Philosophy Discussion Forums | A Humans-Only Philosophy Club

[GrayArea]

The noun "existence" has more than one meaning: It can be used to refer to an existent, to the totality (sum total) of existents, or to the property of existing. Correspondingly, "Existence exists" means either "The totality (sum total) of existents exists" or "The property of existing exists". The (mereological) sum total of all existents is an existent itself, so it is true in this sense that existence exists.

That's true. But "existence" is still dependent on the existence of particular things --- no particular existents, no "existence."

Whether existence is a (real) property is a contentious issue, so the truth-value of "Existence exists" in this sense depends on whether or not there is such a property as existing.

Yes. Most logicians since Frege and Russell (and even Aristotle) do not consider existence to be a "real" or "actual" property. It functions grammatically as one, however.

Still, the “act” of existing could have come from nothing, because that’s what it means to exist. The opposite of nothing.

[Consul]

No, there is no question-begging, especially as it is clearly incoherent to say "At first there was nothing, and then something suddenly appeared out of/emerged from nothing without any cause or ground". For this presupposes a pre-existing temporal framework, which is something rather than nothing, and also that there being nothing is a possible state of affairs that can obtain before the state of affairs of there being something begins to obtain.

Nope. There is no such presupposition, no framework of any kind. Nothing means nothing --- there is no "pre-existing state of affairs." No time and no space. You're again begging the question, insisting upon cause and effect.

No, my argument applies to the idea of an uncaused appearance of spacetime out of nothing as well!

We can only begin to speak of time, of "before" and "after," once the universe comes into existence.

Right, but no matter whether it is temporally finite or infinite, spacetime was never (at no time) nonexistent; and what was never nonexistent cannot consistently be said to have come, popped, or been brought into existence, since saying so implies falsely that it hasn't always been in existence.

Even if spacetime has a temporal boundary in the past, there is no such possible event as its appearance out of nothing, especially as the very word "event" suggests a change from the absence of spacetime to its presence. But, again, spacetime was never absent (from being), so it cannot consistently be said to have become present by suddenly appearing out of nothing, out of nowhere&nowhen.

Chisholm defines "to begin to exist" as follows:

QUOTE>
"t bounds a prior period of A's existence =df. There is a time t' which is prior to t and such that A exists throughout every period of time between t and t'.

t bounds a subsequent period of A's existence =df. There is a time t' which is subsequent to t and such that A exists throughout every period of time between t and t'.
…
A begins to exist at t =df. t bounds a subsequent but not a prior period of A's existence.

A ceases to exist at t =df. t bounds a prior but not a subsequent period of A's existence."

(Chisholm, Roderick M. "Beginnings and Endings." In Time and Cause: Essays Presented to Richard Taylor, edited by Peter van Inwagen, 17-25. Dordrecht: Reidel, 1980. p. 22)
<QUOTE

Thus defined, a spacetime with a temporal boundary in the past may be said to begin to exist at or after that boundary (depending on whether the boundary of time is part of time or not). However, in this case it's a unilateral and unidirectional temporal boundary, because there is time on its hither side but not on its thither side, where there is nothing at all. Using Chisholm's words, a temporal boundary of spacetime in the past bounds a subsequent but not a prior period of spacetime's existence, but it doesn't bound a prior period of its nonexistence, since there is no time beyond the boundary of spacetime when spacetime could have been nonexistent.

So even if spacetime has a temporal boundary in the past and (in Chisholm's sense of the term) begins to exist at or after it, the beginning of its existence is not preceded by any period of its nonexistence.
Therefore, if spacetime itself has a temporal beginning, it is unlike the temporal beginning of something X in spacetime, where the temporal boundary involved is bilateral and bidirectional, in the sense that it bounds both a subsequent but not a prior period of X's existence and a prior period of X's nonexistence.

Moreover, a temporal beginning of the universe (in Chisholm's sense) is not to be confused with a (caused or uncaused) event describable as the universe's coming or popping into being.

But nothingness qua reified absolute negation, i.e. as a purely negative state of affairs whose essence consists in the absence of everything positive, is impossible in principle.

Per what principle? Cause and effect?

No, "the principle of existential positivity", as one might call it: Absences or lacks of positive things (entia positiva) mustn't be reified and posited as negative things (entia negativa). The absence of positive reality is not to be misconstrued as the presence of a negative reality (called "nothingness").

Even if we talk about uncaused appearances or emergences of things within the existing universe, they would be sheer miracles if they weren't grounded in spontaneous manifestations of pre-existing potentialities inherent in the universe.

Yes, it would be fair to call such events miracles. But we can't rule out miracles on logical grounds, only on pragmatic ones.

Such "miracles" may not be logically impossible, but logical possibility qua mere formal consistency of sentences is only a necessary and no sufficient condition for ontological possibility, for what is possible in reality.
Are there any reasons to believe in the real possibility of "miracles" such as causeless and groundless ex nihilo appearances of things?

Anyway, whenever you try to imagine a (caused or uncaused) sudden appearance of something out of nothing, you cannot help imaginatively employing a spatiotemporal framework—a quiet empty spacetime at least—in which such a "miraculous" event takes place somewhere and somewhen. So if the miraculously appearing thing in question is spacetime itself, you're contradictorily imagining a spacetime appearing in itself.

