The capacity to be alone in contrast to the wish or fear to be alone is an important sign of maturity. In some patients, toward the end of analysis, silence on the patient's part may be an achievement rather than a resistance. The prototype of the capacity to be alone is the infant's experience of being alone while the mother is present. In the adult, the wish to be alone with another is particularly shown in the shared solitude of two partners after intercourse. The necessary conditions for the capacity to deal with feelings originally aroused by the primal scene are a good 'internal object', a requisite degree of ego development and maturation, and establishment of the concept of 'I', as well as repeated experiences in childhood of drive derivatives tolerated by an adult. These derivatives would not be tolerated by the child itself when alone.