Sri Aurobindo makes the case that the two choices for the Reasoning Intelligence, the Buddhi, that are normally available, either an imperfect action limited by the inherent limitations of the mentality, or an abandonment of the active will and nature in order to shift the focus of the consciousness toward a one-pointed spiritual realisation, are neither the only options available for the seeker, nor the ideal option for those practicing the integral Yoga. He proposes a systematic effort that results eventually in the shifting of the standpoint of the consciousness from the mental basis to the gnostic, or supramental basis. This is not something to be achieved suddenly as the gap between the two is wide; rather, there must be a transitional phase whereby the mentality is prepared for the higher light and force of the gnostic consciousness to take charge and illumine the mind.
The gnostic consciousness is a “truth-consciousness”: “That possesses the divine unity and yet or rather therefore can govern the multiplicity and diversity: whatever selection, self-limitation, combination it makes is not imposed on it by Ignorance, but is self-developed by a power of self-possessing divine Knowledge. When the gnosis is gained, it can then be turned on the whole nature to divinise the human being. It is impossible to rise into it at once; if that could be done, it would mean a sudden and violent overshooting, a breaking or slipping through the gates of the Sun…, without near possiblity of return. We have to form as a link or bridge an intuitive or illuminated mind, which is not the direct gnosis, but in which a first derivative body of the gnosis can form. This illumined mind will first be a mixed power which we shall have to purify of all its mental dependence and mental forms so as to convert all willing and thinking into thought-sight and truth-seeing will by an illumined discrimination, intuition, inspiration, revelation. That will be the final purification of the intelligence and the preparation for the Siddhi of the gnosis.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 7, Purification–Intelligence and Will, pp. 645-646