In social science, the wider epistemological debates regarding polarizing perspectives of rationality (explanation through deterministic approach) and interpretive understanding (understanding through non-physical human mind) in explaining or making sense of lifeworld or social system have been critically examined in this paper. In doing so, this article explores Habermas’s Theory of Communicative Action (rationality in socially depended situation) and psychological (strategic action) Game Theory (a deterministic model for rational choice) and, hence, identifies an intriguing link between instrumental/mechanistic and non-instrumental issues regarding rationality concept