Abstract
“Understanding consciousness through category theory” by N. Tsuchiya and H. Saigo is an ambitious attempt to build up a framework for understanding the level and content of consciousness by category theory with specific examples. I basically agree with all attempts to develop new mathematical tools and apply them to psychological phenomena. However, it seems that there are some mistakes or lack of consideration in the paper, as I point it out as follows. First, I discuss problems that arise when linking the phenomenon of consciousness to the concept of category theory. Second, I argue the significance of using category theory for structural comparison between two systems. Third, I point out a fundamental difficulty in “defining” consciousness by mathematical concepts. Overall, like integrated information theory, the application of category theory does not seem to have solved the conceptual and philosophical problems when dealing with consciousness so far.
