Why Does One Consciousness Exist?

This paper examines the fundamental question, “Why does One Consciousness exist?”, from the perspectives of ontology, epistemology, and cosmology. Since all particular entities that appear in the universe can be understood as outcomes or manifestations, their existence presupposes an underlying foundation that makes such emergence possible. In this study, that foundation is identified as the One Consciousness. Based on the principle that cognition arises through difference, this paper proposes the hypothesis that the One Consciousness undergoes self-differentiation in order to enable self-recognition, thereby unfolding a diverse universe. The evolution of the universe can thus be interpreted as a process of self-recognition progressing from differentiation toward reintegration. Within this framework, human consciousness functions as a focal point through which the One Consciousness recognizes itself. The aim of this paper is not to treat the One Consciousness as a religious presupposition, but rather to demonstrate that it can be understood as the ontological ground that most coherently explains existence, manifestation, and the possibility of experience.