“He who knows the receptacle (Ayatana) verily becomes the receptacle of his people. Mind is verily the receptacle (of all our knowledge).” (Chhandogya Upanishad, V-i-5).
The Mind–a Mystery
The vast majority of men know not the existence of the mind and its operations. Even the so-called educated persons know very little of the mind subjectively or of its nature and operations. They have only heard of a mind.
Western psychologists know something.
Western doctors know only a fragment of mind. The afferent nerves bring the sensations from the periphery or extremities of the spinal cord. The sensations then pass to the medulla oblongata at the back of the head, where the fibres decussate. From there, they pass on to the superior frontal gyrus or superior frontal convolution of the brain in the forehead, the supposed seat of the intellect or mind. The mind feels the sensations and sends motor impulses through the afferent nerves to the extremities-hands, legs, etc. It is a brain-function only for them. Mind, according to them, is only an excretion of the brain, like bile from liver. The doctors are still groping in utter darkness. Their minds need drastic flushing for the entry of Hindu philosophical ideas.
It is only the Yogins and those who practise meditation and introspection that know the existence of the mind, its nature, ways and subtle workings. They know also the various methods of subduing the mind.
Mind is one of the Ashta-Prakritis. “Earth, water, fire, air, ether, mind, reason and egoism-these constitute the eightfold division of My Nature” (Gita, VII-4).
Mind is nothing but Atma-Sakti. It is brain that wants rest (sleep), but not the mind. A Yogi who has controlled the mind never sleeps. He gets pure rest from meditation itself.
(pgs. 3-4, Mind —Its mysteries and Control)