Various psychoanalytic concepts of trauma are evaluated. The suggestion is made that some modification of Freud's original stimulus barrier concept would make it compatible with the clinical observation of isolated dysfunctions of specific ego operations. It is proposed that Freud's barrier should also be thought of as protecting specific ego functions or their nuclear forerunners. Penetration of this barrier creates a traumatic event rendering such an ego function ineffective and possibly interfering with its subsequent development. Clinical examples are presented.