This paper proffers a dialogical theory of decision-making: decision-makers are engaged in two modes of rational decisions, instrumental and existential. Instrumental rational decisions take place when the DM views the self externally to the objects, whether goods or animate beings. Existential rational decisions take place when the DM views the self in union with such objects. While the dialogical theory differs from Max Weber’s distinction between two kinds of rationality, it follows Martin Buber’s philosophical anthropology. The paper expounds the ramifications of the dialogical theory in understanding structures of exchange considering assessments of diverse thinkers.