I would like to end with the proposal that we try to limit the diagnosis borderline state to the kind of case I have described. Freud's statement that the oedipus complex is the kernel of neurosis can also be used in differentiating between neurosis and borderline state. Hysterical acting-out personalities or disabling obsessive character formations, regardless of how severe, should be grouped under hysteria or the obsessional neurosis.

Both psychosis and borderline states can be seen as arrests of development in the symbiotic phase. However, this statement is misleading unless it takes the great complexity of mental development into account and unless the diagnosis is based on an assessment of the total personality development. We should be very careful to avoid oversimplifications, and I would like to stress again that especially the differentiation between borderline states and psychosis may be extremely difficult. I have tried to plead for basing the differential diagnosis on data from all levels of the personality.