Ontological existence seems to be distinguished from nonexistence as being a member of some set. — noAxioms

Is this about existential quantification?

If so, then to exist is to be an element in the domain of discourse; roughly, to exist is to be spoken of.

Russell's paradoxes show the deficiencies of set theoretical interpretations of first order schemes.

I was thinking:
a) 7 is a number, same as 8. To say 7 is prime or 8 is even is to state some knowledge that describes properties of these numbers. As product of knowledge, what it is to be a prime number, has no effect on their assumed 'ontology'
b) The set of primes is separate from the rest of the sets of numbers, yet what it excludes both limits it and helps define the set.
c) To say the universe is this or that, is not viciously circular, since we have no independent viewpoint.

Is this about existential quantification?

If so, then to exist is to be an element in the domain of discourse; roughly, to exist is to be spoken of. — Banno

I had not meant it to be about existential quantification, but my attempts to sort this out come to this quite a bit: I have a base aversion to idealism, so I stay away from statements implying observation or discourse being the thing distinguishing an objectively actual structure (maybe that's a better word than 'set') from a non-actual one. But it comes up a lot, sort of a circular ontology of mind supervening on the material, but the ontology of the material somehow supervening on that observation.
Sorry about that statement. I can barely parse it myself. Language fails me trying to express this issue.

Russell's paradoxes show the deficiencies of set theoretical interpretations of first order schemes.

I should give em a look.

I was thinking:
a) 7 is a number, same as 8. To say 7 is prime or 8 is even is to state some knowledge that describes properties of these numbers. As product of knowledge, what it is to be a prime number, has no effect on their assumed 'ontology' — Cavacava

I am not referring to knowledge of the structure, but rather the objective (independent of knowledge or observation) reality of the structure. Is the structure of the set of primes dependent on knowledge of it? Quite possibly so it seems, even if that makes it an idealistic distinction, But seven being a prime is true regardless of said knowledge.

b) The set of primes is separate from the rest of the sets of numbers, yet what it excludes both limits it and helps define the set.

Point taken. The structure of whole numbers would need to exist to give meaning to the primes and the numbers that are not. The primes exist as part of that set, and that set part of rational numbers and so forth in a sort of heirarchy of supersets. Is there a bottom to that? Is our universe just a member of (an actuality in) some larger structure of things (like inflation bubbles for instance)? My question still stands then about that superset, unless there is no bottom to the regression.

c) To say the universe is this or that, is not viciously circular, since we have no independent viewpoint.

Hence my choice of a structure other than this universe we know. I am not a member of that structure (I am not a prime), so I have sort of an independent viewpoint of it. Similarly, inflation theory posits all these different universes with different tunings of the various cosmological constants, and in almost all of them, they have the wrong number of macro dimensions or wrong forces for anything coherent like matter to form. They cannot be observed, do not exist in any sense of the term 'now', yet it would seem to be a violation of consistency for them not to share our own ontological status.

I have a base aversion to idealism, so I stay away from statements implying observation or discourse being the thing distinguishing an objectively actual structure (maybe that's a better word than 'set') from a non-actual one. But it comes up a lot, sort of a circular ontology of mind supervening on the material, but the ontology of the material somehow supervening on that observation. — noAxioms

Per realism, that we can observe or point to something is not what makes that thing exist (which is a separate question), but it is what allows us to claim that it exists. We aren't confused about the ontological difference between our universe and the Harry Potter universe because we can point to the books and the author from where those ideas derive and we understand their history. That gets more complicated with mathematical theories of our universe (or historical and religious accounts) largely due to the fact that some aspects are not readily observable.

Ontological existence seems to be distinguished from nonexistence as being a member of some set. So my car exists if it is a member of things that are in this universe — noAxioms

So you want set and set membership to be the starting point, and to define existence in terms of those. Something exists if it is a member of some special set U.

How do we define U? Here's where you start to have trouble, because so far you've only defined U as "the set of all things that are members of U." That's not going to help much. Obviously, you can't define U as "the set of all things that exist," because then you do have circularity.

So what's the next move? How could you define U in a way that does some work?

Yeah, I don't understand the significance of being a member of some set. If some means any, then anything you can name is a member of any number of sets. If it is some particular set, then the burden of definition is shifted to defining that set.

