 One unifying theme, on the striking formal similarities of analysis in seemingly diverse fields, occurred only in the course of writing on them—from consumer's behavior and production economics of the firm to international trade, business cycles, and income analysis.It dawned on the author that he was prodigal "in proving essentially the same theorems" over and over.His failure of initial intuition, so he suggests, might be less surprising in light of the few economic writings then extant concerned with formulating "meaningful theorems" – hypotheses "about" empirical data—that could conceivably be refuted "by" empirical data (pp.