The soul is the formless witness of the three states; and it pervades in everything and everywhere in all the three states and yet transcends them all.

The body which is inert (insentient) and illumined by an external agent be the consciousness, which is present only within the waking or dream?

The soul or consciousness, the innermost self is apart from the three states and permanent, as it endures even after the death of the body and the world   within the waking experience.

Even the subtle body consists of many parts and is unstable. It is also an object of perception, is changeable, limited and non-existent by nature. So how can this be the self, when the body exists only within the waking or dream?

The immutable soul or consciousness is the innermost self and it is  the substratum of the three states. The soul is the formless witness of the three states; and it pervades in everything and everywhere in all the three states  and yet transcends them all.

Thus, the enunciation of the difference between the soul and the body has (indirectly) asserted, indeed, after the manner of the inquiry, analysis and reasoning, the reality of the three states. The birth, life, death and the world are part of the duality (waking or dream). The consciousness, which is the true self and it, is the formless witness of the birth, life, death and the world.

Thus, the view that the body is the true self has been denounced by the enunciation of the difference between the soul and the body. The seeking mind has to grasp the truth, between the three states and the formless witness (soul).