If the seeker is to find a way to escape the bondage of the lower nature, a point of leverage is required that can stand outside the frame of limitation of our habitual patterns of reaction to the impressions of the world. While obviously still part of the human nature, the higher reasoning mind, the buddhi in the Sanskrit texts, provides the best point of leverage and is thus, the power chosen by those who follow the path of knowledge, in their initial efforts. Sri Aurobindo describes this power of mind: “By the understanding we mean that which at once perceives, judges and discriminates, the true reason of the human being not subservient to the senses, to desire or to the blind force of habit, but working in its own right for mastery, for knowledge.”
He advises that due to an admixture of this higher faculty with the rest of the operations of the mind, the sense-mind, the desire-mind, etc., we do not see the kind of pure action of which this faculty would be capable if it were disentangled from the lower workings of mind. “In its purity it should not be involved in these lower movements, but stand back from the object, and observe disinterestedly, put it in its right place in the whole by force of comparison, contrast, analogy, reason from its rightly observed data by deduction, induction, inference and holding all its gains in memory and supplementing them by a chastened and right-guided imagination view all in the light of a trained and disciplined judgment. Such is the pure intellectual understanding of which disinterested observation, judgment and reasoning are the law and characterising action.”
There are also even higher functions of the buddhi that go beyond the powers noted here. “…there is another and a higher buddhi which is not intelligence but visino, is not understanding but rather an over-standing in knowledge, and does not seek knowledge and attain it in subjection to the data it observes but possesses already the truth and brings it out in the terms of a revelatory and intuitional thought. The nearest the human mind usually gets to this truth-conscious knowledge is that imperfect action of illumined finding which occurs when there is a great stress of thought and the intellect electrified by constant discharges from behind the veil and yielding to a higher enthusiasm admits a considerable instreaming from the intuitive and inspired faculty of knowledge. For there is an intuitive mind in man which serves as a recipient and channel for these instreamings from a supramental faculty.”
These higher intimations are normally subject to dilution, admixture and distortion by the ordinary functions and faculties of mind going to work on them, categorizing, organizing, and digesting them as possible, and forming them into thought patterns that are consistent with the habitual mind’s bent or emotional direction. Thus, it becomes necessary to find a way to separate and keep in their purity, the results of this higher functionality in order to gain the full benefit for the yogic process of this higher understanding mind.
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 3, The Purified Understanding, pg. 296-297