Before Zhiyi there had been a lot of debate about the true meaning of the Buddha’s teachings due to the contradictions found between the various sūtras and commentaries coming from India. Starting in the late fifth century, various attempts were made to reconcile the many teachings that were being translated. By Zhiyi’s time there were the so-called three schools of the south and seven schools of the north that each presented a different system for classifying the sūtras. These were not schools in the sense of sects or monastic orders, but rather differing schools of thought propounded by different monks. These schools arranged the sūtras into such categories as sudden, gradual, and indeterminate. Many of these schools favored the Flower Garland Sūtra or the Nirvāṇa Sūtra as the ultimate teaching of the Buddha.

Zhiyi critiqued these systems and presented his own system in the Profound Meaning of the Lotus Sūtra of the five flavors and eight teachings that showed how the teaching and practice of the other sūtras all led up to the Lotus Sūtra as the definitive expression of the Buddha’s ultimate teaching. This is what Nichiren is referring to in the following passage of the Kaimoku-shō:

The Buddhist texts, however, created three sects in South China and seven sects in North China. The controversies among them were furious. In the end, they were defeated by [T’ien-t’ai] Chih-che in the Ch’en (Chi) and Sui (Zui) dynasties. Accordingly, the priests of the ten sects stopped quarreling and resumed their mission to save the people. (Murano 2000, p. 16)

In the sixth century, the Chinese monk Zhiyi (538-597) established a teaching center on Mt. Tiantai. He was later known as the Great Master Tiantai, founder of the school of the same name. Zhiyi was a great scholar and meditator who wanted to systematize all the seemingly contradictory teachings that had been translated into Chinese. To do this, he classified the Buddha’s teachings into five flavors and eight categories of teaching. As a practitioner, as well as a scholar, he put equal emphasis on meditation practice and doctrine in order to create a balanced system whereby doctrine would inform practice and practice would actualize doctrine. The concept of the “three thousand realms in a single thought-moment” … was part of his explanation of the sudden and perfect method of tranquility and insight meditation. He also spoke of awakening in terms of realizing the unity of the threefold truth of emptiness, provisional existence, and the Middle Way in order to clarify the true meaning of the teachings of the Perfection of Wisdom sūtras and Nāgārjuna’s (second-third century) teachings regarding emptiness, causality, and the Middle Way. He derived the unity of the threefold truth from a line in Nāgārjuna’s major work, Verses on the Middle Way:

“Whatever is dependently co-arisen
That is explained to be emptiness.
That, being a dependent designation,
Is itself the middle way.” (Garfield, p. 304)

Zhiyi taught that the threefold truth could be realized through a “threefold contemplation” cutting through the “three categories of delusion” and giving rise to the “three kinds of knowledge.” Ultimately, Zhiyi taught that the three truths of the threefold truth are simply different aspects of the one true nature of reality that can be realized in a single moment of insight.

One would think that all Mahāyāna schools would recognize the ability of all people to attain buddhahood since they were based upon the Mahāyāna sūtras wherein the Buddha asserted at the beginning and the end of his teaching that all beings have the buddha-nature and are therefore capable of attaining buddhahood. In fact, the Mahāyāna sūtras did not always guarantee universal buddhahood for all beings. In particular, the arhats and pratyekabuddhas who attained the Hinayāna nirvāṇa were believed to be incapable of taking up the bodhisattva vehicle and attaining buddhahood, particularly since upon passing away they would never again be reborn in the six worlds or anywhere else. This is why Nichiren writes that, “The Hossō and Sanron schools established eight realms, but not ten. Needless to say, they did not know that the ten realms interpenetrate one another.” (Adapted from Murano 2000, p. 14) In other words, because the Dharma Characteristics and Three Treatises schools taught that the arhats and pratyekabuddhas have no realms of their own they simply become extinct upon their deaths and therefore these two schools only acknowledge eight of the ten realms. The Dharma Characteristics school also taught, based upon its own sūtras and commentaries, that people have one of five distinct natures: some people are incorrigible disbelievers (S. icchantika) who are incapable of ever leaving the six lower realms, some are capable of taking up the śrāvaka vehicle, some are capable of taking up the pratyekabuddha vehicle, some are capable taking up the buddha vehicle, and some are able to take up any one of the three vehicles. In this scheme there are some who will never escape saṃsāra and very few who can or will attain buddhahood. Even though these people may have buddha-nature as the true nature of their lives, they do not have the wisdom or virtue to ever realize it.

By introducing the bodhisattva vehicle with its six perfections, expounding the teaching of the emptiness of all dharmas, and providing the assurance that all beings have the buddha-nature the Mahāyāna sūtras advanced beyond the limited aspirations and world view of the Hinayāna teachings. According to Nichiren and his Tiantai predecessors, however, the Mahāyāna sūtras other than the Lotus Sūtra are only a provisional form of Mahāyāna with two important shortcomings.

