psychotic (paranoid and depressive) anxieties underlie infantile neurosis… anxieties of a psychotic nature are in some measure part of normal infantile development and are expressed and worked through in the course of the infantile neurosis.
Klein advances her central thesis that psychotic anxiety is not merely pathological but constitutes a universal developmental foundation, present in all infantile experience and reworked in normal neurotic development.
, Envy and Gratitude and Other Works 1946-1963, 1957thesis