We do not think about everything at once all the time. Various mecha nisms allow us to choose from among the themes, issues, topics, feelings, ideas, and memories that might occupy consciousness. One can focus selectively on anything deemed important; yet the methods by which this is accomplished vary greatly. We clinicians assign to these various mech anisms names that fit whatever theoretical system is central to our work-the healthy suppression of "background noise" allows us to pay attention to certain matters; the repression of unconscious conflict may assist our functioning in one...