Per realism, that we can observe or point to something is not what makes that thing exist (which is a separate question), but it is what allows us to claim that it exists. We aren't confused about the ontological difference between our universe and the Harry Potter universe because we can point to the books and the author from where those ideas derive and we understand their history. — Andrew M

I want to agree, but I think where I differ is the claim. If this universe did not exist, I would still be able to point to it. I would just not exist along with it. The universe existing seems not to be a prerequisite to its occupant pointing to it. Harry Potter can point to stuff in his universe despite both their nonexistence. I'm not confused about the difference between the two, but Harry is. Maybe he reads a fiction book about us.

So you want set and set membership to be the starting point, and to define existence in terms of those. Something exists if it is a member of some special set U. — Srap Tasmaner

No, the U is arbitrary, and usually means all that stuff I see, and all the rest that is implied by it. The far side of the moon exists despite the lack of its direct accessibility to any of my five senses.

What I am questioning in this thread is what distinguishes U itself from existing or not, especially absent a member-observer being aware of some portion of the contents of the U. Not asking why U exists and certainly not how it 'became to exist', but what it means at all. Is there an objective fact to the matter, despite the lack of anything that can actually know said objective fact?

I looked up all sorts of articles from the various philosophers, and they seem more concerned with what classes of things exist, and which are excluded. Does love exist? Depends who you ask. But nobody seems to address what it means to exist in the first place, at least not in a way that can be applied to our universe itself. So quantum MW interpretation says there is another universe with an earth where life never began. Assuming the MW interpretation is correct (is there an objective correct answer???), does such an alternative world exist? The only distinguishing difference would be the absence of observers on Earth, and it would seem to be idealism to suggest that what makes this world exist but not that one.

No, the U is arbitrary, and usually means all that stuff I see, and all the rest that is implied by it. The far side of the moon exists despite the lack of its direct accessibility to any of my five senses. — noAxioms

Hey look! You did it. You could define U as "all the stuff I see, and all the rest that is implied by it." Would love be a member of U? Would our universe? (Don't assume U="our universe.") Would stuff implied by the MW interpretation? Would the set U be a member of itself? (Sometimes that's okay.)

I know you want to skip ahead. Your real question is, "If existence means being part of our universe, what does it mean for our universe--or some other one--to exist?" Slow down. Look carefully at the words you're using, at how you're using them, and think through it.

No, the U is arbitrary, and usually means all that stuff I see, and all the rest that is implied by it. The far side of the moon exists despite the lack of its direct accessibility to any of my five senses. — noAxioms

This delineation, however, does a disservice to the form of realism that noAxioms wants to uphold: one that does away with all possible notions of idealism. Because this definition of U depends on awareness in order to hold, it opens doors to idealistic notions.

Since the concept of objectivity has been used, maybe the crux of the problem can be formulated in terms of defining (via awareness) what an awareness-devoid objectivity is—this in the abstract sense, and not in the concrete sense, such as in a physical world predating the existence of physical life. By extension, resolving this would then serve to resolve what an awareness-devoid (hence, objective, in this sense of the word) existence of U consists of. Otherwise, the concept of objectivity becomes entwined with notions of awareness such as those of impartiality; such as where the confirmation biases of aware beings become optimally minimal as regards that which is concluded. This philosophical impartiality applying both to what can be made directly available to awareness as well as to what is inferred from the data of our direct awareness—e.g., the inference that the far side of the moon exists. (Both means of interpreting objectivity can result in an objective physical reality that is regardless of what any awareness might want to make of it—but the latter approach becomes amenable to some forms of idealism, namely those that incorporate the notion of an objective (or, 100% impartial/selfless) reality.)

From the OP:

But my question is more about what distinguishes this universe from a nonexistent one. — noAxioms

It could help out to better pinpoint what is intended by the term “existence”. For example, as mentioned in Wikipedia, existence can be classified into the “wide” and the “narrow” sense. In the wide sense of existence, anything that holds any type of being (or presence) can be stated to exist. Figments of the imagination, such as fictional characters, then exist in the wide sense. In the narrow sense, only that which pertains to objective reality (but see the aforementioned for different approaches to what this could imply) can be stated to exist. Harry Potter, then, does not exist in the narrow sense. Then questions can be posed such as the following: does QM MW exist in the narrow sense, or only in the wide sense?

