[In the parable of the good physician], a father—a physician—cannot convince his children, whose minds have been warped by poison, to take an antidote. So he leaves some medicine for them, disappears, and then sends someone to tell his children that he is dead. Hearing this, a deep longing for the father arises in the hearts of the children, bringing them to take the medicine. As a result they are cured and their eyes opened. Hearing that they had recovered, the father reappears. The children in the parable correspond to lost and wandering beings, and the father corresponds to the Everlasting Original Buddha. The father’s disappearance is comparable to that of the Everlasting Original Buddha, who has a kind of temporary extinction in order to correct the people’s hearts and minds and open their eyes.

The parables of the three carriages in chapter 3, and of the lost son in chapter 4, the simile of the rain and plants in chapter 5, the parables of the magic city in chapter 7, the jewel in the hem in chapter 8, the jewel in the topknot in chapter 14, and this parable of the physician’s sons in chapter 16 are called the seven parables of the Lotus Sutra and have been highly valued from ancient times.

[The] Lotus Sutra maintains that the actual and concrete Shakyamuni is in reality a version of the eternal. That is, the eternity of Shakyamuni Buddha that is emphasized is not a truth-body behind him, but the concrete and actual Shakyamuni himself. In other words, the concrete, historical, actual Shakyamuni is the living embodiment of eternal life. His death or extinction, on the other hand, was just an expression of a convenient, temporary device.

The Buddha appears to be invisible in the teaching of chapter 16, in order to open the eyes of those who have narrow ways of thinking about being and nonbeing, and such. This is his so-called extinction. Those who have their eyes open know that the concrete and actual Shakyamuni Buddha exists eternally. This matter is summarized in lines of beautiful poetry in the verses at the end of the chapter. Kumarajiva’s translation of them begins with a phrase that has been lovingly recited from ancient times: “Since I became a buddha . . .”

[T]he actual Shakyamuni is the living form of eternal life and the manifestation of a transhistorical Shakyamuni in history. Accordingly, even if that manifestation disappears, Shakyamuni does not. He exists eternally, beyond ordinary ways of viewing or thinking about being and nonbeing. Those who go beyond such ways of viewing or thinking can grasp this. This is the second meaning of the theory of everlasting Shakyamuni Buddha. In brief, the transhistorical Shakyamuni Buddha and the historical Shakyamuni Buddha are united. …

the Stupa indicates that the worlds of the ten directions are unified into one buddha-land. This, too, is intended to reveal that Shakyamuni Buddha is a unifying Buddha.

Chapter 16 finally completely reveals that Shakyamuni is really the Everlasting Original Buddha. Shakyamuni himself emphasizes this, saying that the everlasting Shakyamuni goes beyond the ways of thinking about and viewing things used by ordinary people, who cling to being and nonbeing. The sutra says:

“The Tathagata has insight into the threefold world as it really is. For him there is no birth or death, neither retreat from nor emergence into the world, no transmigration or extinction, neither being nor nonbeing, neither existence nor nonexistence, neither sameness nor difference, and neither deception nor non-deception. He does not see the threefold world through the eyes of an ordinary person.”

Thus, those who are deluded by inverted or perverse ways of thinking cannot see Shakyamuni:

Perverse living beings fail to see me
Even though I am close.

It is before those who are upright and gentle, and have put attachment to desire behind them, that Shakyamuni appears:

And when the living have become faithful,
Honest and upright and gentle,
Then, together with the assembly of monks
I appear on Holy Eagle Peak.

In other words, those who are free from attachment to such things as being and nonbeing are able to see the Buddha.

[C]hapter 16 is traditionally understood as showing that Shakyamuni is the Everlasting Original Buddha, and from that point of view, is regarded as the core of the second half of the Lotus Sutra. Since it does maintain the eternal life of Shakyamuni, such an interpretation certainly seems reasonable, but it is important to notice how that eternal life is taught.

The inception of the revelation of the everlasting life of Shakyamuni Buddha is in chapter 15, where a question is raised about the countless bodhisattvas who emerged from the earth and were said to have been taught from the remote past by Shakyamuni. Here at its inception, the teaching of the eternity of Shakyamuni Buddha is already related to bodhisattvas.

Thus, since I became Buddha a very long time has passed, a lifetime of innumerable countless eons of constantly living here and never entering extinction. Good sons, from the beginning I have practiced the bodhisattva way, and that life is not yet finished…

In short, unlimited, endless bodhisattva practice is used to demonstrate the eternal life of the Buddha.

In Christianity, where the absolute God of monotheism was affirmed, the relation between reason and faith became a big issue, and arguments developed around three positions—having faith in order to know, knowing in order to have faith, and having faith although it is irrational. In Buddhism, such serious arguments never arose, because the conception of God found in monotheism does not exist in Buddhism. In other words, the Everlasting Buddha of chapter 16 of the Lotus Sutra is essentially different from the One God, the supreme deity commonly seen in India, and from the monotheistic deity of Christianity and other religions.