In another essay, I explain the meaning of “exists” like so:
Existence is a predicate. Existence refers to a concept, or we could not speak of it (by the use of a word “existence”). This concept we either attach to another concept (a concept of an object, such as a chair, or unicorns) or not. E.g. you have the idea of a chair, and you either attach the predicate “existence” to it (i.e., you say either “it exists” or “it doesn’t exist”), or in other words you “earmark” it as being extant or not, based on what you reason and perceive about it. You may have never even seen the chair, and you might say that it exists based upon something you’ve read. You could even have been misled by what you’ve read, yet you still say it exists. And you can’t even claim that something exists or not independently of whether you believe it exists, because you will always necessarily claim that it exists if you believe it exists and that it doesn’t if you believe that it doesn’t, so there is no room in your episteme/ideology to claim an existence-status that could vary from your belief about it, when you believe with 100% certainty.
So existence is clearly a concept. Specifically, it is a statement qualifying what we would expect to perceive or not perceive under various hypothetical conditions, conditions imaginable within the model of reality we hold. For example, “that chair exists” means that if I, hypothetically, will myself to do what I believe is activating my motor neurons in order to do what I believe is “walking over to where the chair,” or if I otherwise find myself in that “location” (“location” also being an idea pertaining to world-model that’s ultimately based upon sense impressions), then I should visually perceive “that chair,” meaning I should perceive some image/visual qualia that I abstractly determine meet whatever criteria are attached to the meaning of “a chair,” as well as other criteria attached to the specific chair in question. For the purposes of Descartes’ argument, though, whether existence is or is not a predicate is only relevant for one reason: Descartes wants to have his cake and eat it too by implying existence to be a predicate and to not be a predicate at the same time. That’s what Kant vaguely, if keenly, picked up on.
In the above argument I don’t necessarily mean to imply that there is no reality outside of our conception of it. What I meant to do is show that, in some sense, “existence” is in fact a predicate—if only in the sense that everything we know about and can speak of regarding reality is necessarily ideational.
But, to veer off into a different, but important, subject: if I wanted to make an argument that “the chair” doesn’t actually “exist” in any sense beyond our knowledge of it, I would say that material reality is a specific pattern of molecules that we arbitrarily segregate into conceptually discrete forms. For example, consider the group of molecules comprising “floor and chair.” At some fuzzy place in that set of molecules, where ‘floor’ molecules and the “chair” molecules intermingle, we say “the floor” ends and “the chair” begins. In reality it’s all just a large group of molecules, and it simply suits our purposes to consider it as two separate, discrete objects, and there isn’t even an absolutely exact boundary at which “the floor” ends and “the chair” begins. Is a splinter on the chair part of the chair? Is the paint on it part of the chair? What about the flake of paint that’s about to fall off? What about the flake that just did fall off? Is the rust on it part of it? The dirt left from sitting on it? Etc. It’s all arbitrary.
Now, instead of considering only the particles/energy-patterns composing ‘the chair’ and ‘the floor’, extend that concept to the universe a whole. Now all objects are merely concepts afforded by arbitrary delineations, except for two things: The universe, and individual molecules. And even molecules are, of course, made of even smaller particles (atoms), which are in turn made of even further smaller particles (subatomic particles), some of which are made of a) smaller particles (such as quarks), and b) nobody even knows. Even subatomic particles are not solids with clearly defined borders, as any physicist will tell you; it all boils down to fields. The presence of an electron, for example, actually tapers off gradually with distance. And particles are thought to be local excitations in fields that extend everywhere in space. Quantum entanglement even puts into question the actual separateness of things that are differentiated from each other by their locations. When you get down to string theory would, it almost seems as though the universe is supposed to be made out of pure math. So even imagining that the universe composes a set of objectively-discrete entities called ‘atoms’ (or whatever scale of entities you want to use as a base) doesn’t really work.
Then there is the second part to the argument that ‘the chair’ doesn’t exist beyond our knowledge of it: anything we can know of, insofar as we can know of it and therefore can speak of it, can only be ideational/mental, as knowledge is ideational. (We can also say ‘mental’, ‘conceptual’, ‘cognitive’ or whatever other word that does not seem too limiting.) Our entire understanding and definition of “the chair,” including all its attributes, is ideational. Whereas ‘external reality’ cannot be not ideational–or at least it’s presumed not to be, unless you subscribe to a theory that the entire universe is mental in nature. We’ll assume it isn’t for the sake of the argument, because that’s what most people believe. Since any two things we can compare must be ideas (inasmuch as we can even compare them), the difference between the ideational and the non-ideational (that is, “external reality”) is necessarily of a higher order than any difference we can comprehend. Given that fact, to presume that such ‘reality’ has anything like what we think of as ‘a chair’ in it seems to be a shot in the dark, at best.
I actually believe consciousness is primary and that matter is in some way a derivation of consciousness, I just wanted to take the common conception to its logical conclusion. However, it’s possible that whatever super-mind(s) or super-consciousness(es) the universe belongs to doesn’t particularly think in terms of chairs and floors..
In yet another essay, I explain “exists” like this:
The concept of “existence” is a tricky one. Emmanuel Kant said, in response to the ontological proof of God’s existence, said that “existence is not a predicate.” While his reasoning surrounding this statement was valid, the statement alone isn’t exactly true. Existence is a predicate, it’s just not a normal one. If existence weren’t a predicate, why would we say that a unicorn—or anything else—is either “existent” or “non-existent”? That’s exactly how predicates work.
