The source is also known as -Spiritual Heart , Primal Energy, Consciousness, Awareness, Plenitude, God - is Unicity, Oneness, and Non-dual reality, Buddha's nature or Chirst.

The “Self” simply means that the non-dual source, which is the formless soul.  The source is also known as -Spiritual  Heart , Primal Energy, Consciousness, Awareness, Plenitude, God - is Unicity, Oneness, and Non-dual reality, Buddha's nature or Christ.

Consciousness is the one behind the many (universe).   If one becomes aware of the soul or consciousness, the innermost self, then the universe in which we exist is mere illusion. Thus our existence as an individual separate from the world is mere illusion created out of single stuff, which consciousness.  

When viewed as waking entity or ego, the waking world seems to be real.   Deeper self-search reveals the fact that, the waking entity is false self within the false experience and the self is neither the waking entity nor the self is the dream entity but the self is the formless soul or consciousness, which witnesses the coming and going of the three states.

Without knowing the nature of the mind or the universe, it is impossible to know the truth. It is of no use of trying to find the truth before one understands the nature of the universe. The world which confronts one is also consciousness itself therefore the world in which man exists is a mere mirage created out of consciousness, which is the innermost self.

If one does not make his induction from facts from the world before him, the world of the five senses, he only draws on his imaginations. Then he says “The ‘Self’   is like this, or like that." but it will be only his imagination within the waking experience, which is mere illusion from ultimate standpoint.

What are these three states? Consciousness never experienced in the plural, only singular of which plural is unknown; that there is only thing and what seems to be plurality is merely diverse aspect this one thing, produced by a deception, which Advaitin sages called it as Maya.   

First seeker must inquire into the nature of the physical body i.e. Matter. Second he must inquire into the nature of the mind to realize, the mind is in the form of the universe and the universe appears as waking or dream and disappears as deep sleep. That is, mind (waking or dream) becomes the soul (consciousness) and soul (consciousness) becomes mind (waking or dream).  Or form (waking or dream)  becomes formless(consciousness)  or formless(consciousness)  becomes a form(waking or dream) .     

The consciousness, the innermost self-pervades in everything and everywhere in all the three states therefore the consciousness is not limited to waking entity and waking world. Thus all the three states   have to be taken into account.  WHO AM ‘I’? An inquiry which exposes the false nature   of the waking entity reveals only half truth.  Therefore one has to indulge in deeper self-search to realize ‘I’ itself is not the self in order to unfold the mystery of the mind or the universe.

Know that which has the  form to be unreal and the formless to be permanent.  One has to look at everything in the world because in everything there is Consciousness because the world is created out of consciousness.  One should not avoid the world   and shut   himself away from the world that confronts him like a yogi and meditator because the world which is as much consciousness, as his body.  It is very much necessary to realize the body and the world are one in essence.