Thursday, June 13, 2019

Is eternalism compatible with the actualization of potentiality?

Every so often, someone claims to me that there is a difficulty in reconciling the Aristotelian idea of the actualization of potential with eternalism, the view that past, present and future are equally real. I am puzzled by this question, because I can’t see the difficulty. On the contrary, there is a tension between presentism, the view that only present things exist, and this Aristotelian thesis:

  1. Some present events are the actualization of a no-longer present potentiality.

  2. A non-existent thing is not actualized.

  3. Therefore, some no-longer present potentialities exist.

  4. Therefore, something that is no longer present exists.

  5. Therefore, presentism is false.

One might say: Yes, the potentiality doesn’t exist, but it did exist, and it was actualized. But then:

  1. Some present potentialities are actualized in not yet present events.

  2. A non-existent thing does not actualize anything.

  3. So, there exist some not yet present things.

  4. So, presentism is false.

Of course, this is the old problem of transtemporal relations for presentism as applied to the actualization relation.

So, what about the question whether eternalists can have actualization of potentials? Here may be the problem. On eternalism plus Aristotelianism, it seems that the past unactualized potential exists even though it is now actualized. This seems to be a contradiction: how can an unactualized potential be actualized?

A first answer is that a potential is actualized at a time t provided that its actualization exists at t. Thus, the potential is unactualized at t1 but actualized at a later time t2, because its actualization exists at t2 but not at t1. But, the objector can continue, by eternalism at t1 isn’t it the case that the actualization exists? Yes: but the eternalist distinguishes:

  1. It is true at t1 that B exists.

  2. B exists at t1.

Claim (11), for spatiotemporal objects, means something like this: the three-dimensional spacetime hypersurface corresponding to t = t1 intersects B. Claim (10) means that B exists simpliciter, somewhere in spacetime (assuming it’s a spatiotemporal object). There is no contradiction in saying that the actualization doesn’t exist at t1, even though it is true at t1 that it exists simpliciter.

The second answer is that Aristotelianism does not need actualizations of unactualized potentials. Causation is the actualization of a potential. But Aristotle and Aquinas both believed in the possibility of simultaneous causation. In simultaneous causation, an event B is the actualization of a simultaneous potential A. At the time of the simultaneous causation, nobody, whether presentist or eternalist, can say that B is the actualization of unactualized potential, since then the potential would be actualized and unactualized at the same time. Thus, one can have causation, and actualization of potential, where the potential and the actualization are simultaneously real, and hence where the actualization is not of an unactualized potential. The eternalist could—but does not have to—say that transtemporal cases are like this, too: they are actualizations of a potential, but not of an unactualized potential.


Red said...

"A first answer is that a potential is actualized at a time t provided that its actualization exists at t. Thus, the potential is unactualized at t1 but actualized at a later time t2, because its actualization exists at t2 but not at t1. But, the objector can continue, by eternalism at t1 isn’t it the case that the actualization exists? Yes: but the eternalist distinguishes:

It is true at t1 that B exists.

B exists at t1."

This seems implausible because it doesn't seem like existence or actuality can be indexed like that. It seems to me that there is actually no distinction between claims like 10 and 11. The real distinction given eternalism is between a things existence and its location not existence simpliciter and existence at and this seems clear from your explanation of 11, the correspondence doesn't have anything to do with existence but the location.

And about the point about simultaneous causation, it is very interesting case. I think more needs to be said about why actualizations of unactualized potentials is not needed. The problem is I think that notion of potentiality is not a clear one, It needs a further analysis, The presentists framework seems to me to be the best way to analyse it but it isn't perfect due to these cases.

Matt H. said...

Hi Red, maybe I'm not following your objection properly, but wouldn't a distinction between existence & location be the same thing to an eternalist as existence & existence at t? In the 4d block that includes all of history wouldn't an eternalist say a thing exists if it is found somewhere within the block, but that it doesn't have existence at every location (time t1,t2,etc.) If a thing is not present at t1, but it is at t2 then at t1 you would say "it exists, but not here (e.g. at this time)" and at time t2 you would say "it exists, and it is here."

Red said...

Hello Matt H.

Maybe you are right. That is how I tend to think of this issue but I could be wrong about the language here. But the main problem again is that notion of potentiality isn't very clear although I think I accept it because it is plausible,it is much less clear on Eternalism.
If a thing is actual at a certain time but simply not-actual at other times( in the sense that actualization isn't located at those times) in what sense can it be really said to be potential. We are simply talking about it being actual here and it not being actual there.

I guess this is one of the reasons I find presentism more plausible, there is a better story to be told about potentiality there although that has problems too.

Michael Gonzalez said...

Matt H,

I'm sorry, but I think "it exists, but doesn't 'have existence' at such-and-such times" is completely meaningless, and shows the conceptual muddle of eternalism. Imagine a 6D block, instead of a 4D one; and assign 3 of them the special status of being "time", instead of just one. You could even go along with Tim Maudlin and make those 3 "inherently directed" in the new topological framework that he's developing. It is the most obvious thing in the world that every part of this block exists concurrently, with some parts being "over there" and some "over here". The only way time (the real "time" that any normal person means by the word "time") enters into things is if I ask "has the block always been shaped that way, or can it change?". The eternalist has to think of this as a non-question, or a misunderstanding; but it is actually as legitimate as that sort of question always is. After all, Maudlin himself (who accepts the "block" view), when discussing time travel, says that the closed time-like curves have to "always have existed". What does that mean? What does it mean to say that the 4d (or 6d or 100d) block "exists", but I'm just not allowed to ask "has it always existed?"?

