Psychology has been remarkably successful as both a basic and applied science despite serious and persistent conflict between its many theoretical camps and schools of thought. By far the most influential approaches to conceptualizing clinical practice in psychology have been the traditional theoretical orientations, even though they are widely viewed as inadequate and incomplete. This article reviews the underlying reasons for these conflicts and then discusses the emergence of a unified scientific framework that moves the profession beyond these problems. Outmoded conceptual frameworks are not appropriate for a science-based profession, and professional psychology needs to consider making a systematic transition to a comprehensive scientific approach to understanding human development, functioning, and behavior change.