I'm enjoying my re-reading, or re-re-reading, given the highlighting I've done to this book, of Guy Newland's "Introduction to Emptiness: Tsong-Kha-Pa's Great Treatise on the Stages of the Path." It's a brilliant discussion of a core Buddhist notion, defined as the sheer nonexistence of intrinsic nature.
In other words, nothing is intrinsically itself. Everything depends on other things for its existence, us naturally included. Nothing stands on its own, an island unto itself. Interconnectedness and interdependency is how the cosmos works.
So Buddhism is unique among the world's major religions in not positing an eternal soul. (Because it isn't really a religion, though many Buddhists wrongly ascribe religious qualities to their faith.)
Here's two passages from Introduction to Emptiness regarding the imaginary nature of "an eternal and essential self."
Sorry to break it to you, but you don't have one. You, me, everybody -- we all have come into being through causes and conditions that don't last forever, as is obvious from the human aging process.
The language will be a bit unfamiliar, though it is certainly clear. Newland says that no one has ever perceived an intrinsic self, or soul, that is different from the mind and body. That non-existent entity is an imaginary religious concept. Give it up and you'll be closer to grasping the nature of reality.
As noted in the second passage, don't be afraid to give up a belief in an imaginary thing. Grasping after illusion is what keeps us trapped. Let go of fantasy and you'll breathe a big sigh of relief, because the pressure will be off to view yourself as anything other than what you truly are.
A transitory blip of existence, just like everything else in the cosmos. We aren't separate from what surrounds us, but an intimate aspect of it.
Tsong-kha-pa notes that non-Buddhist philosophies about an eternal and essential self arise when their proponents realize that the essential self really cannot be identical to the flux of mental and physical aggregates.
Reaching the wrong inference, they then teach about the existence of a metaphysical self that is essentially different from the mind and body.
However, their own ordinary and conventionally valid consciousnesses never perceive any essence or intrinsic self that is different from the mind and body. This is simply an imaginary construct.
Instead of assuming that there must be a permanent self and then locating it as an essence distinct from the mind and body, they should realize that since an intrinsically existing self can be found neither as one with nor as different from the mind and body, it simply does not exist.
...The Buddha points out the painful and sad futility of our clinging to objects, people, ideas, experiences, and identities that simply cannot be held, no matter how tightly they are grasped.
Because they have no ability to set themselves up and exist on their own, we and the things around us are in flux, changing as conditions change. With no essential nature, neither our own selves nor the things around us have any inner handle by which we can grab and hold them.
We are afraid to face this lack, this emptiness.
Our fear arises from and feeds our grasping, and in this way we build a prison for ourselves, moment by moment. Yet by bravely facing the reality of emptiness, we can let go of our fear, anger, and greed.
We can be free.