As a related example, existence could either entail the set of “that which is distinguishable from some background” (this being in line with the literal translation of “standing out”) or the set of “that which holds any sort of presence” (e.g., hypothesizing the Buddhist notion of Nirvana, the state of Nirvana would only exist in the latter sense and not the former). The universe—here presuming it equivalent with everything that exists in the wide sense—can be argued to not exist in the first sense just mentioned: it has no background against which it can be distinguished. This conception of the universe, then, can be argued to exist only in the second sense just mentioned. To me this implies that U can exist only as a member of itself. The only way I can find to avoid this conclusion is to grant existence in the wide sense a background of nothingness (also in the wide sense)—but, then, it seems that this would endow nothingness in the wide sense with substantial presence: thereby making nothingness too an aspect of existence in the wide sense. Hence, again leading to the conclusion that set U can exist only as a member of itself.

Otherwise, it can be stated--as another example--that this universe exists in the narrow sense by standing apart from all other universes which exist a) only in the wide sense (but not the narrow) or b) in the narrow sense but in some way that is different from this universe. (I'm in favor of upholding there being only one universe, though.)

[Work has me fairly busy nowadays (not a bad thing), so I don’t know how I’ll do with follow up posts if replied to.]

If so, then to exist is to be an element in the domain of discourse; roughly, to exist is to be spoken of. — Banno

To be an element of the domain of discourse and to be spoken of are not the same.

I want to agree, but I think where I differ is the claim. If this universe did not exist, I would still be able to point to it. I would just not exist along with it. The universe existing seems not to be a prerequisite to its occupant pointing to it. Harry Potter can point to stuff in his universe despite both their nonexistence. I'm not confused about the difference between the two, but Harry is. Maybe he reads a fiction book about us. — noAxioms

When we say that Harry Potter can point to stuff, we are making a different kind of claim to when we say that we can point to stuff. The latter is understood in a straightforward literal sense, the former assumes we are talking about a work of fiction. That is, our interpretation of those claims already depend on us making a distinction between what exists and what is mere representation. That distinction is enough to provide a usage for the word "exists".

You mention that you are not confused about the difference between the two. But whether Harry Potter is confused is only a question of whether the author represents him as confused or not.

What I am questioning in this thread is what distinguishes U itself from existing or not, especially absent a member-observer being aware of some portion of the contents of the U. Not asking why U exists and certainly not how it 'became to exist', but what it means at all. Is there an objective fact to the matter, despite the lack of anything that can actually know said objective fact?

We distinguish it, we find meaning in it, we live in it, we give nature a point of view that's "what it means at all". Science tells us that the universe existed for eons without us, but its existence was meaningless without us, we assert meaning into an indifferent universe. The only alternative to this is the belief in god whose viewpoint (immanent, transcendental or both at the same time) is indeterminable. The universe has a point of view, and as far as we know, we comprise it, even if it is imperfect, it's all its got :)

When we say that Harry Potter can point to stuff, we are making a different kind of claim to when we say that we can point to stuff. The latter is understood in a straightforward literal sense, the former assumes we are talking about a work of fiction. That is, our interpretation of those claims already depend on us making a distinction between what exists and what is mere representation. That distinction is enough to provide a usage for the word "exists". — Andrew M

OK, the Harry Potter stories (be they conveyed in books, films, plays, whatever) are representations, all forms of language, allowing us to share a vision Rowling's alternate world in our minds. The 'real' world can similarly be said to work the same way. The senses we take in are just different languages, letting us create a model of the world in which the characters in the model point to things. We presume in the direct-sense way that the story our senses tell us are real, that the characters 'exist'. No proof of this exists, but it degenerates into solipsism to assume otherwise. With fiction, there is no such assumption. The world depicted is perhaps a real one, the London/England we know, but an alternate world in which perhaps some quantum collapse back a thousand years unlocked some new gene in a subset of humans that unlocked access to what us muggles would consider supernatural powers, invoked with Latin utterances apparently. The Harry in that world (completely inaccessible to us) can point to stuff, and his ability to do so does not demonstrate (to what??) that world's existence.

Similarly, perhaps our world is a fictional one depicted in stories in Harry's world. There can be no test of it, but I was wondering if it was meaningful to ask what it would mean, without asking to what it would be meaningful to.

You mention that you are not confused about the difference between the two. But whether Harry Potter is confused is only a question of whether the author represents him as confused or not.

