Psychotherapists should be scientists first and technicians second. The principles of scientific thought usually require rejection of foreign-theory technique when that technique cannot be appropriately justified by the currently held theory. Empiricism is not absolutely precluded. However, it is to be reluctantly and infrequently used; its hazards are always to be fully recognized; the search for scientific facts to replace the empirical ones should be fervent and incessant. Technical eclecticism may enrich the psychotherapist's technical repertoire. But, there is no significant scientific proof that it enhances the therapist's effectiveness. In either case, there is virtually never sufficient justification “for the practicing psychotherapist to be content in the role of a technician rather than that of a scientist …” (Lazarus, 1967). I submit that therapeutic competence is probably more directly related to technique-use based on well understood, scientifically valid theory than to any other single determinant.