Zhiyi taught that the four doctrinal teachings were combined like ingredients into five different flavors of Dharma. The perfect teaching by itself was the best, but other flavors and periods made concessions to those who were not ready for the perfect teaching by combining it with other teachings, or in the case of the Deer Park period excluding it altogether. While Zhiyi believed that the Buddha used these different flavors throughout his fifty years of teaching, he also indicated that certain sūtras exemplified particular flavors. The seventh century Tiantai patriarch and reformer Zhanran later identified these flavors and their corresponding sutras more rigidly with a chronological scheme of the Buddha’s teachings called the five periods. In Treatise on protecting the Nation, Nichiren provides citations from various sūtras to justify this time scheme of the five periods. These five flavors or periods were then made to correspond to certain analogies used in the sūtras. One analogy comes from the Nirvāṇa Sūtra and relates the teachings to milk and its products – cream, curds, butter, and clarified butter. This analogy was Zhiyi’s inspiration for the five flavors. Another analogy relates the teachings to the process by which an estranged son is reconciled with his father and given his birthright as related in the parable of wealthy man and his poor son in the fourth chapter of the Lotus Sūtra. Yet another analogy comes from the Flower Garland Sūtra and relates the teachings to the progression of the sun from dawn to high noon.

1. The Flower Garland – This lasted for the first three weeks after the Buddha’s awakening and as such was not perceived by anyone but the gods and advanced bodhisattvas. This period combines the perfect teaching with the specific teaching. This means that while the Flower Garland Sūtra presents the final goal of Buddhism, many parts are aimed only at the bodhisattvas and so exclude those who do not share their aspirations or insight. This period is compared to fresh milk before it undergoes any further refinement; or to the time when the prodigal son is frightened to death by the magnificent wealth and power of the father whom he has forgotten; or the sun at dawn that illuminates only the highest peaks of the mountains.
2. The Deer Park – for the next twelve years beginning with the Deer Park discourse, the Buddha exclusively taught the tripiṭaka doctrine for the śrāvakas. At this stage the Buddha taught the four noble truths and the twelvefold chain of dependent origination in order to free people from worldly attachments and to overcome self-centeredness. This period is compared to the cream derived from milk; or the time when the father sends servants to employ the son for menial labor and later visits the son dressed as a fellow worker; or the sun when it has risen high enough to illuminate the deepest valleys.
3. The Expanded (Vaipulya) – for the next eight years the Buddha taught preliminary Mahāyāna teachings in order to castigate the śrāvakas for their complacency and to inspire the novice bodhisattvas by teaching the six perfections, the emptiness of all phenomena, and the existence of the buddhas in the pure lands of the ten directions. The Vimalakirti Sūtra, the three Pure Land sūtras, and those pertaining to Consciousness-Only and later the esoteric teachings are all lumped into this catch-all category which contains all four teachings by content that are taught depending on how they correspond to the needs of the audience at any given time and place. This period is compared to the production of curds; or the time when the son and the father develop mutual trust and the son enters his father’s mansion freely on business; or the sun at breakfast time.
4. The Prajña or Perfection of Wisdom (Prajña-pāramitā) – for the next twenty-two years the Buddha taught the Perfection of Wisdom sūtras which included the common, specific and perfect teachings, but not the tripiṭaka teachings. This period emphasized the emptiness of all phenomena and negated all the distinctions and dichotomies set up in the previous teachings so the way would be clear for the Buddha’s ultimate teaching in the following period. This period is compared to the production of butter; or the time when the father entrusts the son with his storehouses of gold, silver, and other treasures; or the sun late in the morning.
5. The Lotus and Nirvāṇa – in the last eight years of the Buddha’s life he taught only the unadulterated pure teaching in the Lotus Sūtra and reiterated it in the Nirvāṇa Sūtra. This was the period which not only comes full circle back to the Buddha’s own point of view but brings along all those who were gradually prepared by the last three periods and who did not understand or felt left out of the sudden teaching of the Flower Garland period. In this teaching the eventual attainment of buddhahood by all beings and the timeless nature of the Buddha’s awakening are affirmed. This period is compared to the production of clarified butter or ghee; the time when the father reveals that he is the son’s true father and bestows all his wealth upon the son; or the sun at high noon.

1. The Sudden Method – the Buddha teaches directly from his own awakening without any preliminaries. This is usually identified with the Flower Garland Sūtra. The Flower Garland Sūtra, however, is more of a presentation of the Buddha’s awakened state than a discursive teaching by the Buddha.
2. The Gradual Method – the Buddha begins at a very basic common-sense level and then gradually cultivates the understanding of his disciples. Beginning with the tripiṭaka teachings, the Buddha gradually introduced Mahāyāna teachings up to and including the Perfection of Wisdom sūtras. In this way, the disciples’ understanding, and aspiration matured until they could appreciate and benefit from the Buddha’s highest teaching in the Lotus Sūtra. The Lotus Sūtra itself is held to transcend any of the four methods because it is the goal of all of them.
3. The Secret Method – the Buddha teaches some people who can benefit by a specific teaching, but others are not aware of this because they are not ready and would misunderstand or even misuse the teaching. For instance, the Buddha might give advanced teachings on emptiness to bodhisattvas unbeknownst to the śrāvakas who might misinterpret it as nihilistic if they were to hear it.
4. The Indeterminate Method – the Buddha teaches one doctrine but the various people who hear it understand it in different ways. For instance, the four noble truths might be taught and understood by śrāvakas as referring to existing states of suffering or liberation that actual beings can reside. Bodhisattvas, however, would understand that the four noble truths lead beyond grasping at existing states and that no actual beings reside anywhere outside of the interdependent flow of causes and conditions.

