I see it like this that the Buddha saw, knew, that all phenomane are in essence without sign. He knew that the nature of mind is not making signs but he knew this sign-making is the mental factor of sanna.
The signs or meaning mind instinctively, by the force of habit, projects upon phenomena,- signs as nice, attractive, ugly, repulsive, me, mine, my self, not me, not mine, not my self,- whatever signs, that is not really seeing things as they really are, but this is perception, this is the meaningful world of vinnana, the magician. But there is also the signless, empty nature of mind which is different.
Vinnana in the sutta’s is only refering to a moment of awareness. The conscious experience of a sound is the arising of ear-vinnana (many of them), a smell is the arising of smell vinnana , the awareness of an arising emotion, idea etc is a moment of arising mental vinnana.
Like waves on the ocean of the mind.
If you study the brain you will see that vinnana relies on the brain. If you damage part of the visual parts of the brain, no eye vinnana’s arise, you are blind, etc. That vinnana can survive without brain is hard to belief but it is taught like that. I believe it would be absolute impossible if there is no intelligent ground.
Also neurologic science support the idea that things we perceive have no fixed meaning but the brain makes a best guess. This meaning is attributed and can change drastically. The meaning ‘my woman’ can change drastically when certain parts of the brain are damaged. One might suddenly even see that woman that was always yourbeloved spouse, as a fraud who only says she is your woman.
The brain is always constructing meaning. Seen from introspection, we live in a meaningful world. There are signs. The most important meanings that the brain or mind attributes are me, mine, myself.
I believe Buddha discovered the domain of the signless, the domain in which perceptions can arise and cease but have no meaning as me, mine, myself or attractive and ugly, not me, not mine etc.
I believe the Buddha teaches this as the escape.