摘要:Tsuchiya & Saigo (2019) proposed the idea that the category theory is the powerful tool for scientific approach towards the mystery of consciousness. Perception, illusion,and consciousness are closely related, and so they also analyzed how to understand the phenomena in some types of visual illusion in terms of the category theory. In this commentary, I discuss about some perceptual phenomena and their theories, such as visual illusion, perceptual constancy, bistable figures, and ill-posed problem of perception, and the limitation of the current theory. Although the power of category theory in the cognitive science is still unclear, I also discuss the potential of category theory to understand illusion and perception from different viewpoint than the existing theories..