The Gita recognizes that the kind of radical change in standpoint and awareness that it asks the seeker to attain is not something that generally comes easily or without process and effort. Arjuna expresses the concern that any of us would feel, when he points out the difficulty of achievement and his concern about the fate of someone who tries to accomplish the yoga of the Gita, but fails! Sri Krishna reassures him not only by his statement that any effort made in a positive direction is not lost and cannot be seen as failure; and by providing some powerful psychological-yogic techniques that can aid the seeker in gaining control of the unruly mind and the senses. These techniques have been further developed and enunciated in the yoga sutras of Patanjali and are commonly known as “Raja Yoga”. Swami Vivekananda’s book titled Raja Yoga provides a detailed and extensive review of the techniques in a comprehensive form, but the Gita provides the essence of the method, as summarized by Sri Aurobindo:
In this process the Yogin is directed to practice continually union with the Self so that that may become his normal consciousness. He is to sit apart and alone, with all desire and idea of possession banished from his mind, self-controlled in his whole being and consciousness. ‘He should set in a pure spot his firm seat, neither too high, nor yet too low, covered with a cloth, with a deer-skin, with sacred grass, and there seated with a concentrated mind and with the workings of the mental consciousness and the senses under control he should practice Yoga for self-purification….’
“The posture he takes must be the motionless erect posture proper to the practice of Rajayoga; the vision should be drawn in and fixed between the eyebrows, ‘not regarding the regions.’ The mind is to be kept calm and free from fear and the vow of Brahmacharya (roughly translated as “celibacy”) observed; the whole controlled mentality must be devoted and turned to the Divine so that the lower action of the consciousness shall bae merged in the higher peace. For the object to be attained is the still peace of Nirvana.”
Obviously the Gita is not abandoning its focus on an integral, embracing and active realisation unifying the manifest and the unmanifest, so this practice must be seen as a specific and powerful assistance to the process of gaining control over the mind and ego-sense, not as an end unto itself.
Sri Aurobindo, Essays on the Gita, First Series, Chapter 23, Nirvana and Works in the World, pg. 230