The purpose of this edited volume is to expand on an early classifi cation of paradigms, theories, and models from a variety of contributors dedicated to each paradigm (L'Abate, 2009). Each contributor, in expanding on his/her favorite paradigm, implies or emphasizes her or his theoretical allegiance to the hegemonic importance of that paradigm over others. However, the wide range of paradigm available raises serious questions of whether one single paradigm can achieve such a superior position over others. Consequently, the major issue faced by such an embarrassment of paradigms raises the question on how one can choose one paradigm over others.In a previous publication (L'Abate, 2009) I discussed the role of paradigms, theories, and models trying to make sense of a confusing, uncritical matching of paradigms with theories, paradigms with models, and theories with models. From this publication came forth a classifi cation of paradigms that to my knowledge has not been attempted before, at least in psychology but, as we shall see, attempted frequently in other social science disciplines.Paradigms include theories. Theories include models. Models include dimensions, according to a hierarchical framework. However, what is a paradigm? Many defi nitions equate a paradigm with a model, making it very diffi cult to differentiate among the different components of the proposed classifi cation. Eventually, the best way I could defi ne a paradigm was as "one way to look at reality." Or "a systematic system of values." This way of looking consists of different components chosen to perceive reality according to individual criteria. Different value systems for different individuals. Whether there is a unique, supra-ordinate paradigm, besides evolution, is a question that remains to be answered by most contributors. Is there a supra-ordinate paradigm, and if there is one, how would that supra-ordinate paradigm be chosen?This classifi cation, therefore, begs the question: Which rules, if any, control, govern, or link one paradigm with a theory? Thus far, as far as I know, the only rule relating to the link between a paradigm and a theory, has been by proclamation: a theorist would swear allegiance to a particular paradigm. However, how a particular paradigm was chosen seems by personal preferences of the theorist. Could any other paradigm be chosen instead? Why one particular paradigm instead of another? One