anjali wrote:I think we all accept the higer-order knowing model: I see an apple; I know that I see an an apple.
The trikaya model takes this three-aspect approach. The three facits/dimensions are, 1. emptiness, 2. clarity (knowing), and 3. radiance or emanation. The knowing knows itself directly; the knowing knows it is emptiness; the knowing knows radiance as itself. Again, none of this involves a knower of any kind. We discuss these three aspects separately, but in fact they are a unity and are indivisible.
Since the beginning Buddhism has the six consciousnesses and eighteen areas of experience, among them the mental consciousness and the area of mental phenomena. Thus seeing an apple is an eye-consciousness where one already has awareness of that appearance, and generating another layer of recognising that one is aware of seeing an apple is mental consciousness. In terms of the aggregates seeing an apple is form, calling it an apple is perception, and knowing about both is consciousness. All of the eighteen areas and five aggregates work together without a problem.
In the internalised trikaya model, as you said, the three are explained separately but they are not actually three different things. There are a number of ways to explain that. The simplest is the statement of the third "kaya" that emptiness and clarity are inseparable; here it is understood that clarity includes all appearances, it is dependent origination. When clarity is meant only as awareness and the nirmanakaya as phenomena, one can add the fourth body to confirm their inseparability. It is also possible to turn to a Huayan explanation where there are 10 bodies, that is, each body includes the other two making nine and all of them together to arrive at ten. So, when you say that knowing knows itself, emptiness and radiance, that is actually the Huayan model. Although logically to say that knowing includes (knows) knowing is nothing but stating that knowing is knowing.