Psychological aspects of the boundary: from Ego Skin to relationships with others and spirituality

The theme of boundary, of limit, of separation, runs through, in many ways, the entire history of psychological disciplines. It is therefore a broad, partly nuanced topic, which in this paper we will address from three perspectives: the boundary between the internal world, of the psyche, and the external world, of reality and culture; the boundary between us, the groups to which we belong, and others, that is, the groups with which we are in a relationship; and the boundary between the material world, of the body and objects, and the immaterial world, of ideas and, for many people and cultures, of spirituality.