[GE Morton]

We can only begin to speak of time, of "before" and "after," once the universe comes into existence.

Right, but no matter whether it is temporally finite or infinite, spacetime was never (at no time) nonexistent . . .

That is true if it was "temporally infinite" (which I take to mean, "eternal"). It is also true if it was "temporally finite" --- but only because before its appearance there was no time; hence "no time when it was non-existent." Nothingness has no timeline. We can't speak of a "time when it was non-existent." But that doesn't rule out spontaneous appearance.

. . . and what was never nonexistent cannot consistently be said to have come, popped, or been brought into existence, since saying so implies falsely that it hasn't always been in existence.

Begs the question. "Always" means, "at all times." But "before" (same problem) its appearance there was no time. You need an understanding of "non-existence" that doesn't involve time, since time and space are components of that which spontaneously appeared (per the hypothesis). If the universe is eternal, of course, then time and space have "always existed."

Time and space, like cause and effect, are Kantian categories we accept a priori. But they are not logically necessary, though trying to explain anything without them is very difficult.

Even if spacetime has a temporal boundary in the past . . .

There is no "past" until the appearance of spacetime.

. . . there is no such possible event as its appearance out of nothing, especially as the very word "event" suggests a change from the absence of spacetime to its presence.

Yes, it does suggest a change, but the change is only from nothing to something. We can speak of "after" that change, but not of a "before" it.

But, again, spacetime was never absent (from being) . . .

I can make no sense of this "being," if you are referring to something other than existence. There is no existence prior to the hypothesized event, and no "being" either.

Chisholm defines "to begin to exist" as follows:

. . . .

Thus defined, a spacetime with a temporal boundary in the past may be said to begin to exist at or after that boundary (depending on whether the boundary of time is part of time or not). However, in this case it's a unilateral and unidirectional temporal boundary, because there is time on its hither side but not on its thither side, where there is nothing at all. Using Chisholm's words, a temporal boundary of spacetime in the past bounds a subsequent but not a prior period of spacetime's existence, but it doesn't bound a prior period of its nonexistence, since there is no time beyond the boundary of spacetime when spacetime could have been nonexistent.

Chisolm gets it right. You can't even speak of a "prior period" of its non-existence. As I said above, the concept of non-existence cannot involve assumptions about time.

So even if spacetime has a temporal boundary in the past and (in Chisholm's sense of the term) begins to exist at or after it, the beginning of its existence is not preceded by any period of its nonexistence.
Therefore, if spacetime itself has a temporal beginning, it is unlike the temporal beginning of something X in spacetime, where the temporal boundary involved is bilateral and bidirectional, in the sense that it bounds both a subsequent but not a prior period of X's existence and a prior period of X's nonexistence.

Yes.

Moreover, a temporal beginning of the universe (in Chisholm's sense) is not to be confused with a (caused or uncaused) event describable as the universe's coming or popping into being.

How else would you describe it?

But nothingness qua reified absolute negation, i.e. as a purely negative state of affairs whose essence consists in the absence of everything positive, is impossible in principle.

Per what principle? Cause and effect?

No, "the principle of existential positivity", as one might call it: Absences or lacks of positive things (entia positiva) mustn't be reified and posited as negative things (entia negativa). The absence of positive reality is not to be misconstrued as the presence of a negative reality (called "nothingness").

"Nothingness" does not refer to a "negative reality." You are the one reifying it! It merely refers to the absence of anything (including space and time).

Such "miracles" may not be logically impossible, but logical possibility qua mere formal consistency of sentences is only a necessary and no sufficient condition for ontological possibility, for what is possible in reality.
Are there any reasons to believe in the real possibility of "miracles" such as causeless and groundless ex nihilo appearances of things?

Whatever is logically possible is also ontologically possible, unless we have empirical reasons for ruling out a particular alleged "miracle" (which we usually do, for most of them). Some (or even all) "miracles" may be impossible per some particular ontological theory, of course.

Anyway, whenever you try to imagine a (caused or uncaused) sudden appearance of something out of nothing, you cannot help imaginatively employing a spatiotemporal framework—a quiet empty spacetime at least—in which such a "miraculous" event takes place somewhere and somewhen. So if the miraculously appearing thing in question is spacetime itself, you're contradictorily imagining a spacetime appearing in itself.

Not so, as Chisolm explained. We can speak of a somewhere and somewhen once spacetime appears. It appears at time T0. We just can't speak of a time "prior" to that. But I agree that is is difficult to visualize that event without imagining it occurring on some pre-existing timeline. But that we so imagine such a timeline doesn't render the hypothesis self-contradictory.

I, myself, consider the spontaneous appearance hypothesis less attractive than the only other alternative, the eternal universe. Accepting the former opens a big, nasty can of worms. The latter is conceptually innocuous by comparison.

[Consul]

Right, but no matter whether it is temporally finite or infinite, spacetime was never (at no time) nonexistent . . .

That is true if it was "temporally infinite" (which I take to mean, "eternal"). It is also true if it was "temporally finite" --- but only because before its appearance there was no time; hence "no time when it was non-existent." Nothingness has no timeline. We can't speak of a "time when it was non-existent." But that doesn't rule out spontaneous appearance.

