The unknowable can be known. Self is neither unknowable nor remains unknown at any moment. A man of truth can guide the seeker to something which always remains unknown. If a man of truth can guide, it means that he knows about it. This transcendental state is quite easy or may be well-nigh impossible, it depends entirely on seekers receptiveness and intense urge to know the truth of his true existence. It is very difficult for the people whose has materialistic outlook and stuck with their own idea of truth. It cannot be grasped if it always remains unknown.
Whatever one experiences becomes known by the formless knower. Seeker carefully has to analyze the underlying substance which, though abstract and apart from known, yet illumines them all the same. Know it to be the truth.
What is not self-luminous can only fall within the orbit of knower and cannot be knower itself. The knower is that by which objects are known; it cannot be what it is if it becomes the object of knowledge.
What is known must always be different from knower itself, or else it could not be made known by it. Intelligence in the abstract cannot admit of parts, which is the characteristic of known. Therefore known comes into existence. The seeker has to carefully observe the knower after eliminating all the known from it.
Just as a mirror takes on the hues of the images, so also the formless knower assumes the waking/dream objects by virtue of its holding them within itself.
Formless knower can thus be made manifest by eliminating from it all that can be known. It cannot be known as such and such, for it is the formless substance witness of the known.
This, being the Self of the seeker, is not cognizable. The seeker has to investigate his true Self in the aforesaid manner. There is no other agent to neither know the Self nor light by which to know it.
Self the formless knower is not the body, but the knower of the waking or dream which contains the body and the world, which are all transient. Waking or dream is known, so how can knower be the known?
Knower surpasses the known, at the time of ability to acquire knowledge of the known.
The question arises only in ignorance if seekers judgement is based on the waking entity or ego. From the ultimate standpoint the universe including our body is an illusion. From the physical point of view the universe including us is reality.
It takes umpteen times, to understand this because we are conditioned to view, judge and reason on the physical base thus our reasoning is based on the ego. Therefore, there is a need to rectify the reasoning base from form to formless base in order to know what truth is and what illusion is.
Without knowing what reality is it is impossible to accept anything as illusion. Therefore it is necessary to first decide whether the self is the form or self is formless. If self is the form then the universe will prevail as reality. If the self is formless then the universe has to be accepted as illusion. It takes a very long time to rectify the reasoning base from to formless thus it takes time to understand and assimilate and realize the self-knowledge or Bramha Gnana or Atma Gnana.