In the West, understanding is based on essential definition. We find it in Plato’s cave: the idea that everything we see is a distorted shadow of some Platonic archetype. The essence of reality is ideal forms—an essential “cat,” or “dog,” or “chair”—which our world renders imperfectly in specific examples that vary from that essence to some degree or another.
We also find it in Christian theology, starting with our Fall from perfection in Genesis, but even more particularly in John 1:1, “In the beginning was the Word, and the Word was with God, and the Word was God,” and John 1:14, “And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.” The lowercased flesh is merely a temporary incarnation of the uppercased eternal Word.
This concept of an “essential nature” is behind our understanding of the “soul” that makes us each unique, and not coincidentally why learning something’s “true name” lends magical power over it (traced through Medieval alchemy all the way back to Platonic thought).
In the East, on the other hand, no word could ever encapsulate the eternal. Consider the first two lines of the Tao te Ching, “The Tao that can be spoken is not the eternal Tao. / The name that can be named is not the eternal name.” While an external, eternal reality is assumed to exist, it can never be fully grasped. The goal of existence, then, is not to regain some lost ideal, but rather to accept the flux and be at peace.
And this is why I can never be Buddhist. Buddhism is not a stone to be clutched. And even if it were, one cannot swim with a pocket full of stones. I’ll never be Buddhist because I always already am.