The normal action of our minds is like a large train station during rush hour. Thoughts are constantly arising, provoked by perceptions of the senses or due to direct influence of mental vibration on our minds. As a result we become fixated on these outer forms, forces, events and the world that we have created in our minds. When we consider that during the daytime, we are focused on all this world of activity, and we forget about the infinite universe that surrounds us, but with the coming of nighttime the clear sky reminds us of the stars, galaxies, universes beyond, we can recognize the powerful impact of the daily impressions on our focus of attention. The action of mind cannot encompass the infinity or the extension in aeons of time of the Brahman, but experience shows us that when the mind becomes quiet, through meditation, contemplation, or through some form of grace, a new perception of the larger reality of existence can enter and seize our attention.
The Kena Upanishad, in the Second Part, Verse 4 takes up the issue: “When It is known by perception that reflects It, then one has the thought of It, for one finds immortality; by the self one finds the force to attain and by the knowledge one finds immortality.”
Sri Aurobindo comments: “The mind can only reflect in a sort of supreme understanding and experience the form, the image of the supreme as He shows Himself to our mentality. Through this reflection we find, we know; the purpose of knowledge is accomplished, for we find immortality, we enter into the law, the being, the beatitude of the Brahman-consciousness. By self-realisation of Brahman as our self we find the force, the divine energy which lifts us beyond the limitation, weakness, darkness, sorrow, all-pervading death of our mortal existence; by the knowledge of the one Brahman in all beings and in all the various movement of the cosmos we attain beyond these things to the infinity, the omnipotent being, the omniscient light, the pure beatitude of that divine existence.”
Sri Aurobindo, The Upanishads, Kena Upanishad and analysis, pp. 103-104, 165-170