Analytically, one could conclude that essence is category/classification, or the set of the most core properties of a thing, the properties of the thing that aren’t incidental/superficial. This analysis seems to beg for a formal differentiation between the types of properties that are part of the essence and the types that are incidental, but perhaps there are no such categorical differences: the only difference is whether changing a given property makes you think, subjectively, that its “essence” has changed or that it’s a different thing.
One could conclude something similar about the meaning of identity. Are identity and essence equal? Maybe that, too, is a subjective call. One could also say that the “identity” of an object is the set of properties that would have to be equal between that object and another object for those two objects to be considered “identical.” On the other hand, one might posit the same about essence, too.
Going beyond pure analysis and delving into the mystical, essence could be seen as a quality that belongs only to living beings. It would be something akin to a substance, but nonlocal and nonmaterial. It wouldn’t be a set of properties either, but a holistic gestalt of…meaning? It would be “energy” (in the mystical sense), emotion and psyche all at once.
But not all of psyche, only the very core of it, the part one carries/has carried with one after death and before this life, the part of another that one might fall in love with rather than the mere information of their psychology. It would be the aspect of a being that’s most divine and one with God, the part that’s recognized by the Heavens and pervades a million lifetimes and timelines at once. The part that only a big decision can change, the kind of decision that affects the rest of a being’s eternity.
