Atman or the Cosmic Self has a three-fold nature. It has a subject or observer aspect, the process of observation, and the object or observed aspect. I illustrated this here.
As consciousness is aware of itself both globally and at every point, it can observe its own dynamics and experience this directly.
“Locally” or personally, we experience this as the ego or I-sense, the intellect, and the mind.
Samkhya describes how Buddhi (intellect) recognizes self as different from other, creating Ahamkara, the I-sense or ego. This arises in early childhood as a baby distinguishes itself from mother.
Manas or mind is the object of Ahamkara, the field of other or not-self per the intellect. We might think of mind as the screen or stage on which our inner world plays. We may see thoughts as mine but are usually unaware of the field of mind itself. In a deeper sense, mind is just lively consciousness, perceived by an identified I-sense as within and local.
In other words, consciousness may seem very abstract but it is the foundation of all our experiences, both locally and cosmically.
From a broader perspective, there is no personal ego, intellect and mind. They are cosmic or universal functions that have a local focus here. It is our identification with those experiences relative to this body that causes us to see them as local and “mine.”
This is a natural part of becoming a distinct being in childhood. But without the right influences we get stuck there, limited to a local sense of self.
Diving beyond the mind and intellect in practices such as meditation, we touch consciousness itself and gradually become familiar with our cosmic nature. This loosens the bonds of identification with individuality until we are liberated and realize our cosmic nature.
And that begins a new journey through our eternal, infinite cosmic self.