Venerable Śāripūtra tried to teach a smith the practice of meditating on a skeleton to realize the impurity of the body, and a laundryman the practice to obtain a stable mind by counting the number of breaths. His disciples, however, learned little about the Buddha’s teaching in 90 days. Instead, they cultivated wrong views and became icchantika, ones who have no goodness in their nature and, therefore, no possibility of becoming Buddhas. Then the Buddha taught the smith the practice of counting the number of breaths and the laundryman that of meditating on a skeleton, and they understood the teaching immediately. Even Śāriputra, who was reputed as the wisest man, made a mistake in teaching according to a person’s capacity. Needless to say, it is not easy for ignorant, ordinary, and unenlightened masters in the Latter Age of Degeneration to decipher a person’s capacity.

However, such an ordinary master, who cannot discern an individual’s capacity, should solely teach the Lotus Sūtra to his disciples.

Kyō Ki Ji Koku Shō, Treatise on the Teaching, Capacity, Time and Country, Writings of Nichiren Shōnin, Doctrine 3, Page 250