Didier Anzieu, The Skin Ego: A Psychoanalytic Approach to the Self

"The primary function of the skin is as the sac which contains and retains inside it the goodness and fullness accumulating there through feeding, care, the bathing in words. Its second function is as the interface which marks the boundary with the outside and keeps that outside out; it is the barrier which protects against penetration by the aggression and greed emanating from others….Finally, the third function – which the skin shares with the mouth and which it performs at least as often – is as a site and a primary means of communicating with others, of establishing signifying relations…"