There are two ways of meditating on the doctrine of “3,000 existences contained in one thought.” One is the “theoretical” way, and the other is the “actual” way. Grand Masters T’ien-t’ai and Dengyō practiced the former. I, Nichiren, now practice the latter. As my method of practicing meditation is superior, difficulties befalling me are harder to bear. What T’ien-t’ai and Dengyō propagated was based on the doctrine of “3,000 existences contained in one thought” expounded in the theoretical section [of the Lotus Sūtra], while what I, Nichiren, propagate is based on the doctrine of “3,000 existences contained in one thought” in the essential section. The difference between the two is as great as the difference between heaven and earth. Remember this especially at the time of the last moment of life. Have an unwavering faith in the Lotus Sūtra and continue chanting the daimoku, which is the right way of meditation based on the “actual” doctrine of “3,000 existences contained in one thought. “

Toki Nyūdō Go-henji: Chibyō-shō, A Response to Lay Priest Lord Toki: Treatise on Healing Sickness, Writings of Nichiren Shōnin, Doctrine 2, Page 257.

The importance of this letter is underscored in the Introduction:

According to Nichiren, the greater difficulties he and his followers encounter show the appearance of the “actual” doctrine of “3,000 existences contained in one thought” in contrast to the “theoretical” doctrine advocated by T’ien-t’ai and Dengyō, and it represents the true doctrine of the essential section.

Here lies the uniqueness of Nichiren Buddhism. Nichiren Shōnin termed his own interpretation of the doctrine of “3,000 existences contained in one thought actual” and called that of T’ien-t’ai and Dengyō “theoretical.” On the basis of this “actual” interpretation of the doctrine of “3,000 existences contained in one thought,” Nichiren Shōnin found the way of saving the populace by having them put their faith in and chant the daimoku.

This marks the completion of the second week of my 100-day goal. I’ve finished Doctrine 2 (the second volume), which puts me on a pace to cover all seven volumes in the 14.3 weeks that comprise 100 days.