Analysis of patients with narcissistic pathology offers an opportunity to study the development of specific distortions of self and object representations. Two cases are presented illustrating the development of idealizations and grandiosity. For one patient these were manifestations of a developmental arrest; for the other, defenses against object-instinctual conflict. Differences in the function of idealizations and grandiosity in the two patients are attributed to the role of aggression and to the degree of separation-individuation attained. Treatment implications with references to the works of Kohut and Kernberg are considered.