Therapists have a mandate to bring about change, and family therapists appear to have unusual leverage to fullfill such a mandate, that is, to facilitate changes rapidly and effectively. Because and in spite of this mandate, the very notion of change deserves critical reflection. The history of ideas and our clinical experience teach us that changes may be problematic. They may come too fast or too slowly, may endure or fade away, may turn out to be desirable or undesirable, equitable or inequitable, and may, when further consequences and larger systems levels are taken into account, be beneficial or disastrous. This essay examines some of the problematical and contradictory aspects of change and delineates two perspectives on change--systemic optimism and systemic pessimism.