Therefore, although what was realized in the minds of such great masters might be the same, Aśvaghoṣa and Nāgārjuna were superior to Kāśyapa and Ānanda with the dharma they spread; T’ien-t’ai was superior to Aśvaghoṣa and Nāgārjuna, and Dengyō was superior to T’ien-t’ai. As the world declines into the Latter Age, and the wisdom of the people becomes shallower, the teaching of the Buddha grows more profound. Ordinary sickness can be cured by ordinary medicine, but grave sickness requires special medicine. The weak need the strong for assistance.

Hōon-jō, Essay on Gratitude, Writings of Nichiren Shōnin, Doctrine 3, Pages 57.