A pristine mind is a purified Subconscious Aka Human Soul (Am) that has no filters to distort the purity of Spirit (I am) flowing through it and into the world to bless all creatures great and small and whose Conscious Mind (I) rests within it as a pure witness.
What Sri Ramana is basically saying is there is no need to employ thought to arrive at self-realization for it is plural thought itself that veils the true Self as Spiritual Consciousness. I know this seems counter intuitive. I know you have spent years using the mind and its thinking processes to come to a truth or to understand the world and your existence. Nether the less it is true. It is the actual process of thinking all these years that has created the veil between Mind-Consciousness and Spiritual-Consciousness. It is taking thought alone that has been the cause of your of separation from your true Self and from living your best life. It is ironic, isn't it, that one must employ a lot of thought to realize it is thinking that is the problem. Life can be such a paradox.
So long as your presence - your I am-ness is caught up in the process of thinking, looking for the truth, it will never find it. The Inner I must be still in order to be found. One must adopt a singular one-pointed focus of Being - a meditative mind needed for the realization of one's true Consciousness as Spirit. Meditation means no-thinking. No thinking means being. Being means meditation. When one's presence Aka Mind-Consciousness is not rising in a continual stream of thought, it is free instead to expand into and as its own Subconscious Awareness that is one with and as the moment. The Subconscious Aka Human Soul or Temple holds the door to the Spiritual realms so to speak. The Spiritual realms are realized if the spiritual aspirant's mind is able to keep still and whole, long enough to expand into and as its own Temporal Awareness rather than rising in its own Consciousness - its own thoughts whereupon its attention is distracted away from seeking the reality of one's Soul, one's Awareness of Being. As one's Consciousness (I) and Awareness of Mind (Am) join together as One instrument or Temple, one's true Self as I AM of Spirit is reflected in and as it, bringing Self-Realization.
One's presence of mind must stay in the Now - quiet and serene. Bear in Mind the Now Aka Present Moment is your physical Soul that is upheld by the true Self within the womb of the One Soul, so when you are present in and as the Moment you as Mind-Consciousness are aligned with your Spiritual Consciousness.
One should, while in and as the Moment, not so much actively listen as passively listen for intuitive guidance. I say this as the mind must be still. If one is actively listening, one activates the mind which is detrimental to Spiritual practice. The mind must practice a deep let go, allowing for a deep relaxation of being that flows with and as the moment, in full acceptance of what is and is not. A state of being that does not entertain any expectation whatsoever while living in complete and utter faith that not only are you being guided intuitively but by the very moment itself through synchronicity and serendipity. It is easy to surrender to the moment when one knows experientially that the moment itself is merely an extension of your very own Being that is ever guiding you to your true purpose. One abides in the Now with and as a choiceless Awareness.
Jesus called the egoic mind Satan. While meditating in the garden he speaks here of being plagued by thought, as we all are, when we begin to discipline the mind in meditation. Peter - one must remember - is a thought - not an actual person for the bible is allegorical - not literal.
Jesus (Spirit) turned and said to Peter (Thought), “Get behind me, Satan! (Mind or thought). You are a stumbling block to me; you do not have in mind the concerns of God, but merely human concerns.”
There is a time for thinking most certainly. There is a time for talking likewise. However, often we talk too much and listen to little. Likewise with thinking. Being is listening to Spirit - being guided from Thy true Self in and of Spirit. Thinking is talking to ourselves as mind. Let us be guided by Thy true Self rather than the Mind that is unconscious of itself Spiritually. Let us partake from the tree of life, not the tree of knowledge. The tree of knowledge would have us create life through thought taken from the mental realm. The tree of life would have us reveal life created by Spirit.
"Don't force anything. Let life be a deep let-go" - Eileen Caddy
~ Love Tracy