[In considering enlightenment in this body] Saichō … drew on the episode in the Lotus Sūtra of the eight-year-old nāga princess, who in the space of a moment changes into a male, completes the eight phases of a Buddha’s life, and manifests perfect enlightenment. In his writings, the realization of Buddhahood with this very body is linked not to esoteric practices, but to the power of the Lotus Sūtra. The nāga girl, Saichō points out, had a threefold hindrance: she was born into the animal realm as a nāga (a serpent or dragon), clearly the result of unfavorable karma; she was female and of poor faculties; and she was young and therefore had not been able to devote many years to religious practice. Nevertheless, through the wondrous power of the Lotus, she was able to attain Buddhahood. (Page 31-32)

Long before the emergence of Japanese Taimitsu, or even of esoteric Buddhism in East Asia, attempts had been made to identify Śākyamuni with the Buddha Vairocana, whose name is transliterated in Chinese versions of the sūtras as either Lu-che-na (Jpn. Rushana) or P’i-lu-che-na (Birushana). Such identifications begin in the sūtra literature. The sixty-fascicle Hua-yen ching says that the names “Śākyamuni ” and “Vairocana” refer to the same Buddha. The Fo-shuo kuan P’u-hsien P’u-sa hsing-fa Ching (Sutra of the Buddha’s preaching on the method of contemplating Bodhisattva Samantabhadra), the capping sūtra to the Lotus, reads, “At that time the voice in space will speak these words [to the meditator]: ‘Śākyamuni is called Vairocana Pervading All Places, and that Buddha’s dwelling place is called Ever-Tranquil Light. The Fan-wang ching presents Vairocana as manifesting individual Śākyamuni Buddhas as his emanations in billions of worlds. Because he is said to have attained these powers as the reward of long efforts in cultivation, Vairocana in this depiction may properly be regarded as a recompense body (saṃbhogakāya, hōjin)—the wisdom and supernatural attainments of a Buddha achieved through practice, imagined as a subtle body.]

Chinese commentators advanced various theories about the relationship of these Buddhas, often in connection with discussions about the various kinds of “bodies” that Buddhas were said to possess. Chih-i, for example, citing various sources, identified P’i-lu-che-na as the Dharma body, Lu-che-na as the recompense body, and Śākyamuni as the manifested body—noting, however, that the three bodies were inseparable. Elsewhere, in a dynamic synthesis, he interpreted Śākyamuni Buddha of the “Fathoming the Lifespan” chapter as embodying all three bodies in one. When the Buddha’s wisdom grasps the ultimate reality, that which is realized is the Dharma body; and the wisdom that realizes it is the recompense body. For the sake of living beings, this wisdom manifests itself in physical form as human Buddha who teaches in the world; this is the manifested body. Since the recompense body both realizes the truth that is the Dharma body and responds to aspirations of the beings in the form of the manifested body, Chih-i regarded it as central. However, he also rejected any notion of hierarchy among the three bodies, denying that one can be seen as prior to the others. (Page 25-26)

The Buddha of the Lotus Sūtra appears in that text in two forms. First he is presented simply as the historical Buddha, Śākyamuni, who attained enlightenment at the age of thirty under the Bodhi tree. But the eleventh chapter suggests that he is more than this: all Buddhas in the worlds of the ten directions are shown to be his emanations. This foreshadows the dramatic revelation of the sixteenth chapter, called “Fathoming the Lifespan of the Tathāgata” (Nyorai juryō-hon), in which Śākyamuni declares that countless myriads of kalpas have passed since he attained Buddhahood, and that ever since then, he has been constantly in this world, preaching the Dharma in various guises and by various skillful means. Chih-i had divided the sūtra into two parts of fourteen chapters each, according to these two presentations of the Buddha. The first fourteen chapters, called the “trace teaching” (shakumon), present the Buddha as a “manifest trace” (suijaku) or historical appearance, while the latter fourteen chapters, called the “origin teaching” (honmon), present him in his original ground (honji) as the Buddha who first attained enlightenment in the inconceivably remote past. (Page 24)

[A]mong Saichō’s later followers, the traditional T’ien-t’ai “perfect teaching” (engyō) based on the Lotus Sūtra was fused with Mikkyō in the “one great perfect teaching.” Their writings recapitulate Saichō’s move to incorporate all teachings within the Lotus, but in esoteric terms. That is, rather than encompassing Mikkyō within the framework of the one vehicle of the Lotus as Saichō had intended, Taimitsu developed an esoteric reading of the one vehicle that tended to subsume the Lotus within Mikkyō, a tendency especially evident in Annen’s writings. In any event, the two traditions became inseparably intertwined and came to share a common vocabulary. Medieval Tendai hongaku thought would emerge in large part as an attempt to reinterpret traditional T’ien-t’ai/Tendai doctrines through the lense of an esotericized sensibility. (Page 24)