The Tripitaka Teaching this corresponds to pre-Mahāyāna teachings as found in the Chinese Āgamas or the Pāli Canon and is directed to the śrāvakas (voice-hearers) who strive to become arhats (those who escape from this world of birth and death and do not return). It emphasizes emptiness and approaches it through analysis of the aggregates and the links of dependent origination. In other words, this teaching aims to reveal the emptiness of the self by examining the components of existence such as the five aggregates of form, feeling, perception, mental formations, and consciousness. It is shown that each of these is impermanent, subject to suffering, and cannot be the basis of an abiding independent self either alone or together. The links of dependent origination reveal the succession of causes and effects that make up existence and likewise reveal that an abiding self cannot be found therein. By doing this, the śrāvakas will realize the contingent nature of the self and thereby extinguish greed for what could satisfy the “self,” anger in regard to what threatens such a “self,” and ignorance regarding the selfless nature of the aggregates. In this way they will realize nirvāṇa and free themselves from birth and death. It might be asked: “What are the aggregates if they are not a self?” Do they somehow exist in their own right in some manner? And who is it that is free of birth and death and who enters nirvāṇa if there is no self? These are questions that are taken up in the following teachings.

The Shared Teaching — this corresponds to the Perfection of Wisdom sūtras and is directed to the more advanced śrāvakas and those just starting out on the bodhisattva path. Because these teachings are directed at both śrāvakas and bodhisattvas it is called the teaching they share in common. This level of discourse approaches emptiness more immediately or intuitively because it does not involve analysis. Rather, one learns not to impute substance or a fixed nature onto things in the first place. It is also more thoroughgoing in its application of emptiness in that it applies it not just to the self but also to all dharmas (phenomena). In answer to the above question, the aggregates not only do not provide a self either together or in part to an individual, but they themselves have no abiding substance or fixed nature. Each aggregate depends upon causes and conditions, which are also dependent on causes and conditions and so on ad infinitum. Emptiness in this teaching is the emptiness of any fixed nature or substance whatsoever. In response to the question as to who is saved, this teaching asserts that the bodhisattvas vow to save all sentient beings but do not cling to the idea that there are beings at all. It is all an empty show, but a show manifesting suffering or liberation depending upon the flow of causes and conditions. The question might then be asked: “How should bodhisattvas deal with causes and conditions if they know that they are all ultimately empty and have no basis, origin, or goal and no real self or entity abides anywhere?”

The Distinct Teaching — this corresponds to the Flower Garland Sūtra that is directed specifically to those who are firmly established bodhisattvas, so it is distinct from the teachings for śrāvakas. At this point, one needs to see that emptiness is not a dead-end but just the beginning. This requires an appreciation for contingent phenomena and thus the truth of provisional existence. While continuing to recognize that all things are empty, the bodhisattvas also see that this emptiness is not a blank void or nothingness. Rather, the lack of a fixed or independent nature is what allows all things to flow and move, change and grow, and ultimately interrelate so thoroughly that all things affect all other things like a web that quivers all at once when any one strand is touched. All things, all beings, are provisional manifestations of this interpenetrating dynamic process. Realizing this, bodhisattvas negate the negation of emptiness. They are free to reengage the world and appreciate all things without clinging or attachment. Gradually they realize the Middle Way that integrates peaceful detachment with compassionate involvement. Zhiyi called the empty, the provisional, and the Middle Way aspects of reality the threefold truth. In this teaching they are approached dialectically. Emptiness is the thesis, provisional existence is the antithesis, and the synthesis is the Middle Way. This is not the final teaching however, because an even greater integration lies ahead. Finally, one might ask: “If the tripiṭaka and shared teachings negate the self and all phenomena, and the distinct teaching negates that negation, is there any explicitly affirmative teaching in Buddhism at all?”

The Perfect Teaching — this corresponds to the Lotus Sūtra and the Nirvāṇa Sūtra and it is considered perfect or well rounded (the Chinese character used for this teaching holds both meanings) because it presents the integration of all three truths — the empty, the provisional, and the Middle Way — into a seamless whole. Each of these, if properly understood, immediately leads to an understanding of the other two in this teaching. For instance, what is empty is provisionally existent and therefore exemplifies the Middle Way. While the earlier teachings negate the world of birth and death through an analytical or intuitive approach to emptiness or negate a one-sided emptiness by affirming the provisional existence of all things; the perfect teaching affirms the total unity of the threefold truth of the empty, the provisional, and the Middle Way. In this teaching, the affirmative aspects of the earlier negations are made explicit. Negative and limiting aspects are emptied, positive and boundless phenomena are provisionally affirmed, and all manifests the liberation of the Middle Way. For instance, previously the vehicles of the śrāvakas and pratyekabuddhas (privately awakened ones) were condemned in favor of the bodhisattva vehicle, but now all the provisional vehicles are shown to be none other than the unfolding of the One Vehicle leading all to buddhahood. In previous teachings the historical Śākyamuni Buddha was shown to be a finite provisional manifestation of the cosmic principle of buddhahood that is sometimes personified as a cosmic buddha named Vairocana who is said to transcend birth or death. The Lotus Sūtra, however, portrays Śākyamuni Buddha himself as the one who reveals the unborn and deathless nature of buddhahood through his timeless spiritual presence and skillful activity. Previous teachings compared and contrasted the empty, the provisional and the Middle Way, but here the intrinsic unity of the freedom of emptiness, the creative responsiveness of the provisional, and the sublimity of the Middle Way is fully revealed.

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.