(1) Early object relationships, separation anxiety and symbiosis can only be accurately described by distinguishing between the role of the internal and external objects. (2) Symbiosis and separation anxiety are intrapsychic concepts and do not describe 'who leaves whom' or 'who does what to whom'. (3) The role of aggression in separation anxiety is stressed. (4) A hypothesis is presented of the prototype of separation anxiety, analogous to Freud's formulation of the birth trauma. (5) The relationship between separation anxiety and object constancy is discussed. (6) Two meanings of object constancy are defined: early object constancy and late or mature object constancy. (7) It is incorrect that need-fulfilment ceases in early childhood in favour of object constancy. Need-fulfilment lessens, but continues until relatively late in life. (8) Spitz's formulations regarding separation anxiety and stranger anxiety are critically re-evaluated and put into a different theoretical framework.