Fundamentally, Ichinen Sanzen can be explained as follows: every thought (ichinen) encompasses three thousand (san-zen) worlds which make up the entirety of existence and the universe, or more simply, “the three thousand realms are contained in one mind.” The number 3,000 derives from multiplying the conceptual categories of “the mutual possession of the ten realms,” “the ten aspects of existence” and “the three categories of realms.” These basic concepts describe the states of existence. While “3,000” theoretically represents the existing worlds in the universe, the number is meant to describe vastness, universality, or infinity. Ichinen Sanzen of Ri refers to the theoretical principles found in the theoretical or “shakumon” section of the Lotus Sutra.