
She/he looks for and offers new forms and new possibilities how the world could look like in a "new" version. A viewer/spectator recunstructs these new forms, versions inside.
Actor and viewer are on a common way of communication. But, this also is a sort of learning how to become a partner of ourselves.
All kinds of arts, and acting too, may be understood as a way of education, a way of forming oneself and of all other people taking part.