Scholars disagree about when the dispute over the precepts began. One scholar has suggested that Saichō may have been influenced by some of Dōchū’s disciples who, following Chien-chen’s teachings, called for a more open Buddhist order. Others have suggested that on his trips to Kyushu and Tōgoku, Saichō may have gone to see the kaidan (precepts platforms) in these two areas, and thus may have been considering reforms as early as 814. Neither of these theories has been proven.

The dispute began in earnest with Saichō’s efforts to have the court designate his monastery, Hieizanji, a Mahāyāna temple. On the seventh day of the second month of Konin 9 (late 817) Kōjō reports that Saichö told him that he wanted “to establish a Mahāyāna temple in order to propagate the (Tendai) School.” Kōjō seems to have been surprised by Saichō’s statement. According to Kōjō’s Denjutsu isshinkaimon, the following conversation took place:

The disciple (Kōjō) said, “There are no Mahāyāna temples in Japan. Why must we now suddenly establish a One-vehicle temple (ichijōji)?”

Our late teacher (Saichō) said, “I will bestow on you the title ‘One-vehicle (ichijō)’.”

His disciple (Kōjō) said, “Since there are no Mahāyāna temples in Japan yet, I will not take the One-vehicle title. Please bestow it on me after we establish a Mahāyāna temple.”

Our late teacher said, “In India there are purely Mahāyāna temples, purely Hinayāna temples and mixed (Mahāyāna and Hinayāna) temples.”

His disciple said, “If these three types of temples exist, then I ought to take the title. Temples are, after all, only places where monks reside.”

At this time, no mention was made of precepts. Exactly what the term ‘Mahāyāna temple’ or ‘One-vehicle temple’ designated and how such an institution would differ from the temples in Japan at that time is not specified in the conversation. Probably it was the beginning of an attempt by Saichō to develop a monastic institution which would embody, in a practical way, the issues being debated with Tokuitsu. If the court had recognized Saichō’s claim that Hieizanji was a Mahāyāna temple, it certainly would have enhanced the reputation of the Tendai School at the expense of the Hossō and Sanron schools by implying that they did not have purely Mahāyāna temples.

The Buddha-nature was a controversial topic in India, China and Japan. In his classic study of the long history of these disputes, Tokiwa Daijō (1870-1945) argued that the debate between Saichō and Tokuitsu represented the culmination of the disputes over the Buddha nature. The issues were probably more clearly demarcated and discussed by both men than at any other time in East Asian Buddhist history. Many new issues were introduced into the debate and their relation to the subject of the Buddha-nature investigated. Saichō displayed considerable ingenuity and an impressive command of Buddhist literature in drawing upon a variety of sources to formulate and defend his position. At the same time, the debate with Tokuitsu prepared the ground for the controversy over the bodhisattva precepts (bosatsukai) by indicating that the Tendai and Hossō positions were irreconcilable. Saichō’s petitions concerning the bodhisattva precepts … represent his attempt to formulate practices which would reflect the more theoretical statements which he had advanced in his works criticizing Tokuitsu.

[Page 90-91] The turning point in Saichō’s career began with a trip to Tōgoku (Eastern provinces) in 817. … During his travels in Tōgoku, Saichō probably heard about the Hossō Monk Takuitsu. … [Page 96] The dispute between Saichō and Takuitsu covered a wide range of problems, including the proper method of classifying the Buddha’s teachings, the evaluation of Tendai methods of exegesis of the Lotus Sūtra, and the criticism of various Tendai doctrines and meditations. Both men offered detailed and penetrating arguments in support of their positions. …

[Page 105-106] In its later stages, the debate focused on the exegesis of the Lotus Sūtra, the most authoritative scripture for the Tendai School.

Saichō often referred to his own school as the Tendai Hokkeshū, the Tendai School of Lotus Sūtra interpretation. It was not the only school which interpreted the Lotus Sūtra, since both the Hossō and Sanron schools had long traditions of exegesis of the Lotus Sūtra. Thus Saichō’s task was to show that the Tendai interpretation was the most authoritative one.

