As we have seen in the previous chapters, the Buddha's awakening consists in perceiving the true aspect of things and in order for all ordinary beings to achieve the same state of liberation life, the first expression he used to show that things are not produced by the will of a God, nor by chance, nor by destiny, he taught the principle of "conditioned production" (engi - 縁起) which means that things are the effect of causes and conditions. For example, the painting called "Mona Lisa" is the work of Leonardo da Vinci. To execute it, he used a canvas, colours, brushes, his talent and dexterity did the rest. But if it had been Raphael, who lived at the same time, who had used the same support, the same colours and the same brushes, he could have painted his famous self-portrait and the work would have been completely different. The Mona Lisa, like Raphael's self-portrait, is a conditioned production and therefore has no nature of its own. Having no nature of their own, the characteristic of these paintings is emptiness. Lack of proper nature (mujishō - 無自性) and emptiness (kū - 空) are the logical and subsequent development of conditioned production.

However, having reached the sutras of the Great Vehicle, the Buddha taught that although emptiness represented the true aspect, it was, at this stage, only a partial truth, to which he added the truth of conditionality implying that things exist as objects of our perception. Finally, having reached the wisdom sutras, he taught medianity. The truth of the middle represents the true principle that does not attach to the two extremes of emptiness and conditionality, but includes them both.

In other words, everything is empty because it exists only temporarily due to causes and conditions, and since there is no fixed body called emptiness, it can also be said that emptiness is also empty. Therefore, medianity denies both emptiness and conditionality, while establishing emptiness and conditionality together, which is also called the truth of the middle or the middle way.

This middle way is not a compromise between the two, but a truth that encompasses both emptiness and medianity.

Now, while in the sutras prior to the Lotus Sutra these three truths were taught separately, the great Tendai master Zhiyi determined that in the Lotus Sutra these three truths were in fact one and the same 'triple truth'. The practice of observing this threefold truth in his heart (isshin sangan - 一心三観) led him to the awakening of the contemplation of three thousand realms in one thought. The doctrine of One Thought Three Thousand (ichinen sanzen - 一念三千) is the ultimate teaching of Buddhism, taught only in the Lotus Sutra, the goal of Shakyamuni Buddha's coming into this world and revealed by Zhiyi, the great master of the Tendai. To this end, in the spring month of April of his fifty-seventh year, in the temple called Yuquan-si (玉泉寺), in the province of Jing, he taught a book in ten fascicles, called the Great Halting and Contemplation, to his disciple, the great master Zhangan. It was only in the fifth fascicle of this treatise that he first declared:

"One Heart contains ten worlds of dharmas. Furthermore, each world of dharmas contains the ten worlds, making a hundred worlds. Each world in turn containing thirty domains, the hundred worlds, contain three thousand domains. These three thousand are present in the heart of a thought. If there is no heart, there is no need to go further. But if there is the tiniest bit of heart, it contains all three thousand. Moreover, it is not said that the heart precedes the infinity of dharmas, nor that the infinity of dharmas precedes the heart.

The elements that make up the principle of One Thought Three Thousand are the Ten Worlds expounded in the Flowery Ornament Sutra, the Ten Thus's expounded in the Lotus Sutra, and the Three Realms expounded in Nagarjuna's Treatise of Great Wisdom.

With regard to the Ten Worlds, let's do some etymology. The ideogram translated as world (界 - kai) is composed of two elements. The top one gives its meaning and the bottom one gives its pronunciation. The top part (田which is pronounced "ta" or "den") means "rice field". It is used in the formation of compound words for "land" (den'ya-田野 = cultivated field, or den'en - 田園 = rural area), which refers to the "countryside" (denka - 田家= rural house), a "place shaped like a rice field" (enden - 塩田= salt marsh), a "vast area where produce is harvested" (yuden- 油田= oil field, or tanden-炭田= coal basin).

Its shape symbolizes the dikes separating the rice fields and the cross-shaped part (十) symbolizes the paths along the rice fields and the paths connecting north to south and east to west.

As for the bottom part (介 which is pronounced "kai"), it represents (among other things) a man in armour or the fact of intruding into a space.

Etymologically, the word "kai" (界) thus refers to the border between two rice fields and means "dividing line", "proximity", "division", "the end of a sentence", "the boundaries". It is used in compound words such as those denoting a certain social sphere: 'the world of finance' (zaikai - 財界), 'the world of religion' (shūkyōkai - 宗教界).

In English, the word "kai" is translated as "realm".

In conclusion, the word "kai" represents a bounded place, completely distinct, partitioned from others. This is why I have chosen to translate it into French as "monde", in other words a place from which it is not easy to leave and where it is not easy to enter, at least during our life in this world, which it is impossible to modify.

