theoretical teaching ［迹門］ ( shakumon): Also, trace teaching. The first half of the twenty-eight-chapter Lotus Sutra, from the “Introduction” (first) chapter through the “Peaceful Practices” (fourteenth) chapter. In The Words and Phrases of the Lotus Sutra, T’ien-t’ai (538–597) classifies the Lotus Sutra into two parts: the first fourteen chapters, or the theoretical teaching, and the latter fourteen chapters, or the essential teaching. The theoretical teaching takes the form of preaching by a “provisional Buddha,” the historical Shakyamuni Buddha depicted as having first attained enlightenment during his lifetime in India. The essential teaching takes the form of preaching by the Buddha who has discarded this provisional status and revealed his true identity as the Buddha who attained enlightenment in the unimaginably remote past. T’ien-t’ai compared the relationship between the Buddha in his true identity and his provisional manifestation, or between their respective teachings, to that of the moon in the sky and its reflection on the surface of a pond.
The core of the theoretical teaching is the “Expedient Means” (second) chapter, which reveals the true aspect of all phenomena and that the ten factors endow all life. The “Expedient Means” chapter also states that the Buddha’s sole purpose is to lead all people to Buddhahood, and that the three vehicles of voice-hearers, cause-awakened ones, and bodhisattvas are no more than expedient means to lead people to the one Buddha vehicle. Though the attainment of Buddhahood by voice-hearers and cause-awakened ones was deemed impossible in the earlier teachings, the theoretical teaching of the Lotus Sutra states that they will attain Buddhahood in the future. Also in this part of the sutra, at the urging of the Buddha, countless bodhisattvas vow to propagate the Lotus Sutra after Shakyamuni Buddha’s death. They make this vow in the presence of Many Treasures Buddha and all the other Buddhas assembled from throughout the universe. See also essential teaching.