Tokuitsu followed the orthodox Hossō interpretation, as it was presented in Tz’u-en’s (632-682) commentary, the Fa hua hsüan tsan. According to Tz’u-en’s writings, the Buddha had a hidden purpose in preaching the Lotus Sūtra. He wanted to encourage people of undetermined nature to strive to become bodhisattvas, rather than being content with merely becoming or striving to become arhats or pratyekabuddhas. The One-vehicle doctrine was an expedient teaching (gonkyō) directed toward those of undetermined nature. The claims of the Lotus Sūtra that it was the ultimate teaching (jitsukyō) were an expedient designed to encourage this particular class of practitioner and were not to be considered as teachings which were universally valid. Predictions in sūtras that certain people would attain Buddhahood were said to refer to the individual’s possession of the gyōbusshō and to not have any general significance. Statements that all beings had the Buddha nature, such as that by the bodhisattva Jōbukyō (Never-disparaging), were said to refer only to the inactive ribusshō.

In contrast to the Hossō position presented above, Saichō believed that the Lotus Sūtra was the Buddha’s ultimate teaching, a direct revelation of the Buddha’s enlightenment, which was valid for all men and not just intended for one particular group. Saichō supported his arguments by referring to passages in the Lotus Sūtra that stated that the sūtra was indeed the Buddha’s ultimate teaching, by defending the Tendai classification of Buddhist doctrine, and by attacking the Hossō classification of Buddhist doctrine. The defense and exegesis of the The teachings of the One-vehicle, the universality of salvation, and the speedy realization of salvation were eventually accepted as standard Buddhist teachings throughout Japan. The new schools of the Kamakura reformation developed out of the Tendai School and adopted the positions that Saichō had defended, though not without changes. Even some Hossō monks such as Ryōhen (1194-1252) tried to reconcile the differences between Hossō and Tendai by devising positions which allowed for universal salvation and the quick attainment of salvation.

The Tendai School had a more optimistic view of human potential than did the Hossō School. Tendai monks followed the Lotus Sūtra in arguing that all sentient beings could eventually attain Buddhahood. No beings were permanently denied Buddhahood. They also argued that the three vehicles did not lead to three separate ultimate goals. Rather, all sentient beings had only one ultimate spiritual goal, Buddhahood. Teachings leading the practitioner to arhathood or pratyekabuddhahood were only provisional teachings designed to encourage those with lesser faculties and lead them onward towards the single ultimate goal for all sentient beings, Buddhahood.

On the basis of these Tendai teachings, Saichō argued that only sūtras which presented provisional teachings contained claims that some people could attain Hinayāna goals but could never attain Buddhahood. The five types of human nature which the Hossō School had presented did not refer to seeds from the beginningless past, but to stages which a practitioner might attain and then transcend as he moved onward to higher goals. The five types of human nature were not determined by seeds which sentient beings possessed from the beginningless past, but by the obstacles which men had to overcome on their way to Buddhahood.

The Hossō School’s position was that two categories of Buddha nature could be identified: the ribusshō, which all men possessed, and the gyōbusshō, which only a few possessed. The first was the Buddha-nature as absolute. Since the absolute was the basis of all phenomena, and since all sentient beings were ultimately dependent on the absolute, all were said to possess the ribusshō. However, Hossō scholars argued that the absolute was static; it did not actively participate in the phenomenal realm. Consequently, the ribusshō did not enable a practitioner to attain Buddhahood. When a sūtra stated that all sentient beings possessed the Buddha-nature, it indicated only that all had the ribusshō, not that all could attain Buddhahood.

The potential of some sentient beings to attain Buddhahood was explained by postulating a second type of Buddha-nature, the gyōbusshō or Buddha-nature of practice. The gyōbusshō consisted of untainted seeds (muro shuji) which were stored in the eight or basic consciousness (arayashiki, Skt. ālaya-vijn͂ana). These seeds were said to have existed from the beginningless past. If a person possessed them, he could attain Buddhahood. However, if he lacked untainted seeds, he could not create them no matter how diligently he practiced or studied. A person without the gyōbusshō could therefore never attain Buddhahood. Hossō School monks interpreted statements in the sūtras that only certain people could attain Buddhahood as referring to the possession of gyōbusshō by those people. Since not everyone had the gyōbusshō, some sūtras contained statements that not everyone could attain Buddhahood.