These ten worlds are, I recall, the hells, the hungry spirits, the animals, the ashuras, the humans, the heavens, the auditors, the awakened by conditions, the bodhisattvas and the world of the Buddha.

Each world is composed of three elements, called 'domains' (seken - 世間). First, there is the domain of territory (kokudo seken - 国土世間). It is the physical, non-sentient place constituting the support of beings living in this world. It is also called the "receptacle domain" (ki-seken - 器世間). Thus, the red-hot iron is the dwelling place of the hell world. Hungry spirits live five hundred yojanas under the Janbu continent. Animals inhabit water, land and air, ashuras dwell in the shallow waters of the ocean, by the sea, humans inhabit the earth, the heavens dwell in the heavenly palaces, the two vehicles inhabit the Land of Means, the bodhisattvas inhabit the Land of Correct Retribution and the Buddhas inhabit the Land of Serene Light.

Then there is the realm of beings. These are the beings who live in each of the ten worlds. For example, beings living in the first of the eight great hells, called the hell of equal rebirths (Tōkatsu jigoku - 等活地獄), tear each other apart, or are torn apart by the guardians of the hell. Once they reach this stage, they are resurrected in the same hell, resuming their original appearance, in other words, they are reborn as they were at the time of their fall into hell.

Finally, the domain of the five shadows represents the physical and spiritual constituents of individual beings. These are form, perception, conceptualisation, reaction and consciousness. Each being is the provisional reunion of these five aggregates.

Each domain has an aspect, a nature, a substance, an energy, an action, a cause, a condition, an effect, a retribution, the whole consisting of the first, the aspect, to the last, the retribution. The latter is the retribution of the medium (ehō - 依報) for the realm of territory and the retribution of the principal (shōhō - 正報) for the realms of beings and the five aggregates. As we shall see later, there is non-duality between the support and the principal (eshō funi - 依正不二).

The three domains containing the ten Thus, give thirty domains, present in one world. Since there are ten worlds and these ten worlds contain each other, we get the figure of three thousand worlds, or three thousand domains or three thousand Thus's, depending on the order in which the demonstration is made. These three thousand are contained in the heart of One Thought.

Thus, the theory of One Thought Three Thousand, in its broad outline, is a doctrine that categorises and synthesises all existences, or all dharmas, into three thousand laws, and explains that these three thousand laws are all contained in the mind (heart) of every human being (this is then the relation of "what contains" (gu = 具) and, furthermore, that these three thousand laws are the heart of a single thought (this is then the relation of what is (ze = 是).

Let's review what we have seen above, in a little more detail according to Zhiyi's explanation. If we classify the entirety of the dharmas into three thousand categories, what procedure do we use to arrive at this number? First of all, the ten types of existence in the universe, including the subjective way of being of human beings (= the ten worlds, from hell to the Buddha world), mutually embody the other nine types of existence. In this sense, they form the Hundred Worlds. Each of these beings also follows the ten ways of being, which are related to the aspect etc., to the point of total equality from the origin to the end. Therefore, the total number of these ways of being is one hundred worlds and one thousand Thus. Furthermore, each of these beings has three types of existence. These are the three kinds of realms: the subjective aspect (the realm of sentient beings), the realm of mind and matter (the realm of the five aggregates), and the realm of the non-sentient environment (the realm of the territory). Thus, the hundred worlds and the thousand thus have three thousand kinds of domains. Thus we get the number of three thousand.

The three thousand dharmas are taken from the perspective of the basic elements of human beings and the world, such as the subjective ways of human beings, the composition of the environmental world around them and the expected place of existence of sentient beings, and they represent the number of substrates on which all dharmas are based.

The number three thousand therefore has great significance in the teaching tradition, but this does not mean that the entirety of the dharmas is quantitatively a collection of three thousand dharmas. To put it in an extreme way, three thousand might as well be five thousand. In short, three thousand is a quantitative description of the entirety of the dharmas presented in such a way as to maintain doctrinal coherence and which is clearly organised in the infinite variety of different aspects of the dharmas.

What is important in this doctrine, therefore, is not the number of all the dharmas classified as three thousand, but the relationship between the actual dharmas presented as three thousand and the minds of sentient beings. The most important part of this doctrine is that which reveals the relationship between the mind (the heart) and the wholeness of the dharmas, and the nature of the wholeness of the dharmas, which is stated as "the heart contains all the dharmas" and "the heart is all the dharmas".

It may be useful, in a way, to list what Zhiyi teaches on this point. Here are some representative passages of the explanation.

"One heart contains ten worlds, each world in turn containing ten worlds, this gives us a hundred worlds. One world also contains thirty kinds of realms, so that one hundred worlds of the dharmas contain three thousand kinds of realms. These three thousand are present in the heart of a thought.

