The present study examines Masahiko Aoki’s continual attempts to conceptualize institutions, with main focus on Aoki (Toward a comparative institutional analysis. MIT Press, Cambridge, 2001; J Econ Behav Organ, 79:20–34, 2011). The unique aspect of his approach is identified as his efforts to grasp the dynamic and collective-cognitive nature of institutions. Highly valuing this uniqueness, I identified several difficulties in this approach. In this study, I argue that the profound nature of institutions is beyond the formal description of game theory, which Aoki maintained in his lifetime. I also argue that the Hegelian perspective submitted by Herrmann-Pillath and Boldyrev (Hegel, institutions and economics: performing the social. Routledge, London, 2014) suggests a possible future direction of the research on institutions in economics, albeit not necessarily one amenable to mathematical formulation.