One meaning of "to appear" is "to come forth into view, as from a place or state of concealment, or from a distance; to become visible" (OED). There is still the logical problem that something which was never concealed or invisible cannot consistently be said to come forth into view or to become visible.
Another meaning is "to come into existence", and something which was never nonexistent cannot consistently be said to have come into existence, to have been brought into existence, or to have been caused to exist, because these manners of speaking presuppose incoherently that there was nothing, and then something appeared/came into existence/popped into existence/was brought into existence/was caused to exist.

. . . and what was never nonexistent cannot consistently be said to have come, popped, or been brought into existence, since saying so implies falsely that it hasn't always been in existence.

Begs the question. "Always" means, "at all times." But "before" (same problem) its appearance there was no time. You need an understanding of "non-existence" that doesn't involve time, since time and space are components of that which spontaneously appeared (per the hypothesis). If the universe is eternal, of course, then time and space have "always existed."

Any transition from nonexistence to existence presupposes time, i.e. a prior period of nonexistence and a subsequent period of existence; and if there is no such temporal transition from nonbeing to being, then there is no such event at the boundary of time in the past (if there is any) as an appearing, a coming or popping into being (with or without a cause).

Even if spacetime has a temporal boundary in the past . . .

There is no "past" until the appearance of spacetime.

Of course, there is no pre-time time; and this is why speaking of an "appearance" or "emergence" of spacetime at its temporal boundary in the past (if there is any such boundary) makes no sense.

. . . there is no such possible event as its appearance out of nothing, especially as the very word "event" suggests a change from the absence of spacetime to its presence.

Yes, it does suggest a change, but the change is only from nothing to something. We can speak of "after" that change, but not of a "before" it.

But then there is no change at all, because there is no change unless there is a pre-change state of being and a post-change state of being. A "change from (absolutely) nothing to something" is not a change at all, since there couldn't have been any pre-change state of (absolute) nonbeing. If spacetime has a temporal boundary in the finite past, then no change takes place there.

Moreover, a temporal beginning of the universe (in Chisholm's sense) is not to be confused with a (caused or uncaused) event describable as the universe's coming or popping into being.

How else would you describe it?

If spacetime has a temporal beginning, it's like the spatial beginning of a ruler. You don't say a ruler comes or pops into being at its left beginning, do you?

We can speak of a somewhere and somewhen once spacetime appears. It appears at time T0. We just can't speak of a time "prior" to that. But I agree that is is difficult to visualize that event without imagining it occurring on some pre-existing timeline. But that we so imagine such a timeline doesn't render the hypothesis self-contradictory.

I, myself, consider the spontaneous appearance hypothesis less attractive than the only other alternative, the eternal universe. Accepting the former opens a big, nasty can of worms. The latter is conceptually innocuous by comparison.

My point is that nothing—no (caused or uncaused) appearance or emergence ex nihilo—takes place at a temporal boundary T0 of spacetime. T0 is a boundary in one direction only, viz. the future, since it doesn't bound any prior period during which spacetime doesn't yet exist. Therefore, nothing changes at T0! The situation <T0 isn't different from the situation >T0, since there is no situation <T0.

"Eternal" can mean "existing at all times" and "having infinite duration". MEST (the matter-energy-space-time world) is doubtless eternal in the former sense, but we don't know if it's also eternal in the latter sense, i.e. whether it has a temporal boundary in the past or/and the future.

[Sculptor1]

1. Nothingness was the original state of the universe.
2. The current state of the universe is a state of something.
3. Therefore something can come from nothing.

Impeccable logic

[Consul]

… Nothingness has no timeline. We can't speak of a "time when it was non-existent." But that doesn't rule out spontaneous appearance.

"Might something have spontaneously popped into existence? Spontaneity requires something to be spontaneous. Even the idea that God could create material bodies ex nihilo starts with God."

(Heil, John. "Contingency." In The Puzzle of Existence: Why Is There Something Rather Than Nothing?, edited by Tyron Goldschmidt, 167-181. New York: Routledge, 2013. p. 180)

[Consul]

QUOTE>
"The Nothing Option

…When you ask, ‘Why is there something rather than nothing?’ what are the envisioned options: something and nothing? Well, there is the specific something we inhabit, the universe as a whole. So, why, you might ask, does the universe exist, rather than nothing at all?

Now the hard part. What exactly is nothing at all? What would nothing be? In what sense is nothing an alternative to something?

In this context it would be a cheat to imagine God deciding whether to create something, a universe. God is a something. It is not as though, prior to creation, you have God plus nothing. You just have God. Now, take God out of the picture and try to imagine the nothing option. This is none too easy.

Some will see no particular difficulty: nothing is just nonbeing, the absence of being; what’s the big deal? If you think that is the end of the story, I doubt that you will be much moved by what I have to say here. I remain convinced that our grasp of the idea of nothing is tenuous at best. You might try to get at nothing by imagining a universe with only a handful of objects, electrons, say, then subtracting these one at a time until no electron remains. But the electrons are located somewhere in space. Their subtraction yields, not nothing, but empty space, a space empty of objects.

My guess is that most of us, in imagining nothingness, are imagining empty space. But a space, empty or not, is a something. It has, let us suppose, three dimensions; its regions are distinct. Physics tells us that empty space is substance-like; empty space has energy; empty space is ‘unstable’, forever finding ways to be nonempty. Medievals endowed ‘void space’ with powers. How a body would behave in the void was a matter of controversy, but some medievals assumed that the void was not homogeneous. God could create a void by miraculously annihilating matter occupying the region between the earth and the lunar sphere. But the void would retain local characteristics of fire, air, water, and earth. Bodies moving about in the void would behave differently depending on where in the void they happened to be.

