This paper defines the essence of "number" which lies at the root of all layers of the universe description, physical laws, and perception as the structuring of ontological difference. Building upon the equivalence of "Existence = Difference = Information" established in the author’s previous work, this study positions number as the resultof information processing that distinguishes distinctness under identity. By doing so, it clarifies that the structures of mathematics, physics, and consciousness are derived from a single logical foundation. This inquiry represents an attempt to liberate the concept of number from abstract symbolic systems and reconstruct it as the fundamental constitutive principle of reality.
Yuya Saito (Sun,) studied this question.