Grand Master T’ien-t’ai interprets the two letters of Chih and kuan (concentration and insight) in the Great Concentration and Insight: “I call kuan the wisdom of the Buddha and Chih the insight of the Buddha.” This (interpretation), however, refers to the wisdom and insight of the Buddha in the theoretical section, not the ultimate wisdom and insight of the Buddha at the highest stage of Supreme Enlightenment. For the Great Concentration and Insight is based on the ten realms, the ten aspects, the 3,000 realms of existence, the triple truth and the threefold contemplation, which Grand Master T’ien-t’ai attained, and these thoughts are the real intention of the theoretical section in the first half of the Lotus Sūtra. Therefore, we should remember that the Great Concentration and Insight is the wisdom and insight of the Buddha in the theoretical section.

Risshō Kanjō, A Treatise on Establishing the Right Way of Meditation, Writings of Nichiren Shōnin, Doctrine 2, Page 228