It is hard not to think of the void as extended spatially, hard not to think of it as a three-dimensional container unpopulated by bodies, hard not to think of the void as empty space. The void, so conceived, is a something, not a nothing. It is much harder to think of the absence of everything including the void. Start with a conception of a universe consisting solely of empty space, the empty universe. Now subtract the empty space. Is this something God could do? If space is a substance or is substance-like, why not? But now God, a manifest something, is back in the picture.

I do not mean to suggest that space itself could not have arisen from something else during the Big Bang. I take this to be a serious option. But a precursor of the Big Bang is a something.

It is much harder to understand the nothing option than you might have thought. Everyday nothings, holes, for instance, require somethings to exist. A pothole in the highway requires the highway; an empty ballroom requires a ballroom. I find it hard not to think that the question ‘Why is there anything?’ or ‘Why is there something rather than nothing?’ makes sense only when the nothing in question is really a something: empty space, the void, the precursor to the Big Bang. Thus understood, the question admits of an answer, although perhaps one we are barred from discovering owing to a lack of access to the pre–Big-Bang state of play. If, in contrast, nothing is understood as the absolute absence of being, the question cannot so much as be addressed."

(Heil, John. "Contingency." In The Puzzle of Existence: Why Is There Something Rather Than Nothing?, edited by Tyron Goldschmidt, 167-181. New York: Routledge, 2013. pp. 174-6)
<QUOTE

"Now the hard part. What exactly is nothing at all? What would nothing be? In what sense is nothing an alternative to something?" – J. Heil

Nothing(ness) would be nothing at all, so it's no ontological alternative to being; and nonbeing as an alleged non-ontological alternative to being is no alternative at all.

"There is just no alternative to being."

(Rundle, Bede. Why there is Something rather than Nothing. Oxford: Oxford University Press, 2004. p. 112)

[GE Morton]

QUOTE>
"The Nothing Option

…When you ask, ‘Why is there something rather than nothing?’ what are the envisioned options: something and nothing? Well, there is the specific something we inhabit, the universe as a whole. So, why, you might ask, does the universe exist, rather than nothing at all?

Now the hard part. What exactly is nothing at all? What would nothing be? In what sense is nothing an alternative to something?

In this context it would be a cheat to imagine God deciding whether to create something, a universe. God is a something. It is not as though, prior to creation, you have God plus nothing. You just have God. Now, take God out of the picture and try to imagine the nothing option. This is none too easy.

Some will see no particular difficulty: nothing is just nonbeing, the absence of being; what’s the big deal? If you think that is the end of the story, I doubt that you will be much moved by what I have to say here. I remain convinced that our grasp of the idea of nothing is tenuous at best. You might try to get at nothing by imagining a universe with only a handful of objects, electrons, say, then subtracting these one at a time until no electron remains. But the electrons are located somewhere in space. Their subtraction yields, not nothing, but empty space, a space empty of objects.[italics added]

Nope. There is no space without some objects which occupy it. "Space" can only be defined, observed, or measured with reference to some objects (broadly construed). We can speak of empty spaces with some specified boundaries ("Half of the warehouse was filled with hay bales. The rest was empty space"). Or spaces empty of something-or-other ("The glass is empty" (of water, but not of air)). But there is no space empty of everything; if there is nothing, there is no space, either. Rundle seems to be resurrecting Newton's "absolute" space.

=Rundle]My guess is that most of us, in imagining nothingness, are imagining empty space. But a space, empty or not, is a something. It has, let us suppose, three dimensions; its regions are distinct.

Oh, we can imagine an empty space with three dimensions, or 9, or 12. Or one or two ("Flatland"). But unless these spaces contained something, we'd have no means of deciding how many dimensions they had. Imagined states of affairs are not "real" states of affairs. And we can also imagine nothingness -- an absence of everything, including space and time. That may not be real either, but it can't be ruled out on logical grounds alone.

It is hard not to think of the void as extended spatially, hard not to think of it as a three-dimensional container unpopulated by bodies, hard not to think of the void as empty space. The void, so conceived, is a something, not a nothing. It is much harder to think of the absence of everything including the void.

Yes, it is.

It is much harder to understand the nothing option than you might have thought. Everyday nothings, holes, for instance, require somethings to exist. A pothole in the highway requires the highway; an empty ballroom requires a ballroom. I find it hard not to think that the question ‘Why is there anything?’ or ‘Why is there something rather than nothing?’ makes sense only when the nothing in question is really a something: empty space, the void, the precursor to the Big Bang. Thus understood, the question admits of an answer, although perhaps one we are barred from discovering owing to a lack of access to the pre–Big-Bang state of play. If, in contrast, nothing is understood as the absolute absence of being, the question cannot so much as be addressed."

I agree. That would include dismissing it on logical grounds.

Nothing(ness) would be nothing at all, so it's no ontological alternative to being . . .

Of course it is. ~P is always an alternative to P.

