We tend to identify with the perceptions, sensations, desires, feelings and thoughts we experience and through the ego-consciousness, we take ownership of them and believe that they are what makes up our unique individuality. When we sit quietly, and turn our attention away from the outer world, we experience the internal dialogue that takes place as we process all of these impinging forces and their impact on our brain and nervous system. We remain identified with them. Those who tend to be less outgoing, whom we call introverted, remain focused on the external world and its pressures, and their internal process remains very much the same, focused on the thoughts, feelings, etc. related to their ego-personality. None of this represents the ‘witness consciousness’ that Sri Aurobindo describes.and which develops from the separation of Purusha and Prakriti as found in the traditional teachings of the Sankhya.
The Separation of Purusha and Prakriti actually implies that both the external actions and reactions, and the internal review and dialogue that occurs are seen as “external” and separate from the inner being. The Purusha observes but does not get involved nor attached to any of the actions of Prakriti. Prakriti includes both the outer and the inner activity. The Shwetashwatara Upanishad states “Two winged birds cling about a common tree, comrades, yoke-fellows; and one eats the sweet fruit of the tree, the other eats not, but watches.” This more or less describes the relation of the witness consciousness to the active external nature.
Sri Aurobindo observes: “It is not possible to distinguish the psychic being at first. What has to be done is to grow conscious of an inner being which is separate from the external personality and nature — a consciousness or Purusha calm and detached from the outer actions of the Prakriti.”
“There is a stage in the sadhana in which the inner being begins to awake. Often the first result is the condition made up of the following elements: 1. A sort of witness attitude in which the inner consciousness looks at all that happens as a spectator or observer observing things but taking no active interest or pleasure in them. 2. A state of neutral equanimity in which there is neither joy nor sorrow, only quietude. 3. A sense of being something separate from all that happens, observing it but not part of it. 4. An absence of attachment to things, people or events.”
Sri Aurobindo, Integral Yoga: Sri Aurobindo’s Teaching and Method of Practice, Chapter 7, Experiences and Realisations, The Witness Consciousness, pp. 179-181