I think that symbolism originates in projective identification, first of all in the relationship to the breast then to mother's whole body. When this projection results in mutual damage or an excessively omnipotent identification of a 'sticky' kind, symbols formed are excessively concrete, empty of meaning or bizarre. If the projection is not excessively envious or narcissistic and if the mother's response is not mutilating, the infant introjects a breast and mother capable of the symbolic function, in Bions' terms, capable of converting a into b elements. When this happens symbol formation on the depressive level can proceed in the way I described in 1957.