[GE Morton]

Another meaning is "to come into existence", and something which was never nonexistent cannot consistently be said to have come into existence, to have been brought into existence, or to have been caused to exist, because these manners of speaking presuppose incoherently that there was nothing, and then something appeared/came into existence/popped into existence/was brought into existence/was caused to exist.

We covered this. A claim that something appeared from nothing may be counterintuitive, theoretically impossible (depending upon the theory), and intellectually disturbing, but it is not incoherent. "Incoherent" means:

1a: lacking normal clarity or intelligibility in speech or thought
b:lacking orderly continuity, arrangement, or relevance : INCONSISTENT

https://www.merriam-webster.com/dictionary/incoherent

The claim is perfectly clear and intelligible, however incomprehensible what it asserts. It would be, as mentioned before, a "miracle." Claims of miracles, while incompatible with a scientific weltanschauung, are quite intelligible.

Any transition from nonexistence to existence presupposes time, i.e. a prior period of nonexistence and a subsequent period of existence; and if there is no such temporal transition from nonbeing to being, then there is no such event at the boundary of time in the past (if there is any) as an appearing, a coming or popping into being (with or without a cause).

You're still begging the question. There is no logical reason why the transformation could not be instantaneous. There would be no "period of non-existence" before that event, since, by hypothesis, there is no time "before" it.

Yes, it does suggest a change, but the change is only from nothing to something. We can speak of "after" that change, but not of a "before" it.

But then there is no change at all, because there is no change unless there is a pre-change state of being and a post-change state of being. A "change from (absolutely) nothing to something" is not a change at all, since there couldn't have been any pre-change state of (absolute) nonbeing.

"State of affairs" may be less prejudicial. But your last statement there is dogmatic. Why not?

If spacetime has a temporal beginning, it's like the spatial beginning of a ruler. You don't say a ruler comes or pops into being at its left beginning, do you?

Bad analogy. What one may say of things within spacetime don't --- indeed, can't --- apply to spacetime itself. That would raise Gödel-like problems.

[EricPH]

1. Nothingness was the original state of the universe.
2. The current state of the universe is a state of something.
3. Therefore something can come from nothing.

Impeccable logic

Impeccable logic that requires magic. The only other possibility seems to be; something had no beginning.

Both logical explanations seem to defy logic as we know.

[GE Morton]

1. Nothingness was the original state of the universe.
2. The current state of the universe is a state of something.
3. Therefore something can come from nothing.

Impeccable logic

Impeccable logic that requires magic. The only other possibility seems to be; something had no beginning.

Both logical explanations seem to defy logic as we know.

They defy "common sense" and intuitions, but not logic.

[Sculptor1]

1. Nothingness was the original state of the universe.
2. The current state of the universe is a state of something.
3. Therefore something can come from nothing.

Impeccable logic

Impeccable logic that requires magic...

No the logic does not require any magic.
Like all claims made to logical process it is always the assumptions and premises that are magical or faulty.
This is why the entire thread is an exercise in textual masturbation.

The only other possibility seems to be; something had no beginning.

Both logical explanations seem to defy logic as we know.

No. a logical explanation does not defy logis.
A logical explanation might be devoid of empirical or evidential support, yes.
You clearly feel upset at that idea that nothingness was the original state of the universe; or the claim that something comes from nothing.
Surely that unease might be justified. However your feeling has nothing to do with logic.
I would imagine that you are relying on an inductive reflection or uniformitarianism that nothing comes from nothing.
But you cannot really justify that position. You can assert it, though.
You might want to reflect the disquiet that others have with the idea of infinity, or the fact that all our cosmological evidence seem to indication a point of origin.
Ho hum!
Neither of these feelings are about logic.

[Consul]

Nope. There is no space without some objects which occupy it. "Space" can only be defined, observed, or measured with reference to some objects (broadly construed). We can speak of empty spaces with some specified boundaries ("Half of the warehouse was filled with hay bales. The rest was empty space"). Or spaces empty of something-or-other ("The glass is empty" (of water, but not of air)). But there is no space empty of everything; if there is nothing, there is no space, either. Rundle seems to be resurrecting Newton's "absolute" space.

According to relationalism about space, it is a web of spatial relations between physical objects; and, of course, if that's what space is, then removing all physical objects means removing space, because relations cannot exist without any relata.
Well, some ontologists think otherwise, believing in relataless relations; and a spatial relationalist who does so can regard empty space as a web of spatial relations that aren't instantiated by any physical objects. But for a spatial relationist who disbelieves in objectless spatial relations there is no difference between empty space and the absence of space: If all physical objects are removed, all spatial relations are thereby removed too—and thus relational space disappears altogether.

According to substantialism about space, it is a substantial entity in its own right that can be empty in the sense of being unoccupied by any physical objects.

"My guess is that most of us, in imagining nothingness, are imagining empty space. But a space, empty or not, is a something. It has, let us suppose, three dimensions; its regions are distinct." – John Heil

Oh, we can imagine an empty space with three dimensions, or 9, or 12. Or one or two ("Flatland"). But unless these spaces contained something, we'd have no means of deciding how many dimensions they had. Imagined states of affairs are not "real" states of affairs. And we can also imagine nothingness -- an absence of everything, including space and time. That may not be real either, but it can't be ruled out on logical grounds alone.

Objects in 3D space can move horizontally (left and right), vertically (up and down), and forward and backward; so 3D space is defined in terms of the possible directions of motion therein, which doesn't require that 3D space is actually occupied by objects moving therein.

