The actual experience alone can settle this argument. This is what I found: The ego vanished; the everyday "I" which the world knew and which knew the world, was no longer there. But a new and diviner individuality appeared in its place, a consciousness which could say "I AM" and which I recognized to have been my real self all along. It was not lost, merged, or dissolved: it was fully and vividly conscious that it was a point in universal Mind and so not apart from that Mind itself. Only the lower self, the false self, was gone but that was a loss for which to be immeasurably grateful.
-- Notebooks Category 28: The Alone > Chapter 2: Our Relation To the Absolute > # 142
-- Perspectives > Chapter 28: The Alone > # 31