In this chapter we will explore how developments in system theory has led to a new paradigm called personality systematics and suggest that a new trend toward unified clinical science is now within reach (Magnavita, 2006). It is suggested that knowledge of personality systematics has importance in understanding how human beings function and are led to states of dysfunction, as well as offering guidelines for clinical treatment or psychotherapeutics (Magnavita, 2005b). System theory (von Bertalanffy, 1968) is considered by many one of the most important paradigmatic shifts that occurred in science during the twentieth century. Prior to the development of system theory, scientists were mostly interested in understanding linear causation, which fails to account for the complexity in many open systems, which are being mutually shaped by both internal and internal elements and processes.