According to Vedanta, the fundamental nature of this universe is consciousness and everything else is a manifestation of it. Correspondingly, your true self is consciousness (atman) and the manifestation is ego-self (ahankara). Awareness (I know I exist) comes to us as a function of having this consciousness in us. Awareness is what develops when consciousness goes into the subject-object relationship with itself or with objects around it, the subject being pure consciousness and the object being the manifestation of consciousness – thoughts, memories, feelings and emotions. This subject-object relationship is what produces the awareness that “I exist”. When you deeply think about what is the ‘I’ we refer to, it appears that it is just the accumulation of memories, feelings, experiences, and emotions that you internalized as a function of the mind over the period. You’re the same self that you were as a child, but it is your accumulation of experiences as a function of mind that you’re internalizing which gives the perception that you’re changing. According to Vedanta, the accumulation of thoughts, memories, feelings and emotions is not the real ‘you’, it is just an accumulation or the function of the manifestation, the maya. Your real self is your pure consciousness, the atman. So, in a way, all your behavior is a transformation of the fundamental element, consciousness, also called the universal consciousness.
Science on the other hand defines consciousness as: it is what we lose everyday when we go into a dreamless sleep and what we gain everyday when we get up in the morning. Science says that we lose consciousness everyday at night in a dreamless sleep. Whereas Vedanta says the dreamless sleep feels like there is no consciousness because of a lack of object without which self-awareness (I know I exist) cannot happen. The dreamless sleep is a form of pure consciousness without any object. Consciousness is very much there in your sleep, it is just that you’re not aware of it. In the regular world or in a dreamy sleep, one always has objects for relative reference whereas in the dreamless sleep there is no object. Top neurologists are looking into this (video from Sam Harris below) and science is just getting to understand this deeper and it is difficult to approach it by dissecting and saying that our brain is a bunch of neurons.
The true self, the universal consciousness, is denoted as Self (with an uppercase ‘S’) and the ego or separate self, the self which is the accumulation of all feelings, emotions, memories, actions, etc. is denoted as self (with a lowercase ‘S’). Advaita Vedanta says that the ego is an illusion, it is the accumulation of your objects. The real you should always be an irremovable subject ‘I’, which is why they say that ego is the Maya, the illusion of this world and it only existed in your mind which ceases to exist after death. But the true consciousness continues its existence post the so-called death.
Assume you were born as an infant in absolute darkness and assume that you don’t feel hungry or you’re fed without any externality. All you can see is absolute darkness without an object. Your mind will not exist, it will fall apart because there is no object to identify and relatively identify itself. Mind is a development of relative objectification. But, you can still experience that darkness and the feeling of being alive. So, you’re not your mind.
To look at life this way needs a lot of introspection of your thoughts, feelings and the function of your mind. It needs one to observe deeply what is happening and observe various thoughts, feelings and emotions arise and subdue in the mind. This is why this process requires a silent keen observation of one’s own mind, which is to meditate and separate oneself from all objects so you don’t refer to yourself relative to objects. The so called people who are enlightened or gurus or Buddhas are not those seeking a God, these are people who are seeking for the true self, trying to identify the true self by separating from the manifestation of the mind by separating all objects in the days of isolation (Sanyasi). That state when you realize the true self is called Moksha in Vedanta, because when you realize who your true self is when you will instantly automatically lose interest in karmic desires (of the mind) because you’ll realize that it is not your true self. It is something like understanding gravity, people were living their lives having sex, eating food and wearing clothes before gravity was discovered too. But, once you understand gravity, it changes your perspective of the same thing because you know what is the real reason something is happening. That’s the perspective difference in life that Moksha brings to you. Below are a few sayings on consciousness for you.
Hope this is useful, thank you.