If imagining means visualizing, then I cannot imagine any >3D spaces. Visualizing an empty 3D space (from the substantialist perspective) is like visualizing a pure solid glass cube.
If imagining means conceiving by means of words rather than visual images, then we can imagine >3D spaces.

I cannot visually imagine nothingness, if doing so is supposed to be different from not visually imagining anything. When I close my eyes, I can imagine a white empty canvas, a dark empty expanse, and a volume of pure transparent stuff (such as glass); but I cannot imaginatively remove all of that and end up with imagining nothingness, because nothingness qua absence of everything is (visually) unimaginable. It is only conceivable in the sense that we do have the concept of nothingness (the noun "nothingness"). However:

QUOTE>
"First, note that the word ‘nothing’ can be used as a quantifier, but it also has a perfectly good use as a noun phrase, meaning nothingness. (Hegel and Heidegger wrote about nothing, but said quite different things about it.) In what follows, to avoid any confusion, when I wish to use ‘nothing’ as a noun phrase I will boldface it, thus: nothing.
Nothing is the absence of all things. It is, as it were, what remains after everything has been removed; and by ‘everything’, here, I mean absolutely everything, all things.
It follows that nothing is ineffable. To talk about something requires one to predicate something of it. One can predicate nothing of nothing simply because there is nothing there of which to predicate it. One might also put the point this way. To predicate P of something, a, requires a to be an object. (I do not say existent object.) The very syntax Pa tells you this. But nothing is not an object: it is the result of removing all objects.
Of course, we are in paradoxical territory here. Nothing is an object (as well). After all, one can refer to it by the name ‘nothing’. Consequently, it is effable, as well."
(pp. 17-8)

"Nothing is an object. We can, for example, think about it. … [N]othing is a contradictory object. Since it is an object, it is something. But it is the absence of all things too; so nothing is nothing. Everything is the mereological sum of the universal set. Nothing is the mereological sum of the empty set. But there is nothing in the empty set, so nothing is absolute absence: the absence of all objects, all presences. It is no thing, no object."
(p. 56)

(Priest, Graham. "Nothingness and the Ground of Reality: Heidegger and Nishida." In Non-Being: New Essays on the Metaphysics of Non-Existence, edited by Sara Bernstein and Tyron Goldschmidt, 17-33. Oxford: Oxford University Press, 2021.)
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"It is much harder to understand the nothing option than you might have thought. Everyday nothings, holes, for instance, require somethings to exist. A pothole in the highway requires the highway; an empty ballroom requires a ballroom. I find it hard not to think that the question ‘Why is there anything?’ or ‘Why is there something rather than nothing?’ makes sense only when the nothing in question is really a something: empty space, the void, the precursor to the Big Bang. Thus understood, the question admits of an answer, although perhaps one we are barred from discovering owing to a lack of access to the pre–Big-Bang state of play. If, in contrast, nothing is understood as the absolute absence of being, the question cannot so much as be addressed." – John Heil

I agree. That would include dismissing it on logical grounds.

Heil's point is that nonbeing or absence depends on being or presence, in which case absolute nonbeing or absence is impossible. For example, for all holes there is some hole-surround; and if the latter is removed, the former is thereby removed too.

Nothing(ness) would be nothing at all, so it's no ontological alternative to being . . .

Of course it is. ~P is always an alternative to P.

There is no possible real (non-nominal/non-verbal) alternative to what is necessarily true or the case: If it is necessary that p, then it is impossible that not-p!

If being must be, then nonbeing cannot be, in which case nonbeing is no possible alternative to being. And being must be, precisely because nonbeing cannot be due to "being nonbeing" being a self-contradictory phrase.

[Consul]

We covered this. A claim that something appeared from nothing may be counterintuitive, theoretically impossible (depending upon the theory), and intellectually disturbing, but it is not incoherent. "Incoherent" means:

1a: lacking normal clarity or intelligibility in speech or thought
b:lacking orderly continuity, arrangement, or relevance : INCONSISTENT

https://www.merriam-webster.com/dictionary/incoherent

The claim is perfectly clear and intelligible, however incomprehensible what it asserts. It would be, as mentioned before, a "miracle." Claims of miracles, while incompatible with a scientific weltanschauung, are quite intelligible.

I don't think so. The OED defines "miracle" as "a marvellous event occurring within human experience, which cannot have been brought about by human power or by the operation of any natural agency, and must therefore be ascribed to the special intervention of the Deity or of some supernatural being," and I fail to see what is "quite intelligible" about such miracles?

Anyway, we need to distinguish between the (question of the) possibility of a caused or uncaused ex nihilo appearance or emergence of something within MEST and the (question of the) possibility of a caused or uncaused ex nihilo appearance or emergence of MEST itself.

As for the former, for instance, is it possible for a second moon of the Earth to causelessly materialize out of nothing, i.e. not out of any pre-existing matter or energy? It's not physically possible, but it is logically possible. However, its being logically possible doesn't render such an event intelligible and explicable, especially as it's physically impossible.

