Scholars have found that when texts are copied by a series of scribes, the texts drift due to an accumulation of mistakes by scribes. Usually it is said that the texts become corrupt, but I'm not fond of that word in this context. In any case, this produces different texts from different lines of scribes.
Therefore, it is no surprise that a dream last night alerted me to a glitch in the Buddhist literature which seems to indicate one or more mistakes by scribes.
Ancient Indian logic has four categories, not two as in the West. These are true, false, both true and false, and neither true nor false.
Now remembering from what I read several decades ago, the Buddha was asked if he would still exist after final Nirvana. He said "no". Then he was asked if he would cease to exist after final Nirvana, and he again said "no". Then he was asked if he would both exist and not exist, and said no, and then was asked if he would neither exist nor not exist, and he said "no" still again.
In the literature, this is taken to mean that neither the philosophy of Eternalism nor Nihilism is correct.
However, notice that the Buddha was asked about a neither existing nor not existing, and said "no". But neither X nor not-X is what the neither Eternalism nor Nihilism pair is. So there is a glitch in the Buddhist literature there.
Now let us look at the fourth and highest immaterial state described in the Visuddhimagga. That is a state of neither perception nor nonperception, so it is another neither X nor not-X and parallel to the one described above. As I understand it, the state of neither perception nor nonperception is below the state of enlightenment.
"Form is Emptiness and Emptiness is Form" is both X and not X, so is partly similar and partly different from the two above.
Now comparisons often help, so for a comparison, let us look at Kant.
Kant held that only something which transcends space and shapes can perceive space and shapes. To sort of understand this, let us look at an example. The example should not be confused with the limits of small changes in calculus, for near the limits, the changes become INVISIBLE to the eye. So for visible shapes, one cannot make a true circle out of small squares. Therefore, a group of small squares could not be a consciousness perceiving a circle.
All shapes are on one level. It is necessary to move up to a transcendent level for them to be perceived. Kant calls that transcendent which can perceive phenomena the "noumenon".
Now back to the Buddhist literature. The neither X nor not-X defines a transcendent. Thus, since neither perception nor nonperception, and neither Eternalism nor Nihilism are themselves transcendents, and Nirvana is a level above them, then Nirvana seems to be something somewhat like a transcendent of transcendents. That kind of complexity could be confusing to a scribe.
Now on a related matter, the information processing in the brain involves physical movements of ions and neurotransmitter molecules in various changing shapes in space. We can compress this idea to "changing shapes of nerve impulse patterns" in order to make is easier to talk about. The brain's function is limited to those physical changes in the shapes of nerve impulse patterns. Therefore, the brain itself cannot perceive space and shapes, because only something transcendent can perceive space and shapes. The brain can only calculate. Since the brain itself cannot transcend, the brain cannot be conscious.
Consciousness, which does and must transcend, decodes the nerve impulse patterns and overlays them with consciously perceived subjective space and shapes, and so forth.
That is also where evidence for reincarnation comes in. It takes great skills, which in this case operate in the "unconscious" part of consciousness, to decode nerve impulse patterns of up to hundreds of thousands of nerve impulses. For comparison, consider how difficult it is to find the hidden figure in a page of dots on a conscious level, which even of the best quality, contains many fewer dots than the nerve impulses in a nerve impulse pattern. Of course, dots on paper are different from nerve impulses, and we don't have a long history of working with dots on paper. In any case, the skill to decode nerve impulse patterns is so great that it could only have been learned over many lifetimes. That is thus evidence for reincarnation.
There are a vast number of details still to be discovered about what a mind is and how it gets from one brain to another.
If one only wants to become enlightened, it is said that one doesn't have to learn or discover all that knowledge. One can become enlightened just by meditating properly.
However, if one wants to save other beings, it is important to discover everything until one has a full knowledge of consciousness.