The Flower Garland Sūtra, Large Perfection of Wisdom Sūtra, and the Mahāvairocana Sūtra conceal not only the possibility of attaining buddhahood by adherents of the two vehicles but also Śākyamuni Buddha’s attainment of buddhahood in the remotest past. These sūtras have two faults. First, they still preserve the differences between the three vehicles; therefore, their teachings are merely expedient. They do not reveal the teaching of the three thousand worlds in one thought moment expounded in the first fourteen chapters of the Lotus Sūtra. Second they hold that Śākyamuni Buddha attained Buddhahood during his life in this world. (Murano 2000, p. 32 adapted)

The perfection of wisdom is the ability to deal with the conventional truth of the ordinary common-sense way of relating to the world as a multiplicity of persons, places, and things and at the same time be awakened to the ultimate truth that all things, all dharmas, are empty. This does not mean that things do not exist at all. That is not what “emptiness” means. Emptiness is another way of talking about how things that are caused and conditioned do not have an unchanging, independent self-nature. It is a deeper way of contemplating dependent origination that points to the flowing, composite, conceptual nature of the things that we experience. Things are empty because they are impermanent. So there is nothing to be permanently grasped. Things are empty because they are composite. So apart from the components (causes and conditions that are all in turn caused and conditioned ad infinitum) there is nothing to grasp. Things are empty because they are not what they seem to be as a result of our mind projecting categories and concepts onto the dynamic interdependent flow of causes and conditions. Apart from our mental concepts there is no singular thing to be grasped in the flow of causes and conditions. Emptiness is not meant to be a theory or belief that we should just subscribe to conceptually. It is meant to be something to observe directly by deeply contemplating the flowing, composite, and conceptual nature of phenomena. Emptiness is not so much a characteristic as a way of pointing out that things are not the solid permanent independent facts they seem to be. Nevertheless, they are contingent realities. By realizing that all things are empty, bodhisattvas overcome undue attachment towards them and also overcome any undue aversion towards them. Free of attachment and aversion, bodhisattvas deal with phenomena in a more graceful, fearless, and wholesome way. They can care about and deal with conditioned phenomena without falling into the trap of craving certain conditions and fearing others. This includes craving or fearing anything within the six lower realms, or even the peace attained in the higher realms of the two vehicles. This is why the perfection of wisdom is synonymous with skillful means and is the spirit that unites and guides the other five perfections.

According to the Lotus Sūtra, the Buddha specifically taught the six perfections for the bodhisattvas. “To bodhisattvas, he expounded the teaching of the six perfections, a teaching suitable for them, and caused them to attain perfect and complete awakening, that is, to obtain the knowledge of the equality and difference of all things.” (Murano 2012, p. 14) It is the six perfections that differentiate the bodhisattva vehicle from the other two vehicles. The knowledge of the equality and difference of all things refers to the ability of the perfection of wisdom to deal both with the ultimate truth of the universal quality of emptiness and also the conventional truth that recognizes the different characteristics of conditioned phenomena in their transience and interrelationships.

The perfection of meditation (S. dhyāna) is a development of right concentration (S. samādhi) of the eightfold path. Meditation in a state of bliss without discriminating thought refers to the second through fourth of the four dhyānas (states of increasingly refined meditative absorption) wherein discursive thought has been transcended. One way of entering into the dhyānas would be through contemplating the four infinite virtues of lovingkindness, compassion, sympathetic joy, and equanimity and extending those feelings in one’s regard to all beings in all directions. From the fourth dhyāna one might also cultivate the four attainments that are increasingly subtle formless objects of contemplation: space, consciousness, nothingness, and neither perception nor non-perception. It is taught in Buddhism that entering any of these states creates the karma to be reborn into a corresponding heaven. The bodhisattva, however, does not practice meditation for the purpose of attaining a heavenly rebirth or to selfishly abide in such pleasant states. Instead, meditation is used to overcome the hindrances of sensual desire, ill-will, drowsiness, agitation, and debilitating doubt. Meditation is also the optimum way of developing the aforementioned four infinite virtues and other wholesome qualities with which to help sentient beings. Finally, meditation provides the calmness and clarity of mind that allows for the insight into the true nature of reality. All of this is cultivated for the sake of all beings, but again without holding onto any of these states as an object of attachment or aversion.

The perfection of energy is the bodhisattva’s tireless efforts to work for the liberation of all beings. It is like armor, because with it the bodhisattva is protected from any obstacles and will not fall prey to the lesser goals of the two vehicles. Like right effort of the eightfold path, the perfection of energy is about preventing the arising of unwholesome states, abandoning those that have arisen, generating positive states, and maintaining positive states that have arisen. Unlike right effort, the perfection of generosity is specifically dedicated to the benefit and liberation of all beings and again the bodhisattva does not hold the idea that either the unwholesome or the wholesome qualities have any essential nature to accept or reject. In this way the bodhisattva is without any undue anxiety over negative states or conceit over positive ones, they simply work unselfconsciously to assist all beings on the path to awakening.

The perfection of patience is of course about being patient when suffering setbacks in life, physical or emotional harm, or even malice from other beings. They overcome anger and ill-will through their compassion and the insight that in the interplay of causes and conditions there is nothing ultimately personal about any of the injuries suffered. Again, this perfection is perfected as the bodhisattva overcomes attachment and aversion and the idea that there are ultimately real beings and objects to grasp or reject. The bodhisattva must also be patient with the Dharma itself. The teaching that all things are empty of any self-nature or essence can be quite disconcerting, and its subtleties are hard to understand. The bodhisattva must patiently continue to contemplate the perfection of wisdom until they see that in fact no unchanging independent essence can be found amidst causes and conditions and that the unobstructed true nature of reality is the groundless ground (so to speak) of the liberated selfless compassion of buddhahood.