As for the latter, there is still the logical incoherence of speaking of an appearance or emergence of MEST from nothing, which presupposes incoherently that there is a bilateral temporal boundary bounding both a prior period of MEST's nonexistence and a subsequent period of MEST's existence. It's the lack of any prior period of MEST's nonexistence and the lack of any existence prior to MEST that prevents us from coherently conceiving or imagining its ex nihilo appearance or emergence (as a kind of event or process). This situation is logically unlike the former situation where a new celestial body appears out of nothing (i.e. not out of any pre-existent matter/energy) but within pre-existent MEST, such that we have an event with a spatiotemporal location. The popping into being of a being within being is unlike the popping into being of being.

Any transition from nonexistence to existence presupposes time, i.e. a prior period of nonexistence and a subsequent period of existence; and if there is no such temporal transition from nonbeing to being, then there is no such event at the boundary of time in the past (if there is any) as an appearing, a coming or popping into being (with or without a cause).

You're still begging the question. There is no logical reason why the transformation could not be instantaneous. There would be no "period of non-existence" before that event, since, by hypothesis, there is no time "before" it.

Yes, but then the question is still whether it makes any sense to speak of an atemporal appearance or emergence of existence in an ontological "vacuum".

There is no possible transformation unless there is some pre-existing transformable stuff. And no transformation or transition from one state to another can take place instantaneously, because nothing can change "during" an instant with a duration of 0s—the reason being that we would then have both p and ~p at one and the same instant, which is logically impossible.

If spacetime has a temporal beginning, it's like the spatial beginning of a ruler. You don't say a ruler comes or pops into being at its left beginning, do you?

Bad analogy. What one may say of things within spacetime don't --- indeed, can't --- apply to spacetime itself. That would raise Gödel-like problems.

I don't know what Gödel's theorems have to do with this; but yes, as I already mentioned above, ex nihilo appearances or emergences of things in spacetime are to be distinguished from the ex nihilo appearance or emergence of spacetime itself. As for the latter, my argument against its coherent conceivability goes as follows: An event such as an appearance or emergence of something necessarily takes place within a spacetime context. However, there is no pre-spacetime spacetime context, there being neither a space where the ex nihilo appearance or emergence of spacetime could have occurred nor a time when it could have occurred. Therefore, if spacetime has a temporal boundary in the past, there is no event there which can be coherently described as an ex nihilo appearance or emergence of spacetime.

[Consul]

Even if spacetime has a temporal boundary in the past, there is no such possible event as its appearance out of nothing, especially as the very word "event" suggests a change from the absence of spacetime to its presence. But, again, spacetime was never absent (from being), so it cannot consistently be said to have become present by suddenly appearing out of nothing, out of nowhere&nowhen.

Chisholm defines "to begin to exist" as follows:

QUOTE>
"t bounds a prior period of A's existence =df. There is a time t' which is prior to t and such that A exists throughout every period of time between t and t'.

t bounds a subsequent period of A's existence =df. There is a time t' which is subsequent to t and such that A exists throughout every period of time between t and t'.
…
A begins to exist at t =df. t bounds a subsequent but not a prior period of A's existence.

A ceases to exist at t =df. t bounds a prior but not a subsequent period of A's existence."

(Chisholm, Roderick M. "Beginnings and Endings." In Time and Cause: Essays Presented to Richard Taylor, edited by Peter van Inwagen, 17-25. Dordrecht: Reidel, 1980. p. 22)
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Thus defined, a spacetime with a temporal boundary in the past may be said to begin to exist at or after that boundary (depending on whether the boundary of time is part of time or not). However, in this case it's a unilateral and unidirectional temporal boundary, because there is time on its hither side but not on its thither side, where there is nothing at all. Using Chisholm's words, a temporal boundary of spacetime in the past bounds a subsequent but not a prior period of spacetime's existence, but it doesn't bound a prior period of its nonexistence, since there is no time beyond the boundary of spacetime when spacetime could have been nonexistent.

So even if spacetime has a temporal boundary in the past and (in Chisholm's sense of the term) begins to exist at or after it, the beginning of its existence is not preceded by any period of its nonexistence.
Therefore, if spacetime itself has a temporal beginning, it is unlike the temporal beginning of something X in spacetime, where the temporal boundary involved is bilateral and bidirectional, in the sense that it bounds both a subsequent but not a prior period of X's existence and a prior period of X's nonexistence.

Moreover, a temporal beginning of the universe (in Chisholm's sense) is not to be confused with a (caused or uncaused) event describable as the universe's coming or popping into being.

Here's David Oderberg's definition of "to begin to exist":

QUOTE>
"(B2S): x begins to exist during a closed interval [t_0, t_n] or an open interval ]t_0, t_n]
=df
(i) x exists at every t_i in the closed interval [t_0, t_n] and there is no t_j < [t_0, t_n] at which x exists; or
(ii) x exists at every t_i in the open interval ]t_0, t_n] and x does not exist at t_0 and there is no t_j < ]t_0, t_n] at which x exists."

(Oderberg, David S. "The Beginning of Existence." International Philosophical Quaterly 43/2 (2003): 145-157. p. 150)
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The sentence "There is no t_j < [(])t_0, t_n] at which x exists" is true if there are times t_j < [(])t_0, t_n] at which x doesn't exist, and it is true if there are no times t_j < [(])t_0, t_n] at which x could have existed.

If what is said to begin to exist is time itself, then there certainly couldn't have been any times at which time doesn't exist.