The representation is only that, I admit.

In terms of antinatalism, it is interesting to know that you need existence to know that non-existence is preferable. However, non-existence does not seem like something that can exist in and of itself. So, how can anything be purely non-existence by itself without an existence to compare it to? Existence entails non-existence but non-existence itself does not seem to make sense. Perhaps non-existence is pure possibility without being actualized? Then again, what is pure possibility as that seems to be "something" and thus has an existence.

If so, then to exist is to be an element in the domain of discourse; roughly, to exist is to be spoken of. — Banno

Something's not right here. Has LGU clockwork oranged Banno?

Science tells us that the universe existed for eons without us, but its existence was meaningless without us, we assert meaning into an indifferent universe. — Cavacava

Science might say that events (things, matter, whatever) existed in the universe for eons without us, but it does not offer an opinion on the philosophical topic on the table here. I'm asking if there is an objective fact-of-the matter, independent of our ability to find meaning in it, or our ability to detect it.

In terms of antinatalism, it is interesting to know that you need existence to know that non-existence is preferable. — schopenhauer1

Wrong kind of existence, but I see what you're saying. Given the right kind of existence, I'm not convinced that the logic here applies. I exist (wrong kind) in this universe, but this universe seems not to need to exist (right kind) in order for its occupants (us) to know that existence is preferable. Absent a distinction somewhere, the 'right kind' of existence cannot have relevance. Humans instinctually consider the universe to have properties of other objects with which we are familiar, such as a tulip, and thus requires coming into existence, and perhaps sharing existence with other existing things but not with the nonexistent ones. I recognized that misapplication of instinct, and am trying to build it back up on more solid footing.

[/quote]However, non-existence does not seem like something that can exist in and of itself. So, how can anything be purely non-existence by itself without an existence to compare it to?[/quote]It would seem to be a property, no? There can be no pure-warm property without a thing to which the property can be applied (a lit candle say), and something other thing with which to contrast it (un-lit candle). I can do this with objects. A tulip exists in my yard, and the pink elephant does not. Hmm, my logic sort of fails, since the pink elephant seems to need to exist at least so far as to permit the application the property of nonexistence.

Existence entails non-existence but non-existence itself does not seem to make sense. Perhaps non-existence is pure possibility without being actualized? Then again, what is pure possibility as that seems to be "something" and thus has an existence.

You're going down the same path I see. The pink elephant is for whatever reason possible, and hence can have the property of nonexistence. What doesn't get that far? Maybe what makes the pink elephant possible (but not actual) is what makes our universe distinct from one that is not possible.
I think, therefore I'm possible. Ewww, but maybe...

javra, getting to yours. I too have finite time to digest it all.

Science might say that events (things, matter, whatever) existed in the universe for eons without us, but it does not offer an opinion on the philosophical topic on the table here. I'm asking if there is an objective fact-of-the matter, independent of our ability to find meaning in it, or our ability to detect it.

Science may not offer an opinion on whether or not what exists, exists independently of us, but philosophically & objectively we form opinions based on the data science presents to us about our empirical world. Science's rendition of the universe's ancestral history, has & needs no human manifestation, what existed in reality was prior to and independent of our existence. So yea, there is an objective "fact of the matter", it existed prior to us, and I don't see a reason to suppose this independence has changed because we appeared on the scene.

You're going down the same path I see. The pink elephant is for whatever reason possible, and hence can have the property of nonexistence. What doesn't get that far? Maybe what makes the pink elephant possible (but not actual) is what makes our universe distinct from one that is not possible.
I think, therefore I'm possible. Ewww, but maybe... — noAxioms

Can you explain this more?

Yeah, I don't understand the significance of being a member of some set. If some means any, then anything you can name is a member of any number of sets. If it is some particular set, then the burden of definition is shifted to defining that set. — SophistiCat

That last bit was where I was headed. Would have been clearer if I had said "a special set, let's call it U." That's what @noAxioms seemed to want to do, and I was just helping him along, as it turns out, mistakenly.

javra, getting to yours. I too have finite time to digest it all. — noAxioms

Hey, no worries.

Been thinking about this some more: potential categories of existence and inexistence. You’re right, it’s a hefty topic … one I’m still muddling my way through. But I’ll wait for your replies to see where the discussion is going.