You could say that the unicorn that’s non-existent can’t have any predicates because it doesn’t even exist, but if you think about it, all objects we can possibly think or talk about are mental objects; they exist primarily in the mind. They may or may not “point” to objects outside of us.
How do we know if a mental object points to something outside of us? Presumably, we can’t directly know of anything that exists outside of our minds. We only infer as a result of sensation. So how do we know the chair exists even while we’re not sensing it? If we expect that, when we will our muscles to contract in certain ways we call “walking into the dining room,” we will see a chair with specific properties there, then we say that that chair “exists” and that our concept of the chair therefore points to something outside of us. But insofar as we can think of or talk about the chair, it exists in our minds.
We don’t even know if reality outside of our minds (if there is such a thing) is made of objects, or if it’s just some continuous field that wouldn’t even look like objects if we could have a “view from nowhere” (or, to be more epistemologically coherent, at least a “more objective” viewpoint). Indeed, “the chair” is just an arbitrary collection of atoms that we separate as “a chair.”
Let’s say the chair is made of wood and, due to attrition, some wood particles on the bottom of the chair’s legs get scraped onto the floor. Exactly which particles belong to the chair, and which belong to the floor? Where does the chair end and the floor begin? What if a child marked the chair 3 years ago with a magic marker? Are those ink particles now part of the chair, or not? If you break apart the chair with a hammer piece by piece, or burn it to the ground, at what point during the process does it cease to be a chair? Etc.
Since any two things we can possibly compare and contrast to each other (presumably using thought) must necessarily be ideas, the schism between the ideational (that in our minds) non-ideational (that outside of us) must necessarily be the biggest possible schism we can imagine—or, arguably, bigger than any schism we can possibly imagine.
So, back to the existence of the chair. To say that it exists is necessarily merely to say that we expect to perceive particular sensations in response to willing (what we think are) our muscles to do certain things. (We don’t know for certain that we have muscles, but we know for certain what we’re willing since that’s a part of our mind and therefore is directly known.)
If you posit something extant that can’t possibly affect us, any possible description of that thing is equally valid, since none of it is provable/demonstrable or falsifiable.
So, to validly posit that something “exists” must imply positing that it can potentially affect us in some way. If we will X, we expect to sense Y, hence Z exists. E.g., if we will walking to the dining room, we expect to have the visual sensation of a brown geometric form whose shape is determined by our perspective, hence the wooden chair exists. Of course, there are a million other ways we could less directly test its existence, and we can guess they’d all work because reality seems to be self-consistent, but that’s beside the point.
One problem with the above descriptions is that they only account for physical objects, yet we may claim that some nonphysical things, like souls, exist, or that some abstract things, like numbers, exist too.
I think that the more general answer to the question of “exists” is that it’s intimately connected with object permanence. Perhaps our concept of conceptualization of existence is connected with object permanence because it’s one of the first things we learn about how the world works. Perhaps it’s also how we realize that things persist independently of our current thoughts about or perceptions of them.
“But numbers don’t have object permanence!”, you say. Well, I’m talking about a more generalized kind of object permanence, one which I might call “concept permanence.”
The number “1” seems to have concept permanence in that you can stop thinking about it, then come back to it, and it’s still there (in your mind) in exactly the same way. It seemingly doesn’t change one bit from mental invocation of it to another.
Furthermore, “1” seems to be discovered rather than arbitrarily imagined. Even though we don’t perceive it sensorially, it seems discovered because it’s an integral element of a framework that’s integral to how we think/how we model and manipulate reality. I.e., we group objects together according to similarity or proximity or something else they have in common that makes the grouping useful, and the cardinality of that group is the number “1”, or “2”, etc.
And, if you were to take “1” out of the picture, you could immediately deduce its “existence” again using math—algebra, arithmetic, whatever. This is another facet of its apparent object/concept permanence. You totally remove it from your mind, then you go looking for it, and there it is again. Not that you could really forget the number “1” even if you wanted to, but if you temporarily pretended it was just something arbitrarily imagined, you know you would soon be proven wrong.
Not that I think numbers really do exist anywhere but in the imagination, as I explain in https://myriachromat.wordpress.com/2019/09/21/why-mathematical-platonism-is-silly/.
That last sentence, by the way, opens a whole other can of worms: why do we say things exist if they’re not merely imaginary, unless we say they “exist in the imagination” or something “exists as a concept”? What does “exists” mean in that case? Maybe it comes from casting the entirety of the imagination as if it were a world of its own, in which case the imaginary concept exists “in that world”?
Or maybe we imagine that we take a freezeframe of the person’s mind with the imaginary element in it, thus seemingly stripping it of its ephemerality that’s otherwise intrinsic to imaginary entities?
Or maybe in this case we use a looser conception of “exists” that doesn’t require the element of discovery or object/concept permanence, but merely the element of being regarded (in this case, by the mind’s eye), because we reason that it must have some kind of existence or exist somewhere or else how would we possibly know about it?
Then there is the issue, as mentioned above, of something like a soul being considered to “exist” (inasmuch as the concept of the soul is itself considered to be legitimate). Does it have object permanence? I guess we imagine it to.
To be honest, another factor in whether something is considered to exist or not, besides object/concept permanence, is probably its apparent objectivity, by which I mean its propensity to be discovered in the same way by others (as believed by the beholder). But it’s hard to think of a case where this property would exist without the property of object/concept permanence or vice versa.
That’s all I have to say about existence.