Another issue that arises during the spiritual quest is the determination of “who am I”. The great sage of Arunachala, Ramana Maharshi, used this as the basis of an entire spiritual discipline and realisation. The question of the “individualisation” that we experience eventually has to be taken up, examined and understood.
For most of us, when this question arises, we immediately reflect on the personality that we experience in the mind, life and body we call our own with what has been called the “ego-sense”. We are attached to and identify with this ego, and this leads us to the question of what happens to this ego after death? Is there something that is real and which transcends specific lifetimes? Does it carry awareness of a specific ego-personality with it, or is it something else that moves between lifetimes; and if there is such a mechanism, how does it work.
The ego has an inherent fear of death primarily because of this question of its dissolution. Human beings instinctively know that the ego is transitory and cannot possibly move from life to life having fixed relationships with the friends, family and associates that it has in this lifetime. Some respond by simply denying any reality for some “entity” that persists beyond death and they treat this lifetime as the one and only lifetime and conceive of death as a “big sleep”, or a “dissolution” or in some cases as a wait for some event when this ego-self will be raised up and reconstituted with its friends and family in an afterlife.
The ancient Greeks conceived of an underworld where the individual ego-self went while carrying with it the awareness of the life and relationships it had in the physical world.
The Katha Upanishad focuses on these issues when Nachiketas, the human being sacrificed to Death, has a dialogue with the Lord of Death to find out the secret…but that is a subject for a future discussion.
reference: Sri Aurobindo, The Life Divine, Book 2, Part I, Chapter 3, The Eternal and the Individual, pp. 367-368