What is the possible source of all consciousness? This is the crux of the philosophical inquiry into the vast and ocean-like nature of total human experience to extract the ultimate experience of the Supreme Brahman.
Also central to the issue is the perception of the permanent versus the ephemeral quality of the experience.
The Mandukya Upanishad analyses the waking, dreaming and deep sleep states that every individual is familiar with to arrive at an understanding of the Self that eternally exists, yet remains unknown, Sri K. S. Maheswaran said in a lecture.
The Self is the one who experiences the thoughts and actions in all these states, but is unaffected by these and remains free and pure. It is ignorance in us that makes us identify the Self with the passing and short-lived experiences. These experiences do not have any absolute reality.
The first is the waking state (visva) where there is awareness of the gross world and its activities. The second, the dream state (taijasa), is where the experiences are of a subtle nature since they are felt as mental impressions; the mind alone is active and does not factor the sense organs or the gross body.
The third state is that of deep sleep (susupta), which is also known as prajna; in this state, there is no desire for, or awareness of, the external or the internal world; no thought is felt and only knowledge and bliss remain.
Beyond all these states is the turiya which is the essence of pure consciousness. In fact, it cannot be called a state, because it transcends all states. It has no connection with the finite world.
The revelation experienced in this state is “unthinkable, unnameable and ungraspable,” say the scriptures. The turiya leads to a reality beyond what is known or understood as subject or object. Yet it has a universal validity in terms of human experience and it is communicable in human terms. The Mandukya makes a distinction between the respective experiences. It makes an introspective approach and begins from the sensible and changeable, to the mind which dreams, then to the soul which thinks and finally to the divine within yet beyond all these.