The witness is changeless. However formless witness does not have to know that it is changeless since it is pure consciousness and it is in awareness of itself. And therefore it need not have to know that it is changeless since it is ever pure. The mind or universe being matter, by itself cannot know, since it is matter. The knower of the matter is not the matter but the formless consciousness.
The one who has to realize self is not the matter but the self the witness, which is in the form of consciousness. This knowledge can be got deeper investigation through reason based on the true self, which is consciousness. One has to keep churning again and again until one become firm in his conviction.
Those who say one can become like Brahman, or one with Brahman, or approach Brahman, , realize Brahman--all these are dualistic errors.
When scriptures say: - "That thou art" the meaning is that one must make an effort to know that Atman itself is Brahman or ultimate truth. Atman is in the form of consciousness is there always. One has got it, there is nothing new to be acquired, only have the sharpness to grasp and understand it, when told about it. But there is a difference between understanding and realization. Effort is required for this understanding only, whereas once understood no special effort is needed to remember his understanding: until then he only has an idea of Atman, he only partially understands it. But once he thoroughly grasp what it is and that all these things are Atman or consciousness, he will then constantly find it present everywhere without further effort, because he will perceive ultimate truth by understanding, even in the midst of worldly existence.
For when there is only one thing (consciousness) known, there is nothing to change, nothing to appear or disappear; when one speaks of remembering or forgetting consciousness that implies he believe in the existence of something else, i.e. a second thing, which is to be remembered. That would show he has not known that all is one. But knowing it, there is no second, consequently no intermittent perception of consciousness, but a permanent effortless understanding that it alone is.
The non-duality is the highest truth because it is impossible to contradict it. So long as there are two, one seeing another, man seeing something other than his-self, there is duality and not finality.
No one has seen anyone else impose the limitations and illusions of the world on his mind. Therefore one must conclude that they are self-imposed. Self is infinite but in dream it impose the limitation on itself in the form of an animal which it sees there but which is only created out of consciousness. Similarly in waking it impose other limitations in the form of other objects and persons, everything is really consciousness the true self. Therefore constantly reflect and practice this exercise: viz. "Self is not limited by the body, but the self, which is in the form of consciousness, pervades all the three states therefore it is unlimited." Thus it is erroneous to confine self to the physical entity alone.
