Expounding the Mind & Expounding the Nature
Setsu means “teach,” “explain,” or “expound.” Shin means “mind,” and sho means “the essence,” or “the nature.” So sesshin means “expounding the mind” and sessho means “expounding the nature.” Some Chinese Buddhist monks asserted that expounding the mind and expounding the nature belong within the sphere of intellectual effort, and so to make such effort to explain the mind and essence is not only unnecessary but also detrimental to attainment of the Buddhist truth. They believed that the Buddhist truth could never embrace intellectual understanding. Master Dogen had a different opinion. He thought that the concepts sesshin and sessho in Buddhist thought refer to something much more real. He understood sesshin-sessho as the manifestation of the mind and the manifestation of the nature in the real world. Master Dogen saw no reason to deny the concepts sesshin and sessho; instead he used them to explain the fundamental theory of Buddhism.