Here's William Craig's definition of "to begin to exist":

QUOTE>
"…[Adolf] Grünbaum appears to assert that it belongs analytically to the concept of some entity x's beginning to exist that there were instants of time prior to x's beginning at which x did not exist. Perhaps we can express this by stating

'x begins to exist' =def 'X exists at time t and there are times immediately prior to t at which x does not exist.'

But it seems very strange that x's beginning to exist at t entails the existence of temporal instants prior to t. Imagine that the temporal instants prior to a performance of Beethoven's Fifth Symphony were non-existent. Should we say that the symphony concert then fails to have a beginning, even though it is precisely the same concert as that which is contingently preceded by temporal moments? Griinbaum gives no argument for this claim. The fact that x begins to exist ought to leave the question of existents prior to x altogether open; that is,

'x begins to exist' =def 'x exists at t and there is no time immediately prior to t at which x exists.'

So understood, any thing existing at the first moment of time begins to exist as surely as a temporally embedded concert begins to exist. The ineptness of Grünbaum's definition is evident in that it entails that a beginning of time itself is analytically impossible, which is surely wrong. To say that time began to exist is not to assert the self-contradiction that prior to t = 0 there were times at which time did not exist, but to claim, as Quentin Smith points out, that (i) there is a finite interval of time such that every other interval of the same length is later than that interval and (ii) prior to any interval of a given finite length there is at most a finite number of intervals of the same length (Smith [1985: "On the Beginning of Time "], p. 579).

Grünbaum trades on certain infelicities of expression, for example, the question as to what happened before the Big Bang, in order to object to seeking a cause of that event. But such expressions may be regarded as a façon de parler; it is philosophically unobjectionable to conceive of God as causally, if not temporally, prior to the Big Bang. God's act of creation may be regarded as simultaneous with the origin of the universe. Nor do I see any reason for Grünbaum's objection to our saying that the universe came into being or that its origin was 'sudden'. A physical thing comes into being if it exists at t and there are no moments immediately prior to t at which it exists; an event is sudden if it happens without antecedent warning. Both these expressions seem entirely appropriate with regard to the universe's origin."

(Craig, William Lane. "The Origin and Creation of the Universe: A Reply to Adolf Grünbaum." The British Journal for the Philosophy of Science 43/2 (1992): 233–240. pp. 237-8)
<QUOTE

Craig's definition corresponds to Oderberg's insofar as the sentence "There is no time immediately prior to t at which x exists" is true if there are times immediately prior to t at which x doesn't exist, and it is true if there are no times immediately prior to t at which x could have existed.

Footnote: If time is continuous, then Craig's definition is inadequate, because then there are no times immediately prior to t, with there being infinitely many times (time-points) between any two times t and t*.

I doubt that "it is philosophically unobjectionable to conceive of God as causally, if not temporally, prior to the Big Bang. God's act of creation may be regarded as simultaneous with the origin of the universe." One reason is that God's intention or decision to create a spatiotemporal universe couldn't have been simultaneous with the Big Bang. Generally, intentions and decisions to act are temporally prior to the actions.
(Note that intentions to act are different from intentions in action, the latter of which are simultaneous with the actions!)

Here's Quentin Smith's definition of the beginning of time:

QUOTE>
"In defending the idea that a beginning of time can be coherently conceived the first thing to establish is that the following objection is invalid: 'Everything that begins does so in time; therefore time itself cannot have a beginning.' This argument relies on the premise that 'to begin' means (1) there is an earlier time at which the thing or state is not, and (2) there is a later time at which the thing or state is; this premise justifies the conclusion that it is impossible for time to begin since that would involve a time earlier than time. The response to this objection is that 'to begin' has different senses when applied to time and things and states in time. As applied to time, it means:

1. There is an interval of time such that every other interval of the same length is later than that interval.
2. Prior to any interval of a given length, there is at most a finite number of intervals of the same length.

Note that-this analysis of a beginning of time concerns intervals 'of the same length'; if this qualifying phrase is not added, then the analysis would be invalid for a dense time. If time is dense and began, then for each interval of time there is another interval of a shorter length that is a part of that interval and which com-pletely elapses before the interval of which it is a part completely elapses. Before the first hour completely elapses, the first minute does so, and before the first minute, the first second, and so on ad infinitum. This entails that there is no 'first moment' of time in the sense of an interval that precedes every other interval, but there is a 'first moment' in the sense that there is a first interval of each length of time: there is a first hour, a first minute, etc.

But if time is discrete there is a 'first moment' in both senses: there is one interval (of the shortest length) that is earlier than every other interval, and there is also an earliest interval of each length."

(Smith, Quentin. "On the Beginning of Time." Nous 19/4 (1985): 579–584. pp. 579-80)
<QUOTE

I concede that these are definitions of "to begin to exist" which can be consistently applied to time itself. However, there is still the question of what exactly "to begin" means here. What exactly does it mean to say that time (or space) has a beginning? One definition of "beginning" in the OED is "the earliest or first part of any space or time"; and if to say that the spatiotemporal universe has a temporal beginning is to say that it has a temporal boundary in the past which is its earliest or first temporal part, then I can happily accept that. However, I don't regard "Time has a temporal boundary in the past, and thus an earliest or first temporal part" and "Time appeared/emerged out of nothing at its temporal boundary" as synonymous.