"If the entirety of the dharmas arise from a heart, we speak of verticality. If the heart contains all the dharmas at the same time, then we speak of horizontality. Now, the mind is neither vertical nor horizontal, but the mind is the wholeness of dharmas, and the wholeness of dharmas is only the mind. Therefore, there is neither verticality nor horizontality, the heart and the dharmas are neither one nor different. It is mysterious, wonderful, profound and unparalleled. It is not what the mind perceives, nor what words say, and that is why it is called the inconceivable object (by the senses).

Thus, it is explained that the relationship between the mind and the wholeness of the dharmas is to be understood in terms of the relationship between 'having' (gu - 具) and 'being' (ze - 是), but what kind of questions concerning the wholeness of the dharmas and the mind does this doctrine attempt to express?

With reference to the other explanations given in the relevant passages of the Great Arrest and Contemplation, it seems to be a doctrine that tries to explain how everything that exists, including the mind, is not able to assert its own fulfilment and independence in the light of reality.

Let me give you some more details on this issue.

The infinity of all the dharmas classified into three thousand can manifest according to the viewpoint of the mind, just as the ten worlds arise in different ways according to the viewpoint of the mind which sees the entirety of the dharmas in different ways (this is the relationship between 'the mind generating all the dharmas').

Conversely, if we consider the possibility that the mind can be any of the ten worlds depending on how it views all the dharmas, as well as the fact that it can be any of the ten worlds, then it is possible to understand that the mind is imbued with the wholeness of the dharmas (this is the relationship of the 'heart imbued with the wholeness of the dharmas'. However, if we look more closely at the reality of all the dharmas, the mind and all the dharmas should not be understood in terms of an 'active-passive' relationship (nōsho-能所). In other words, understanding the relationship between the dharmas and the mind, namely that the mind produces (nōshō-能生) and implements (nōgu-能具) the wholeness of the dharmas, and that this wholeness of the dharmas is produced (shoshō-所生) and implemented (shogu-所具) by the mind, does not lead to a correct understanding of both. Therefore, what kind of understanding is correct?

It must be understood that neither the mind nor any dharma is in an isolated sphere, mutually denying the other. How can this be the case?

The reason is the unqualified nature of mind and all dharmas, i.e., it is impossible to assert one's own uniqueness in relation to the others, for "even if one searches for one's mind, it is impossible to know it, just as, even if one searches for the three thousand, it is impossible to know them."

Thus, the relationship between the mind and the wholeness of the dharmas is that "the mind is the wholeness of the dharmas" and "the wholeness of the dharmas is the mind", and both come out of the shell of their respective ways of being, are essentially autonomous, and stand in a truly "non-dual" relationship. This is the true form and way of being of all living things. The theory of One Thought Three Thousand is a doctrine that teaches the ultimate state of existence - that everything that exists cannot assert itself in a self-limiting way, distinguishing itself from others.

Furthermore, in the course of the many asceticisms Zhiyi engaged in, there are the "ten methods of contemplation". It was during the first of these methods, the "contemplation of the inconceivable object" (kan fushigi kyō - 観不思議境) that he awakened to the principle of One Thought Three Thousand. The means of contemplation he used is the "tetralemma of discernment (shiku funbetsu - 四句分別). The discernment tetralemma is a form of reasoning in which a four-proposition syllogism is used to examine the impossibility of apprehending the completeness of the dharmas, as taught in the theory of One Thought Three Thousand. Zhiyi's reasoning is not only based on the doctrine of One Thought Three Thousand, but also on the Four-Proposition Syllogism, which is in line with the teaching of Nagarjuna's "Treatise on the Middle", which examines the causal relationship producing what exists in the form of four points of view: birth caused by one's own substance, by the substance of another, by both (together) and without cause.

Let me give you an example of one of the forms of reasoning used by Zhiyi as a form of "tetralemma of discernment" (four proposition syllogism).

The following four propositions are set up from the example of a dream and proceed to confirm its existence. (i) Is the dream the fruit of the heart? (ii) Is the dream the fruit of sleep? (iii) Can the dream appear where the mind and sleep merge? (iv) Does the dream appear independently of the mind and sleep? In seeking to confirm the existence of the dream according to these four propositions, we come to the conclusion that the existence of the dream cannot be confirmed in any of them. This is the framework of the discernment tetralimma.

Zhiyi's doctrinal interest is fulfilled by the contemplation and realization of the true aspect of all dharmas, which is expressed through the theories of the threefold body and One Thousand Thought. From the point of view of practice, the system of asceticism is constructed with the ultimate perspective of obtaining knowledge of the ultimate aspect of the entirety of the dharmas as taught by the Buddha's teachings. In this sense, the doctrine of the true aspect is the deepest foundation of Zhiyi's doctrine and, as such, it represents an extremely important proportion of his doctrinal system. I think it is important to emphasise this point.