Since sattva-guna [the constituent of prakriti which makes for purity, intelligence, etc.] is the nature of mind, and since the mind is pure and undefiled like ether, what is called mind is, in truth, of the nature of knowledge.
Tom: Often the Self is said to be beyond the three gunas (Tamas, Rajas and Sattva). Here Sri Ramana tells us that pure sattva, or pure mind, which is the utterly and totally peaceful mind in its natural state, is actually the Self.
When it stays in that natural [i.e. pure] state, it has not even the name “mind”. It is only the erroneous knowledge which mistakes one for another that is called mind.
Tom: This pure sattva, unlike mixed sattva, is completely devoid of any rajas and tamas, and so is beyond all the gunas.
What was originally the pure sattva mind, of the nature of pure knowledge, forgets its knowledge-nature on account of nescience, gets transformed into the world under the influence of tamo-guna [i.e. the constituent of prakriti which makes for dullness, inertness, etc.], being under the influence of rajo-guna [i.e. the constituent of prakriti which makes for activity, passions, etc.], imagines “I am the body, etc.; the world is real”, it acquires the consequent merit and demerit through attachment, aversion, etc., and, through the residual impressions [vasanas] thereof, attains birth and death.
~ Sri Ramana Maharshi, Vichara Sangraham (Self Enquiry), Question 11