The basis of the capacity to be alone is a paradox; it is the experience of being alone while someone else is present. The capacity to be alone depends on the existence of a good object in the psychic reality of the individual. Maturity and the capacity to be alone imply that the individual has had the chance through good-enough mothering to build up a belief in a benign environment. The capacity to be alone is a highly sophisticated phenomenon and has many contributory factors. The basis of the capacity to be alone is the experience of being alone in the presence of someone. The ego-supportive environment is introjected and built into the individual’s personality, so that there comes about a capacity actually to be alone. The Melanie Klein concept of the depressive position can be described in terms of two-body relationships, and it is perhaps true to say that a two-body relationship is an essential feature of the concept.