So yea, there is an objective "fact of the matter", it existed prior to us, and I don't see a reason to suppose this independence has changed because we appeared on the scene. — Cavacava

Though a bit off-topic, I wanted to comment:

I’m on board with the general perspective you’ve mentioned: namely, that what our collective, most impartial views and inferences inform us of is that live evolved from out of nonlife (though more complex, it’s akin to the inference that the moon has a far side). Nevertheless, if metaphysics is to be understood as a study of being at large as abstraction, this rather than the study of physical being as concrete particulars (such as the study of the nature of causation rather than arriving at concluding inferences of particulars drawn from uncontemplated notions of what causation is) … then there can be found reasons to uphold a metaphysical (though not necessarily physical) primacy of awareness. Will anyone honestly contend that the presence of awareness is not itself an objective fact of our existence? How does the strength of this experiential objective fact then compare with the strength of any inference concerning our physical objective reality—this when the two propositions are compared side by side and are to any extent contradictory? I’m here intentionally avoiding an argument for the metaphysical primacy of awareness on epistemological grounds, though I do intend to allude to at least some means in which this conclusion can be obtained (and, though you and me would be implicated in this metaphysical primary of awareness, the latter is not about you or me as individual beings [unless one desires to uphold the vacuous dogma of solipsism]).

As to the resulting apparent contradiction: what can I say? There currently appears to be a contradiction between a metaphysical primacy of awareness and life evolving from nonlife; but, as with many paradoxes, philosophically resolving this paradox in a manner harmonious to the truths of both sides could bring us closer to deeper truths about our universe and ourselves. My current ballpark guesstimation—to present a rough idea of what I’m entertaining—is that awareness can become more diffuse as it can also become more acute and of greater magnitude (e.g., the awareness of a bacterium is vastly more diffuse than the awareness of a human); in some ways parallel to pansemiosis, it could then be feasible that awareness at its most diffused extreme consists of nonlife.

But again, despite these apparent incongruities, there are indeed reasons to uphold the metaphysical primacy of awareness. When push comes to shove, these reasons take precedence, imo.

You could think about existents, or represent them, as members of a set, but I'd be careful to avoid saying that set membership is what it is to exist. In my opinion it's not very different than considering some dance you might do to represent existence. You'd want to be careful to avoid saying that what it is to exist is to have something to do with the dance.

Why would we need give some other condition or criterion for what it is to exist? And for whatever condition or criterion we give, why wouldn't we have to then give another condition or criterion for that? Why would something be a satisfactory stopping place, but "exist(ing)" isn't?

Mathematical objects and sets only exist as ideas that individuals have.

Potentials, as well as possibles that aren't actualized, do not exist.

Metaphysics is about Being, First Principles, the concept of necessity, which is why Kant following Hume demolished Descartes's ontological proof of god. Thought cannot confer being, because being is not a predicate, a perfect being does not have to exist by virtue of its being perfect. I think absolutes/universals/transcendentals must exist epistemologically, in order for there to be knowledge, but I do not agree that the structure of the world is necessarily the same as the structure of thought.

If I understand what you are saying: 'mind' evolved by means of material evolution to the point of self-awareness, but it is only by virtue of this self awareness that we became aware of this material evolution. I don't think this is contradictory. I think thought as self-awareness, the unity of apperception is a mode that matter has the potential to assume given the correct composition, as it is in us ...a kind of panpsychism that asserts thought as possible mode of matter.

Similarly, perhaps our world is a fictional one depicted in stories in Harry's world. There can be no test of it, but I was wondering if it was meaningful to ask what it would mean, without asking to what it would be meaningful to. — noAxioms

OK, per hypothesis, there would be a (Many-Worlds) quantum world where a real Harry Potter exists as well as the Harry Potter fictional stories in our quantum world. Similarly, there would be fictional stories in Harry's world that just so happens to describe our world.

In this case it would be true to say (justification aside) that Harry Potter existed somewhere in the universe, though not in our quantum world. We would just need to be careful to keep our claims about the real Harry Potter in the other world distinct from claims about the fictional Harry Potter in our world. Similarly for Harry's claims about us.

...a kind of panpsychism that asserts thought as possible mode of matter. — Cavacava

Interesting way of putting it. No, you’re right, this approach need not be contradictory. I get bogged down in the details, though. And, as I expressed previously, when push comes to shove I’ll uphold the metaphysical primacy of awareness (and will) over all other perspectives.

