THE THREE THOUSAND REALMS IN ONE MIND. This doctrine forms the essence of the Makashikan (Mo-ho-chih-kuan), a twenty-section work in which T'ien-t'ai Chih-i of China systematized various teachings included in the Lotus Sutra. This was his new interpretation of the Lotus Sutra. Nichiren regarded Chih-i's doctrine of the Three Thousand Realms in One Mind as the essence of the Buddha's teachings.

In the second section his work Kaimoku-sho (Essay on the Eye-opener), Nichiren extolled this doctrine in the following words: "Unless people attain buddhahood through the teaching of the Three Thousand Realms in One Mind, their attaining nirvana and becoming buddhas will be little more than a mere name." In the first section of the same work, he also praised the doctrine as follows: "The very doctrine of the Three Thousand Realms in One Mind of the Tendai sect appears to be the way to lead people to buddhahood." Nichiren specifically extolled this doctrine a total of eighteen times in his works.

What is the teaching of the Three Thousand Realms in One Mind? As has been mentioned, our minds revolve ceaselessly in the six worlds of hell (anger), hungry spirits (covetousness), animals (ignorance), demons (dispute), human beings (normality), and heaven (joy). Thus our sufferings continue endlessly.

However, even an ordinary person sometimes rises to the level of the four realms of the saints. One conceives the desire to study the right way to live (sravaka), realizing it intuitively from one's experiences (pratyekabuddha), and wishing to live for the benefit of people and society (bodhisattva). But one will seldom if ever reach such a mental state of absolute compassion that one completely forgets oneself. It would be a great thing if one could maintain such a mental state constantly. But soon one's mind returns to that of an ordinary person without one having made any lasting improvement.

THE TEN REALMS OF BEING FOUND IN ONE ANOTHER. Everyone's mind possesses the ten realms, the six of the ordinary person and the four of the saint. These ten realms exist in the minds of heavenly beings, as well. The ten realms exist in the mind of each person in each of the ten realms. This is jikkai-gogu, or "the ten realms of being found in one another."

The seed of the buddha-nature is also possessed by those who are in the worlds of hell and demons, although it is very undeveloped. The doctrine of the Three Thousand Realms in One Mind teaches that even those who are in such a state of mind have the possibility of attaining buddhahood and that the chance of salvation can be found anywhere. In other words, this doctrine teaches plainly that the Buddha's compassion extends to all living beings. On the other hand, even when one thinks one has realized and become free of the bonds of illusion and suffering, by studying the doctrine one will become able to reflect on one's remaining seeds of illusion and will come to wish to devote oneself still more to one's practice.

Each of the ten realms exists in the mind of everyone in each of the ten worlds. Ten multiplied by ten equals one hundred. One hundred minds appear in the ten ways according to the doctrine of the Ten Suchnesses (ju-nyoze).

THE TEN SUCHNESSES. This doctrine consists of ten words prefaced by "such a" or "such an": "such a form" (nyoze so), "such a nature" (nyoze sho), "such an embodiment" (nyoze tai), "such a potency" (nyoze riki), "such a function" (nyoze sa), "such a cause" (nyoze in), "such a condition" (nyoze en), "such an effect" (nyoze ka), "such a recompense" (nyoze ho), and "such a complete fundamental whole" (nyoze hommatsu kukyo-to). This doctrine reveals the deepest reality of the existence of all things in the universe, which is called the principle of the Reality of All Existence (shoho jisso). Modern science has analyzed physical substances to the extent of subatomic particles. But the principle of the Reality of All Existence is much more profound than such an analysis, extending even to the mental world. The Chinese character read nyo means shinnyo, meaning "that which is constant and unchanging." Nyoze means "such" or "thus," and also "invariably," "without fail," or "without error."

The existence of all things invariably has form. This is called "such a form." That which has a form invariably has a nature. This is called "such a nature." That which has a nature invariably has an embodiment. This is called "such an embodiment." That which has an embodiment invariably has potency (energy). This is called "such a potency." When it has potency, it invariably produces various outwardly directed functions. This is called "such a function."

Innumerable embodied substances exist in the universe. For this reason, their outward-directed functions are interrelated with all things. Nothing in the universe is an isolated existence having no relation to other things. All things have complicated connections with one another. They are interdependent and through their interaction cause various phenomena. A cause that produces such phenomena is called "such a cause."

Even when there exists a cause, it does not produce its effect until it comes into contact with some occasion or condition. For instance, there is always vapor in the air as the cause of frost or dew. But if it has no condition that brings it into contact with the ground or the leaves of a plant, it does not become frost or dew. Such an occasion or condition is called "such a condition." When a cause meets with a condition, a phenomenon (effect) is produced. This is called "such an effect."

An effect not only produces a phenomenon but also invariably leaves some trace or residue. For example, the effect of frost forming will give a pleasant feeling to one person who enjoys the patterns it makes on the windowpanes, while the same effect will give an unpleasant feeling to someone else whose crops have been damaged by it. The function of an effect leaving a trace or residue is called "such a recompense."

It will be helpful to explain cause, condition, effect, and recompense in more detail. Suppose a man has offered his seat in the train to an old woman. In his mind he possesses, as a cause, the potential of wishing to be kind to others. When such a cause comes into contact with a condition, in this case his seeing an old woman staggering while trying to stand in the train, it produces the effect of his offering his seat to her. Afterward he feels refreshed, thinking, "I have done something good." This is recompense. This recompense comes from one's mind as well as from outside. The former comes first to him, and it is the most important recompense.

The nine suchnesses mentioned above occur incessantly in society and in the universe as a whole. They are interconnected in a complex manner, so that in most cases, a person cannot discern what is a cause and what is an effect. But these suchnesses never fail to operate according to the law of the universal truth, and no one, no thing, and no function can depart from this law. Everything functions according to the Law of the Ten Suchnesses, from form to recompense, namely, from beginning to end. This is the meaning of "such a complete fundamental whole." The fact that all things, including human beings, and their relations with one another are formed by this law is called the Reality of All Existence.

The hundred worlds mentioned earlier operate in the ten ways shown in the law of the Ten Suchnesses. Ten multiplied by one hundred is one thousand; therefore one hundred minds have one thousand functions.