In the Gita we have a process which is not the process of Raja-Yoga. It seeks a shortcut to the common aim and goes straight to the stillness of the mind. After putting away desire and fear, the Yogin sits down and performs upon his thoughts a process of reining in by which they get accustomed to an inward motion. Instead of allowing the mind to flow outward, he compels it to rise and fall within, and if he sees, hears, feels or smells outward objects he pays no attention to them and draws the mind always inward. This process he pursues until the mind ceases to send up thoughts connected with outward things. The result is that fresh thoughts do not accumulate in the chitta at the time of meditation, but only the old ones rise. If the process be further pursued by rejecting these thoughts as they rise in the mind, in other words by dissociating the thinker from the mind, the operator from the machine refusing to sanction the continuance of the machine’s activity, the result is perfect stillness. This can be done if the thinker whose interest is necessary to the mind, refuses to be interested and becomes passive. The mind goes on for a while by its own impetus just as a locomotive does when the steam is shut off, but a time must come when it will slow down and stop altogether. This is the moment towards which the process moves. Na kinchiapi chintayet: the Yogin should not think of anything at all. Blank cessation of mental activity is aimed at leaving only the sakshi, the witness, watching for results. If, at this moment, the Yogin entrusts himself to the guidance of the universal Teacher within himself, Yoga will fulfil itself without any further effort on his part. The passivity will be confirmed, the higher faculties will awake and the cosmic Force passing down from the vijnana through the supermind will take charge of the whole machine and direct its workings as the Infinite Lord of All may choose.
Whichever of the two methods be chosen, the result is the same. The mind is stilled, the higher faculties awakened. This stillness of the mind is not altogether a new idea or peculiar to India. The old Highland poets had the secret. When they wished to compose poetry, they first stilled the mind, became entirely passive and waited for the inspiration to flow into them. This habit of yogic passivity, a relic doubtless of the discipline of the Druids, was the source of those faculties of second sight and other psychic powers which are so much more common in this Celtic race than in the other peoples of Europe. The phenomena of inspiration are directly connected with these higher faculties of which we find rudiments or sporadic traces in the past history of human experience.
Excerpt from the book Essays Divine and Human by Sri Aurobindo