Yes, I’m not big on Descartes’ proof of God either, nor with much of his metaphysics, for that matter.

As to nature following the structure of though … my own tendency is to think that what we term laws of thought - such as that of noncontradiction (X cannot be not-X in both the same way and at the same time) - manifests within our thoughts as they manifest in nature at large, of which our minds are a product of. I strongly disagree with the nature vs. human intellect divide that many metaphysics uphold, Cartesianism very much included among these.

Oddly enough, though, I have a large intuitive bias against panpsychism. I can’t yet make sense of it. I can barely make sense of a plant’s awareness … even though I’m thoroughly confident that plants are endowed with it in some manner. When it gets to some form of very diffused awareness that rocks, molecules, atoms, quarks, etc. could be endowed with, I have no idea of what this could possibly mean. Its only when I start thinking of the universe (our uni-logos in the Stoic sense of Logos … so to speak; i.e., our common, singular, objective reality) as adhering to what we term laws of thought—such as that of noncontradiction—that I start feeling that there might be a logical bridge to some form of pan-something, this in relation to the awareness we sentient beings hold. Not anticipating that all this will be agreed with (assuming that it makes good enough sense as written), but wanted to share.

Anyway, thanks for the feedback.

This delineation, however, does a disservice to the form of realism that noAxioms wants to uphold: one that does away with all possible notions of idealism. Because this definition of U depends on awareness in order to hold, it opens doors to idealistic notions. — javra

Wanting to uphold that is well and nice, but so many paths keep coming back to the idealism for which I express my distaste. So in the interest of not caving to my biases, I have to give that consideration.

It could help out to better pinpoint what is intended by the term “existence”. For example, as mentioned in Wikipedia, existence can be classified into the “wide” and the “narrow” sense. In the wide sense of existence, anything that holds any type of being (or presence) can be stated to exist. Figments of the imagination, such as fictional characters, then exist in the wide sense. In the narrow sense, only that which pertains to objective reality (but see the aforementioned for different approaches to what this could imply) can be stated to exist. Harry Potter, then, does not exist in the narrow sense.[/quote]All these are the the same class to me. They are objects, things, representations, relations, whatever, within their universes. None are the universe itself, something that is not a member of some more general structure. So some might classify a relation like velocity to be something that exists, and others else might not. I'm not too concerned with that. What does 'existence' mean to a universe whose full description defines defines that velocity?

Then questions can be posed such as the following: does QM MW exist in the narrow sense, or only in the wide sense?

MW is a strange case, and it seems more a question of if that interpretation is in fact the correct one or not. If that interpretation is correct, then there are certainly other worlds and they are certainly observed, some of them at least. They're really all just other places, all part of one universe actually, and thus fail to be an example of the sort of existence I seek.

Some might say there is no fact of the matter (QM interpretation), but I don't think that fact is beyond investigation. They're attempting to build a quantum computer, which means money is being put behind one interpretation over the other, and that money would be wasted if there was no way to empirically falsify something like hidden-state interpretation.

As a related example, existence could either entail the set of “that which is distinguishable from some background” (this being in line with the literal translation of “standing out”) or the set of “that which holds any sort of presence” (e.g., hypothesizing the Buddhist notion of Nirvana, the state of Nirvana would only exist in the latter sense and not the former). The universe—here presuming it equivalent with everything that exists in the wide sense—can be argued to not exist in the first sense just mentioned: it has no background against which it can be distinguished.

Well, it's that background I'm seeking I think. I'm not so sure about a necessary lack of one.

This conception of the universe, then, can be argued to exist only in the second sense just mentioned. To me this implies that U can exist only as a member of itself. The only way I can find to avoid this conclusion is to grant existence in the wide sense a background of nothingness (also in the wide sense)—but, then, it seems that this would endow nothingness in the wide sense with substantial presence: thereby making nothingness too an aspect of existence in the wide sense. Hence, again leading to the conclusion that set U can exist only as a member of itself.

But I didn't like the second-sense, finding it pretty much the same as the first sense. No, U would not be a member of itself, but it would be a member of something that includes other <need a noun here>'s which also distinguish themselves from whatever background we might identify. I think it presumptuous to select a noun there with the distinction left undefined. I tried 'structure', but not sure if other members that stand out are necessarily structures.