Dualist sages could not distinguish between ‘I’ and ‘formless witness.’

 It is the soul, the innermost self that has to Wake up to realize it is without the body and without the world.  The self is not you (I or I AM).   You are limited to the waking experience, which is mere illusion whereas the consciousness pervades all the three states. 

 Holding the waking entity (you or I AM) as self is erroneous.  The self is not waking entity and waking experience is mere illusion.    It means you are (I AM) part of the illusion.  The one which witnesses the illusion (mind or universe) is   not the waking entity (you) but it is the soul . Soul  or consciousness is is ever apart and ever formless.

People think ‘I’ or ‘I AM as self only their body is not self. Only when the ‘I’ is there than only the body, ego and the world is there. If ‘I’ disappears than the body, ego and the world disappear.  Without the ‘I’ there is neither body, nor ego and nor world.  The ‘I’ is present when the mind is present. Mind is present only when the universe is present. Universe is present only when the waking is present. Waking is present only when there is ignorance. 

Thus ‘I’ is cause of the ignorance. Getting rid of the ignorance is very much necessary in pursuit of truth.   

Non-dualistic truth is supreme truth; all dualistic systems hold false self [ego] as real self and false experience [universe or waking] as reality.  Non- dualistic wisdom is culmination of all systems including theistic non-duality.   The true non-dualist will not quarrel and argue with any theoretical philosophy because he is fully aware of the fact that, this orthodox theistic non-dualistic scholars or pundits like Dualist sages could not distinguish between ‘I’ and ‘formless witness.’ The 'I' was the witness. Their highest was the Jiva. One is so much attached to the 'I' that he do not want to think that 'I' does not exist. Again one is unable to detach the ‘I’ from the Real witness.