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Duality is real & Non Duality is real. Why not? Have the cake and eat it too! Why should it be this or that?
In oneness, as you have so aptly stated, there is no ‘I’ as in i-dentity. This means, no fragmented thought and no sensory inputs and no memory drawn imagery. Simply pristine unbounded limitless awareness.
As you have also correctly (in my view) stated, the limited mind cannot cognise the unlimited.
Now, even with the knowing that duality is an illusion, while resident therein, it is real for our consciousness. No getting away from this. Equally and perhaps more importantly, the ‘higher’ reality as revealed to our evolving in-form consciousness by limitless oneness awareness (both us!) is valid.
This would mean ... if we are to derive a purpose ... that the one becomes two paving the way for the two to fuse as one in an ecstatic blissful union of love ... love itself displaying its colourations as of our in-form cognitive enableability transitioning from bubbling joy to boundless ineffable bliss to all encompassing compassion and then purity, in ascending order of improved alignment between sheaths of our consciousness.
Or ... accept what is and enjoy the ride ... all analysis being paralysis.
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