I have pondered this for some time, I hope my response makes sense and is appropriate here.
Thanissaro distinguishes two mental states, as present on the commentary on AN 1.49-52 featuring the luminous mind. He refers to DN11 and MN49 in relation to Viññanam anidassanam which he sees as fundamental different, outside the “all”, which is defined in SN 35.23 (Sabba Sutta, access to insight, might deviate from sutta central numbers).
If I address DN11 first, I do not come to the same conclusion.
The Buddha reframes the original question, then answers on where water/earth/fire/wind have no footing, being one of the formless meditative states.
It then expands to long & short. coarse & fine, fair & foul and name & form coming to an end in that state.
This is linked to the cessation of consciousness and with that separate.
The same applies to MN49, where the the “all” ends in “conscious where nothing appears” which is again one of the formless states. The Buddha takes the opportunity to teach about the danger of (continued) existence, which will come to an end.
To this point we agree.
This however brings me to @sujato saying:
Once again his explanation is truthy. Yes, sensory consciousness stops. But because the Buddha defined the senses very broadly as the “all”, this includes any kind of consciousness whatsoever (yaṁ kiñci viññāṇaṁ )
As well as:
Thanissaro wants us to think there is a “direct experience”, i.e. a form of mind or consciousness, that persists when the six senses have ceased.
I think this requires some elaboration before I can agree.
MN121 gives insight in the processes leading up to signless immersion.
The neither/nor state is clarified as: There is only this that is not emptiness, namely that associated with the six sense fields dependent on this body and conditioned by life. This is, as far as I recall, also the notion of an arahant after liberation. Yet this liberation comes from cessation, and the realisation afterwards: ‘Even this signless immersion of the heart is produced by choices and intentions.’ They understand: ‘But whatever is produced by choices and intentions is impermanent and liable to cessation.’
The question remains: is signless immersion (cessation) equal to a form of consciousness or not?
If we look at An10.7, the answer appears to be yes.
I’m not entirely happy with the translation though. It’s too elaborate. The essence is that the process of becoming and cessation turn into one (just like the flame) and in between the freedom related to “not becoming nor cessation” is experienced.
From SN41.6 we know even more, being that “the faculties” are very clear. That’s certainly not an unconscious mental state.
I consider that Thanissaro places this experience “outside” the six senses.
The six senses require a point of focus, which is not present in signless immersion.
Yet, as I’ve already pointed out above, that would not imply that this is a lasting state (experience) for an arahant.
Even more, the notion that the state is willed, produced by choices and intentions and thus liable to cessation" should give rise to disenchantment (disillusionment) and dispassion, which are key to knowledge and vision of freedom.
I know that Thanissaro is not consistent in his notion about the consciousness of an arahant after death. And that ven. Maha Bua pressed even further in his teachings about the citta (specially when writing about ven. Mun).
I however like to keep in mind that they both, with their limitations, attempt(ed) to describe the experience of cessation and the experience of an arahant. Where these limitations might be our our side, the listener, as well.
This brings me to the last item I like to address:
Is there really a meaningful difference between saying “all things are not self” and “there is no self”? It’s tenuous at best.
To me there is a huge difference.
Saṅkhārā carry both dukkhā and aniccā, but the experience described above contains neither. It’s not something the mind fabricated (made up).
However, with it being dhammā it still requires an effort to achieve/maintain. And it’s this effort which creates an affliction (I want my mind to be like that all the time).
It’s by taking the experience as it was, by recollection and anticipation, and making an effort to achieve just that, that dhammā is turned in saṅkhārā, something it’s not.
The notion “there is no self” is a similar saṅkhārā when not approached from precisely the right angle.
It’s interesting how the Buddha challenged various people into pointing him out by the aggregates, and they had to come to the conclusion they can’t. Resulting in notions such as … when the Buddha dies, the aggregates come to an end. Or … there is stress, it’s origin, it’s cessation, and the path to this cessation of stress.
There is no answer to the self/no self question, just as there is no answer to the question “when a flame goes out, in which direction did it go?”. The question itself was wrong, and on self/no-self the various degrees of answers show that the Buddha assessed knowledge based on the question and responded to that by silence (you lack fundamental understanding), reframing the question (this is more appropriate to ponder) and answering from various perspectives (this understanding leads to that, such understanding to such answer).
From a practical perspective: when I slam my finger with a hammer, there is pain. When I add mental notions of “I am hurting” to it, I add additional layers of stress on top.
The same goes for the notion “I am”, since that can lead to pondering such as “what will happen when I am not…?” which can turn rather stressful. Yet the same notion “I am not” can lead to similar stress.
I get the impression that the Buddha was very wary about “ultimate truths”, to the point that even his main teaching contains four components: stress, it’s origin, it’s cessation and the path leading to cessation of stress. When you see the end, how can you say there is stress? If you see the beginning, how can you say there is no stress?
Thank you for your elaboration on Thanissaro’s book.
And I hope my response adds some clarity instead of confusion.