Shinran's letter on Ji'nen ho'ni is regarded as a statement of his mature philosophy, but there are various problems with it, in part due to its context not being clear, other than the fact it was written late in his life. His discussion of jinen honi would indicate that the term was used in Honen's Pure Land community. If we trace back the term, one source of it is the four observations on honi made in a section of the Yugashijiron; the section is also cited in the monumental Zen work "Sugoroku" by the Chinese mater Enju, d. 976. Honi is the elemental law that accounts for why the earth is hard, water is wet, fire is hot, and the wind moves so freely, why all things are impermanent, all dharmas are without self, and nirvana is stillness. In other texts, honi is what determines whether a Nyorai (Tathagata) appears in this world or not. Shinran's description of honi is adapted to the Pure Land view, where the Nyorai's Vow is central and its emergence in the seeker important, but its mention is brief, all too much so.

The letter itself is in more than one collection, but is usually connected with the "Mattosho, the Lamp for the Latter Day" (or possibly meaning the Light at the End of Our Life). The collection was one of the official 39 kana shogyo items selected by the Nishi Hongwanji in the second half of the 18th century. There are a number of classical studies on the collection. The Jinen honi sho was not examined as a separate document until the early part of the 20th century. The number of studies increases in the postwar era, along with the changing demands of the times. D. T. Suzuki includes a translation of it in his 1957 work, "Mysticism: Christian and Buddhist." The well known Buddhist scholar Kajiyama Yuichi also includes it in his edition of a 1987 volume on Shinran. The "Collected Works of Shinran" (CWS) of course includes it in the Mattosho collection. The following is a free translation that attempts to follow the text closely, but problems remain in how to interpret what exactly it is that Shinran intends.

As to ji'nen, [the Truth] arising of itself, when we say "ji-," [that something arises] "of itself" (onozukara), it means it has nothing to do with what the practicer figures [right or wrong]; the word "-nen" means that we are the ones being "bent to its will" (shikarashimu); it has nothing to do with what the practicer figures; the fact that we find the Nyorai's vow dwelling in ourselves is [thus an instance of] ho'ni, the Truth-as-such.

As to ho'ni, it is because we become what we are due to the Nyorai's vow that ho'ni, the Truth-as-such, is imbued with this quality of "bending us to its will" (shikarashimuru). In the Truth-as-such, when we are made over to the Vow, it brings us to the point where the practicer's scheming is virtually eliminated, and we are brought to the state where, its power prevailing, we are [simply] "bent to its will." Everything we do, for the first time in our life, we do without contriving. For this reason, we become those who, without the slightest intention to do so, are made to embody the highest form of Truth (gi-naki wo gi to su).

Ji'nen, [the Truth] arising of itself, is a word that means we have been "bent to its will" from the very beginning. Amida's Vow has, from the very beginning, nothing of the practicer's contriving to it, when it says, "As long as you say Namu Amidabutsu, I will come to welcome you"; it is only when there is no thought of deliberating whether the practicer is good or bad that it is worthy of being called ji'nen; or so I am told.

The whole point of the Vow is the promise to become the Ultimate Buddha. What is known as the Ultimate Buddha is intangible. Because it is intangible it is called ji'nen, [the Truth] arising of itself. When it becomes tangible, [however,] it cannot be said to be the Ultimate Nirvana. It is [only] when it makes itself known to us in its intangible form that we can first call it Amida Buddha, the Buddha of the Infinite; or so I am told.

The whole purpose of Amida Buddha is to inform us of [this] point of ji'nen, [the Truth] arising of itself. [But] after we realize what it is all about, we should not be forever heard talking about ji'nen. For there is no point in doing so. To always go about telling everyone about ji'nen is to make this "highest form of Truth achieved without the slightest intention" again wholly contrived. It is better to leave this mystery of Buddha wisdom where it lies.