Criticism directed at neoclassical economics has failed to replace it with a similar grand theory. The author argues that one possible explanation may lie in the failure of economists to formulate an opinion as to the philosophical foundations of the author’s object of study. The paper aims to discuss this issue. The argument proceeds in two steps. First, the authors review the prevailing philosophical view of “the self-interest theory (S)”, which is one of the most powerful constituents of today’s economics, and social theorizing in general. Second, the authors present a reasoning framework in
which rationality becomes intelligible within a schema of integrating the self’s external and internal conditionalities into a unified view of human reasoning.