The small amount of reliable information that survives about Saichō’s teacher Hsing-man is found in Saichō’s Kechimyakufu. Hsing-man, a native of Su-chou (in modern Kiangsu), was initiated when he was twenty and ordained as a monk when he was twenty-five. He studied the Ssu fen lü precepts for five years. In 768 he met Chan-jan and attended a number of his lectures on Chih-i’s major works (Tendai sandaibu). At the time of Saichō’s arrival in China, he was the head of the Fo-lung temple on Mount T’ien-t’ai. Hsing-man encouraged Saichō in his studies, giving him eighty-two fascicles of T’ien-t’ai works. He also told Saichō that Chih-i had predicted that a foreign monk would come to China in order to propagate T’ien-t’ai teachings in a country to the east of China. Predictions such as this one probably helped foreign monks such as Saichō and Kūkai gain ready acceptance by Chinese monks. Hsing-man assiduously practiced religious austerities and authored a number of works. He died around the year 823 when he was over eighty years old.

In his petition asking that students be sent to China, Saichō claimed that the Tendai texts transmitted to Japan contained many copyist errors. In addition, a direct transmission from Chinese teachers to Japanese students was needed to insure the orthodoxy of the Tendai School in Japan. Saichō criticized both the Hossō and Sanron schools for being based on Sāstra (commentaries), not on sūtras (the Buddha’s words). Hossō and Sanron monks considered only the branches of the Buddha’s doctrines and neglected the roots. Tendai teachings, because they valued the Lotus Sūtra above all other authorities, were not subject to this criticism. Thus even before he went to China, Saichō declared his intention to establish the Tendai School in Japan.

The Lotus Sūtra (Tno. 262) in its translation by Kumārajīva done in 406 was the most popular single sūtra during the Nara period. It was required that all yearly ordinands be able to read it. It is the most commonly mentioned sūtra in documents recommending laymen for ordination as monks. … The Lotus Sūtra was also frequently recited at the request of the court in order to protect the state. It does not have any specific passage which guarantees protection of the state, as did most of the other sūtras used for this purpose. Rather, this use of the sūtra stems from its claim that it is the most authoritative of all sūtras and from stories that those with faith in the sūtra were protected from harm. In addition, it was a very popular sūtra among the common people, being the sūtra most often mentioned in the Nihon ryōiki.

One of the distinguishing characteristics of Buddhism during the Nara period (710-784) was the lavish expenditure of money by the state for temples, Buddhist images, and the copying of Buddhist texts. The merit from such activities was often devoted to the protection of the state and its ruler from various catastrophes. Records of Buddhist activities during the Nara period reveal that the ceremonies performed and the sūtras chanted were often directly related to state Buddhism. The establishment of a nationwide system of provincial temples (kokubunji) with the Tōdaiji temple at Nara as its center is one of the crowning achievements of state Buddhism at this time. Buddhism was thus used to integrate the provinces and the capital.

Qualified monks were required to keep the system functioning. The monks had to be able to chant the sūtras which would protect the state. They also were expected to have led a chaste life so that they could accumulate the powers for the ceremonies to be effective. In order to ensure that the men who joined the Buddhist order were able to perform these ceremonies, the court established requirements which candidates for initiation as novices or ordination as monks had to meet. According to an edict issued in 734, a candidate for initiation was required to be able to chant the Lotus Sūtra (Fa hua Ching, Skt. Saddharmapuṇḍrikasūtra) or the Sūtra of Golden Light (Chin kuang ming Ching, Skt. Suvarṇaprabhāsasūtra), to know how to perform ceremonies worshiping the Buddha, and to have led a chaste life for at least three years. The requirements were designed to ensure that the candidate would be able to effectively perform religious ceremonies. Little attention was paid to the candidate’s ability to explain Buddhist doctrine. If a candidate met the requirements, he would be initiated at the court at the beginning of the year, with the merit resulting from his initiation devoted to the welfare of the state. Successful candidates were called “yearly ordinands.”