A relational approach to consciousness: categories of level and contents of consciousness

Characterizing consciousness directly is notoriously difficult. This paper proposes an alternative approach: defining consciousness through its relationships to all other consciousness, using category theory. The Yoneda lemma proves that two objects in a category are equivalent if and only if all their relationships to others are identical. The authors introduce key category theory concepts for consciousness researchers and propose several possible definitions of categories of consciousness, in terms of level and contents, using simple examples. They suggest using the categorical structure of consciousness as a gold standard to formalize empirical research, such as color qualia structure at fovea and periphery, and to empirically test theories of consciousness.

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Abstract

Abstract Characterizing consciousness in and of itself is notoriously difficult. Here, we propose an alternative approach to characterize, and eventually define, consciousness through exhaustive descriptions of consciousness’ relationships to all other consciousness. This approach is founded in category theory. Indeed, category theory can prove that two objects A and B in a category can be equivalent if and only if all the relationships that A holds with others in the category are the same as those of B; this proof is called the Yoneda lemma. To introduce the Yoneda lemma, we gradually introduce key concepts of category theory to consciousness researchers. Along the way, we propose several possible definitions of categories of consciousness, both in terms of level and contents, through the usage of simple examples. We propose to use the categorical structure of consciousness as a gold standard to formalize empirical research (e.g. color qualia structure at fovea and periphery) and, especially, the empirical testing of theories of consciousness.