The original quote was:
"The essential point is this: The luminous and knowing aspect of a given state of consciousness must come from a prior moment of that consciousness. It follows, therefore, that it must also beginningless. For were a beginning to the continuum of the luminous and knowing aspect of consciousness posited, we would then have to concede that consciousness arose from a cause that is not commensurate with it, which is untenable. "
And I have gone back and reread it. Suddenly something jumped out at me. I think I made an error in understanding what the subject matter was.
He did not say that consciousness arises from a previous moment, although that may be true. He said the luminous and knowing aspect
arises from a prior moment of consciousness, and that is the subject of the paragraph, not consciousness itself.
This could change the discussion completely.
Why? There is no change whether you call the phenomenon "consciousness" or "subtlest consciousness" or "luminous and knowing aspect". Just replace the variable with "phenomenon X" then you have the generic arguement which has the same fault.
Actually the only "news" is the "aspect" but then again you arrive at "aspect of what?" which is no different form the "quality" RNM has introduced ... it is an endless regression. This "aspect" stands for "consciousness" so you might as well leave it at simply "consciousness".
There has been some wrestling here about the mention of commensurate causes. I don't know much about the idea, but I believe that it basically means a virtuous action will not give rise to bad karma, and an apple will not give rise to a rhinoceros. There is a limit to what may arise from a given cause, and in some sense the effects carry forward some of the characteristics of their causes.
Matter can give rise to light. Matter can give rise to energy. The argument above would claim "Only the cause light is commensurate with light" and "Only the cause energy is commensurate with energy". But this is obviously not correct. Now you may say: Well actually "matter" is "energy", so to say that "Only the cause enegry is commensurate with energy" is correct. But this then begs the question: What is consciousness that renders it not commensurate with matter/energy/light being its cause? The answer is our "not knowing". We do not know what may be "in" matter or "an aspect of" matter that could be a cause commensurate with consciousness.
There is a phase transition from matter1 being energy to (matter2 being energy + energy released).
Why can't there be such a phase transition from matter1 to (matter2 + "consciousness")? I tell you why this possibility
is obstinately ignored: Because the observer is the observed.
Now I feel like I am getting somewhere
Why? Because your sole intention is to support the argument. That is how it always works: The intention determines the outcome from the beginning
Logic has its applicability in Buddhism where there is intention to validate the teaching of the Buddha. The Buddha never asserted a permanent aggregate. Never ever did he do this.
Logic has no applicability where the intention is to replace not-knowing with speculation.