When it comes down to knowing i feel we can in practice distinguish different situations.
Mn28 says: Though the eye is intact internally and exterior sights come into range, so long as there’s no corresponding engagement, there’s no manifestation of the corresponding type of consciousness.
What does this engagement mean? I believe that it means that the mind has a specific interest for something. This is personal but also interpersonal.
Example: when you walk on the street you see many things. They are in the range of the eye. But they do not catch your eye or mind. You see them but not in an engaged way.
But now on your walk you suddenly see something and that really catches your eye because mind is engaged, for example, via lobha or dosa, like or dislike. A visual has arousen a certain interest of mind. This i consider as engagement mentioned in MN28
You becomes focussed on something and very aware of that something. Now eye vinnana has really established itself. Before engagement there were also visuals, but eye vinnana’s did not really establish.
You can recognise this right?
Isn’t there a huge difference in experiece, in the mind, between just seeing and eye-catching engaged moments?
Probably in the time of the Buddha it was self-evident that vinnana is a moment that the knowing has becomes fixed upon something. So, vinnana it is not merely knowing, it is also a moment of rigidness. It is burdensome and very different when there are no eye-ear mind catching moments, right?
So, it is normal that vinnana nirodha is seen as bliss because then the burden of this unwillingly fixation of the mind on sense-objects, this being caught, does not happen and that is peaceful.
Vinnana may be said to know sour, red, cold etc. because it is a fixated knowing moment in which there is strong awareness of something specific, a sour taste for example. BUT that does not mean that there is no knowing that is not-fixated, right? Not all knowing has this character of vinnana.
When the sutta’s say that vinnana knows… i do not believe that it says that apart from vinnana there is no knowing. What it means is: vinnana knows specific things via fixation, a sour taste, a pleasant smell etc. But there is also knowing that is not fixated. A knowing before engagement happens. A Knowing before the eye, ear…mind is caught.
So, like i understand MN28, vinnana is a fixated knowing moment. An eye-, ear,- mind caught moment.
Engagement is its condition. Something very specific has aroused interest of the mind. Due to that specific and engaged attention vinnana’s establish. In a sense the mind coarsens now.
If this engagement does not happen, there is also knowing but not fixated. But the knowing of vinnana always is. The fixation at the same time is the burden of vinnana.
Maybe this non-fixated knowing is refered to as anidassana vinnana. I feel the word is not important.
I think we can from practice see there is a knowing and that is not fixated.