"only dharma practice leads to the manifestation of these realms", referring, for the purposes of this post, to the Buddha-realm/dhātu/element/quality (界), which is unrealized and unmanifest?
So I've been thinking of the above, and I think that the above has to be viewed in light of karma, causes, and conditions, but only controversially so.
For instance, it is technically
possible to attain complete saṁbodhi after one exposure to the Buddhadharma, depending on (past? present?) karma, causes and conditions, etc. This is unlikely to the point of "practical impossibility" (it would be interesting to know if this was "still" believed to be the case in a Nichiren context, namely, in the context of mappō
). I think that this principle still stand in Dharma Degeneration, though, because I think
(but do not know, as I am not an expert in the subject matter) that, in the context of Nichiren Buddhism, one can still
become enlightened after just as much as one hearing of the saddharma
, for instance of the Lotus Sutra, or via participation in Daimoku. It is still unlikely to the point of near-impossibility, but possible, yes?
That being said, the above discourse reminds me of a conflict in Tendai Buddhism, between two subsects, one of which is labelled today as heterodox and the other orthodox, in which one "heterodox" (heretical?) subsect posited a Buddha(hood) predicated on causes and conditions. I believe the mainstream Tendai view that won out was that Buddha(hood)/Awakening was not predicated on causes and conditions, but I am not familiar enough on the matter to know for sure.
If I may elaborate, the criticized hongaku, the "a-hongaku", if one will, which seems to be criticized by Nichiren and Buddhists outside of his dispensation alike, wherein all are anuttarasamyaksambuddhas fully realized without the need for practice, seems to be a product of viewing the first truth to the exclusion of the other two. It is viewing things in light of emptiness, which isn't wrong, but isn't viewing things on terms of the delusion and defilements that block the understanding of fundamental emptiness.
From a certain perspective, the perspective of some Tathagatagarbha sutras, we are all of us Buddhas fully realized, yet paradoxically covered in defilements, which don't exist themselves and yet somehow still obscure Buddha(hood). However there is also the appearance of myriad dharmas, the appearance of seperateness and dinstinctness, the "appearance" or "likeness" of inherent reality/existence. There is also a non-duality or "not-two-ness" between the two.
The hongaku which sees all as Buddha without defilement, I think at least, is only operating from 1 of 3 truths, namely the first only
and to the exclusion
of the other truths, and is therefore insufficient. The hongaku which is Buddha-nature is not subject to this criticism it seems to me.
Note: I got here but soon go
Similarly, from the Mahayanamahaparinirvanasutra, we have an identification of Buddhadhaatu and Tathaagatagarbha as aatman. I think this may be, and this is just IMO, but a vision of Buddhahood from the perspective of specifically the second truth, the myriad dharmas.
From the perspective of the deluded being, from the perspective of the myriad dharmas, from the perspective of the second truth, awash in myriad shifting dharmas, in the ocean of impermanence, Buddhahood, Buddha-nature, and Nirvana, "appear" or "seem" stable, eternal, unchanging, unperishing, like God, Heaven, Divinity, and Atman. But this is an "appearance" or "similarity", or "certain perception", not a reality or necessarily even a "true perception". This perception is a product of the perspective of the myriad dharmas, which, although themselves not "untrue", can still produce conventionally "false" understandings when viewed as a truth exclusive to the other 2 truths. That is why we have such language also in the Mahaayaana canon. Perhaps that is just my own delusion though. But I see it as a reconciliation of this language with what I understand of the Tiantai framework.
In short, a nirvana in light of Madhyamaka, in light of Tiantai, in light of Nichiren(?), can probably be called "original" "root" or "primordial", but that would probably also imply a primordial samsara to accompany nirvana in non-duality.
That is just my own thoughts though.