The principle and basic mode of operation of the human mental being is vastly different from that of the spiritual being. Spirituality is not some kind of advanced or refined intellectuality; rather, it is a completely different level and order of consciousness with its own distinct way of knowing and acting. In most ways, it seems to be the “opposite” of the mental mode.
Sri Aurobindo sets these two side by side: First the spiritual being: “To the former belong infinite being, infinite consciousness and will, infinite bliss and the infinite comprehensive and self-effective knowledge of supermind, four divine principles…” Next the mental being: “…to the latter belong mental being, vital being, physical being, three human principles.”
“The divine is infinite and immortal being; the human is life limited in time and scope and form, life that is death attempting to become life that is immortality. The divine is infinite consciousness transcending and embracing all that it manifests within it; the human is consciousness rescued from a sleep of inconscience, subjected to the means it uses, limited by body and ego and attempting to find its relation to other consciousnesses, bodies, egos positively by various means of uniting contact and sympathy, negatively by various means of hostile contact and antipathy. The divine is inalienable self-bliss and inviolable all-bliss; the human is sensation of mind and body seeking for delight, but finding only pleasure, indifference and pain. The divine is supramental knowledge comprehending all and supramental will effecting all; the human is ignorance reaching out to knowledge by the comprehension of things in parts and parcels which it has to join clumsily together, and it is incapacity attempting to acquire force and will through a gradual extension of power corresponding to its gradual extension of knowledge; and this extension it can only bring about by a partial and parcelled exercise of will corresponding to the partial and parcelled method of its knowledge. The divine founds itself upon unity and is master of the transcendences and totalities of things; the human founds itself on separate multiplicity and is the subject even when the master of their division and fragmentations and their difficult solderings and unifyings.”
These are represented by two hemispheres, separated by a golden veil or lid. As a result, the human consciousness has no direct access to the upper divine hemisphere usually. The Isha Upanishad (v. 15) states: “The face of Truth is covered with a brilliant golden lid…” For most human beings, tied to the mental framework, there is both the failure to recognize this separation and that another entire hemisphere of consciousness both can and does exist, and the inability to break through that veil or lid. The practice of Yoga is intended to achieve such a result so that the human seeker can take on the consciousness of the Divine through knowledge by identity.
Sri Aurobindo, The Synthesis of Yoga, Part Two: The Yoga of Integral Knowledge, Chapter 13, The Difficulties of the Mental Being, pp. 376-377