The powers of mind that are possible when the highest reaches of the mental plane are attained represent capabilities far beyond what we ordinarily experience within the limits placed upon mind by its association with the body and the vital life energy. Those seeking perfection of human life strive to incorporate these higher powers of mind and even a small modicum of success is counted as an enormous progress. At the same time, Sri Aurobindo reminds us that these powers of the mental plane still suffer from the inherent limitations of the mental plane itself, and that there remain levels of awareness and conscious existence that go beyond the mental plane and thus, are freed from the inherent limitations.
Commenting on the ultimate possibilities on the mental plane, Sri Aurobindo observes: “For here too our spiritual realisation would be subject to the limitations of the mind which is in the nature of a reflected, diluted and diffused or narrowly intensive light, not the vast and comprehensive self-existent luminosity and joy of the spirit. That vaster light, that profounder bliss are beyond the mental reaches. Mind indeed can never be a perfect instrument of the Spirit; a supreme self-expression is not possible in its movements because to separate, divide, limit is its very character. Even if mind could be free from all positive falsehood and error, even if it could be all intuitive and infallibly intuitive, it could still present and organise only half-truths or separate truths and these too not in their own body but in luminous representative figures put together to make an accumulated total or a massed structure.”
This leaves only the option to abandon the body-life-mind to achieve a station in a higher plane of existence that does not suffer from these deficiencies, or to find a way to integrate the higher plane into the world in a way that has not yet been developed and is thus not yet obvious.
In the past, those who have achieved a breakthrough to the next planes do not return to the earth-plane. They simply evolve beyond and leave this life behind. “He cannot bring down its greater spiritual nature into this lower triplicity; for here the mental being is the highest expression of the Self. Here the triple mental, vital and physical body provides almost the whole range of our capacity and cannot suffice for that greater consciousness; the vessel has not been built to contain a greater godhead or to house the splendours of this supramental force and knowledge.”
This does not mean that the quest to integrate these higher planes of the Spirit is impossible to fulfill; rather, it means that a new path and method must be developed in order to accomplish this task.
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 21, The Ladder of Self-Transcendence, pp. 452-453