The concept of “brief therapy” contains internal contradictions. The techniques suggested by brief therapists are the same techniques that have been discussed historically in debates on theory of technique, both within and without psychoanalysis (e.g., the experiential factor at the center of the Freud-Ferenczi confrontation is also an important aspect of Gestalt therapy). A time limit is the only operational criterion that allows a rigorous definition of brief therapy; without this criterion it is impossible to discriminate between “brief” and simply “good” therapies (i.e., those in which patients are successfully treated in a short time). An important question is why, with a given patient, a therapist should decide, a priori, to terminate a treatment within a set time. Two clinical examples are presented, illustrating the usefulness of Eissler's concept of parameters as a heuristic framework to identify the potentially defensive nature of both “brief” and “long-term” therapy.