The purpose of this chapter is to review critically the usefulness of differentiations made in an earlier publication (L'Abate, 2009) that was basic to the Table of Contents for this volume. How does that classification hold up in front of the many paradigms introduced then and now in this volume? To select a particular paradigm over others and make sense of such a bewildering array of paradigms, each claiming an important position in theory-construction, four different criteria will be necessary. Two criteria of abstraction and generality are descriptive. Two processes of equipotentiality and equifinality are explanatory because they integrate various levels of observation and interpretation.