The key insight into the spiritual search, the built-in defect in the conceptual logic which has created the body-mind I AM and it's opposite - "world", the crack in the foundation, which has the potential to bring the entire conceptual edifice crashing down - is that the WORD IS NOT THE THING.
No word can describe the actuality. No thought can capture reality. No concept can ever pin down what IS.
The conceptual framework's existence depends on the ignoring or overlooking of this most basic fact - a "chair" cannot describe that thing. As Bob says, can the word "water" quench your thirst? Can the word "fire" burn you?
No - it is the experience that we know, not the concept. And that experience is conceptualized INTO something - into something separately existing, something with independent reality.
And the root assumption which this conceptualization depends on is the subject/object equation. "I" am hearing a "bird".
There is no "I" - "hearing" - a "bird" in direct, actual experience. This is a conceptual creation of immediate experience.
Pure experiencing is the actual fact and function of this moment. Prior to any conceptualization, prior to taking the WORD as the THING, pure experiencing is the only reality. The "I"-subject and the "bird"-object are only conceptual.
Pure hearing is the only reality - and that hearing contains both the hearer and the object heard - one reality.
Beyond that, hearing is still conceptualization which requires a "hearer". Take away that label and what is left?
THIS. Just THIS... no way to describe it, and without describing it there is no way to find any separation.
Separation has to be assumed. The subject/object equation has to be applied. Then the world, body and mind can be.
Once this primary FACT is clearly seen, the house of cards cannot stand for long.