Nichiren accepted the received Mahāyāna view that “all sentient beings have the Buddha nature,” as well as Tendai ideas about the Buddhahood of insentient beings, but did not himself develop a particular theory of Buddha nature. Rather, as a number of postwar Nichirenshū scholars have pointed out, he emphasized the daimoku as the “seed” of Buddhahood. While ideas about the “Buddha-seed” (busshu) have a long and varied history, Nichiren’s concept draws explicitly on Chih-i’s Fa-hua hsüan-i, which describes the Buddha as leading the beings to enlightenment by first sowing the seed of enlightenment by preaching them the Lotus Sūtra, then bringing it to maturity, and finally reaping the harvest of liberation, a process transpiring over successive lifetimes. Nichiren makes explicit that it is always the Lotus Sūtra that sows the initial seed. While people in the True and Semblance Dharma ages might have progressed spiritually and even reached the maturity of full enlightenment through other teachings, this was only because they had first received the seed of Buddhahood by hearing the Lotus Sūtra in prior lifetimes. This idea also occurs in certain medieval Tendai texts attributed to Saichō, and it is possible that Nichiren’s emphasis on the seed of Buddhahood reflects more general developments within the broader field of contemporary Lotus Sūtra interpretation. However, Nichiren’s reading is distinctive in that it identifies the seed of Buddhahood as the daimoku (“All Buddhas of the three time periods and ten directions in variably attain Buddhahood with the seed of the five characters Myōhōrenge-kyō”) or as the “three thousand realms in one thought-moment.” Nichiren also connects the notion of the seed of Buddhahood specifically to the Final Dharma age. People in this age, he claims, have never before received this seed in prior lifetimes; they are people “originally without good [roots] ” (honmi uzen):

At this time, Namu-Myōhō-Renge-Kyō of the “Fathoming the Lifespan” chapter, the heart of the teaching of origin, should be planted as the seed [of Buddhahood in the minds] of the two kinds of persons who inhabit this defiled and evil age–those who commit the [five] perverse [offenses] and those who slander [the True Dharma].

(Page 270-271)