It is argued that one type of activity that can help move psychology along the path toward unification is a comparative analysis of grand theories that have unification as a goal, an analysis focused on the theories' relative ability to provide unity within the science. This chapter is intended to serve as a model for such an analysis, comparing the two general behavioral theories of radical behaviorism and paradigmatic behaviorism on the substantive dimensions of fact, theory, and methodology. Several benefits of such a comparative analysis are noted, including, in the present case, further specification of how a science can progress toward unification through generational growth.