For a meditator, Vivek, the power to discriminate between the Unchanging and the ever-changing, is an absolute necessity. Without it s/he is eternally caught in the wheel of the mind that can only discriminate within the duality of its limited spectrum. The mind will know the difference between good and bad, black and white, right or wrong and especially between what it likes and doesn't like. In other words, the mind has the ability to discriminate within the dimension of the ever-changing waking state, but it can't go beyond.
In everyday life, our attention is focused exclusively on the changing world of things and forms. We are engaged with our thoughts, desires, preferences, projects and hopes for specific outcomes. The human mind is literally hypnotised by the constant movement in this ever-changing field. The awareness of the Unchanging Space of Freedom at the back of it is lost when the attention is caught up in the form level experience.
In order to reorient our attention, a different kind of knowledge is needed. The knowledge we are talking about here is not just information processed through the intellect. It is knowledge that invites us to explore the existence of a part of us that is invisible and unchanging. For this experience to unfold, we need to close our eyes. When we meditate, we withdraw our attention from the movement of thoughts and we direct it to breath or mantra. By withdrawing attention from our thoughts, we also withdraw their energy to move and pull us in. Eventually the movement of the mind will subside and we remain with That which is always present - the unchanging space of the Self that is our True Nature.
When we experience the space of our True Nature as our very own Self, we are left with sense of Pure Freedom that is hard to put in words. Since the experience is not happening within the realm of the mind, and since words are the mind's tools, it is not surprising that they can't really express the vastness of the experience of Freedom. And yet the experience is known with great clarity. That is when we realise that Freedom is not experienced by the ego
/mind/intellect, but by Freedom or the Self itself. More importantly, we realise that the Self experiencing itSelf is not separate from me. The individual self and the Unchanging Self are one and the same Space of Self. One is infinite and unchanging, the other is also infinite, but it APPEARS to be changing and moving - yet it is the same fundamental Space of Self.
Recognising this fact is the subtlest form of Vivek. The unfoldment of the power of Vivek in our lives is a result of our Meditation practice. When we become firm in our knowledge of the Self as our True Nature through a regular practice, we are no longer fooled by the antics of the mind. This is how instant recognition of the Unchanging as Me becomes our way of life.