Starting Metaphors for the Essence/Existence Distinction
No metaphor is perfect but some are enough to get us started in understanding St. Thomas’s distinction between essence (what a thing is) and existence (the fact that a thing is).
The first comes from Barry Miller, who asks us to think of “the homely analogy of a block of butter that has been cut into a number of parts. Each piece of butter has a different surface or bound. A peculiar thing about bounds is that, although they are real enough, they themselves are totally devoid of thickness: they are not to be mistaken for an enveloping film whether of butter or of any other material whatsoever. Despite their ontological poverty, however, they do have a genuine function, for they serve to distinguish every block from every other block. In that sense they can be said to individuate the blocks they bound.”1
This maps on well with the essence/existence distinction made by St. Thomas, for the simple fact that a thing’s act of existence accounts for ALL the actuality of anything that is a REAL being. It could not be otherwise. However, with respect to individuation, a things essence (or definitional bounded-ness) is logically prior to its act of existence. Though with respect to its actuality, a things essence is logically posterior to its act (or instance) of existence.
Take Socrates. The essence Socrates sets the bound for a particular act of existence — it “Socratizes” existence, as it were. Hence, with respect to individuation, Socrates is prior to his act of existence, though with respect to actuality (being present in reality!), Socrates is posterior to his act of existence.
The butter metaphor is helpful because it is obvious that the bound serves an irreducibly important function though it is nothing “over and above” the butter itself. Similarly, essence doesn’t “add” anything to existence (outside existence there is nothing to add!); rather, it restricts and individuates existence. It serves as something of a cut-off. Existence, yes, BUT ONLY THIS FAR, or ONLY TO THIS DEGREE, etc.
Another metaphor is taken from Fr. Robert Spitzer who says, “A conditioned nature can be analogized by the particular content of that particularized act of thinking. Thus, an existing conditioned reality can be analogized by a fusion -- a unification -- of an act of existing (a particularized act of thinking by an unrestricted act of thinking) with a conditioned nature (the particular content of that particularized act of thinking).
Using this analogy, we can see how an act of existing (causal activity of an unconditioned reality) is essential to (shares the same nature with) an unconditioned reality, but is particularized when it unifies itself with (conceives of) a conditioned nature (a content different from itself). We can extend the analogy further by noting that just as a restricted content of thought can be conceived within an unrestricted act of thinking, so also a conditioned reality can be actualized within an unconditioned reality. Just as an unrestricted act of thinking can conceive of a particular restricted thought (within itself), so also an unconditioned reality can particularize its causal activity by actualizing a conditioned nature within itself.”2
From there, just fill in the blanks. For us — that is, any anything apart from God — to be is just (speaking analogously) “to be thought about by God.”
See Barry Miller’s The Fullness of Being, pg. 97-98.
See: https://philpapers.org/rec/SPIACM