In other words, can my 4d (or 6d or 100d) shape change, or is it static (being "different at different times" only in the same sense that any shape is different at different locations)?

Alexander R Pruss said...

We are certainly happy to distinguish "exists" from "exists in" in the case of spatial location. "Tigers exist in India but not in Africa" is a fine sentence of English.

Michael Gonzalez said...

Sure, but the difference between "exists" and "existed" is different than the difference between "exists in", isn't it? "Existed" means "no longer exists, but used to". I think it would be perfectly reasonable to ask of any given 4 (or more) dimensional block "could this or that piece cease to exist if God wanted it to?" Or "could the 4d shape of this thing be altered by God?"

Alexander R Pruss said...

"No longer" might just mean "in this time".

Michael Gonzalez said...

"No longer" might just mean "in this time".

I'm genuinely curious: Do you not feel that that is sort of a trick with words? I mean, why were atheist thinkers so annoyed by the discovery that the equations of General Relativity can imply a beginning to the Universe? After all, that would just be a front edge to a Universe that is no less eternally existent than the one without a front edge. It's just a matter of its topology, nothing metaphysically interesting about that (any more than discovering it has a spatial edge should be particularly annoying to an atheist)....

Alexander R Pruss said...

No, it doesn't seem to me to be a trick with words.

I think people were annoyed by the front edge as it made it obvious that the universe is not self-explanatory in the Humean infinite-regress way.

Michael Gonzalez said...

My intuitions must just be all wrong, but I don't see why the 4(or more)d shape of the Universe has anything to do with regress. Lol. I mean, if the block just exists, changelessly and without coming into being from non-being, what difference does it make if any of the coordinates have edges?

Alexander R Pruss said...

Well, the lower edge has no cause. That seems to make a difference. It's not about shape but about the causal connections.

Alexander R Pruss said...

I mean, it has no *natural* cause.

Michael Gonzalez said...

If it all coexists, why is the front edge any less caused or explained than any other part? No one thinks there's such an issue with the edge of any other dimension/coordinate, right?

I think the only reason to worry is of something goes from non-being to being.

Michael Gonzalez said...

Not to harp on it, but to just to make sure my question is clear: If the 4(or more) coordinate block came into existence all together (every point this way or that way, in any of the directions, including the ones we call temporal, just popped into being all at once) then we would rightly wonder what the cause of that popping-into-being was. Its shape, or its edges, in any of those coordinates would neither add to nor take away from that issue.

So, likewise, if the 4+ coordinate block has always existed as it is, then, regardless of its edges or shape, we just never have to ask how it got there or who caused it. We have still the Leibnizean sort of worry, but the shape doesn't affect that either.

I think it's clear that the atheist is only worried if the natural world came into existence from non-being, because that sounds like something a non-natural thing would have had to cause. Now, they are stuck with the evidence, and they have to say things like "the Universe is 13.7 billion years old". On a B-theory of time, I don't see why we should call the Universe any number of years old; or, at least, I don't see what that fact would have to do with how extended the Universe is in one or more of its coordinates....

Anyway, like I said, I probably just don't have the right intuitions for this. I have yet to hear a description of eternalism or B-theory that didn't misuse words like "exist", by violating their proper tense. Nothing "exists" or "is equally real" or "is" anything except in the present tense. So, as far as I can tell the whole position (to use Peter Hacker's phrase) "transgresses the bounds of sense". It literally makes no sense.

Fr M. Kirby said...

2 appears to be ambiguous. It could mean:
2a. A non-existent thing cannot be changed from a potentiality for something into that something actualised. OR
2b. A non-existent thing has not been actualised. OR
2c. A non-existent thing is not presently actual.

If 2a, then the argument breaks down as 3 becomes "Therefore some no longer present potentialities must have once existed in order to be changed into the present actualization of their potential".

2b and 2c are arguably tautological, but are also clearly tensed, and so cannot help the eternalist cause. If one insists the tense-ambiguous original rendering cannot or must not be clarified temporally, one has begged the question in favour of eternalism. A similar objection could be made to 7.

Personally, I am not sure I am comfortable with either presentism or eternalism as usually expressed. I wonder whether greater attention to the analogy of being might resolve the issue more satisfactorily. But that's more intuition than conclusion.

Alexander R Pruss said...


Causation usually goes from past to future, and physical events not on the past boundary typically have physical causes further back in the past.

Michael Gonzalez said...
This comment has been removed by the author.
Michael Gonzalez said...


If the whole block Universe came into being all at once (4+ dimensional as it is), then the cause of each spatiotemporal section is the same, and is simultaneous. If it has always existed as it is (4+ dimensional), then each spatiotemporal section is either a brute fact or it has the same simultaneous cause (given the PSR, we'd want to say the latter).

In either case, it is simply not true that the sections to the left of, below, behind, or "earlier than" (in your 4d sense) are the cause of the section in question. At least, I don't see how any of the meanings of "cause" apply. An entirely random set of spatiotemporal sections has the very same explanation as one that tells a nice linear story when... I guess... you "look at" the block and scan from the "earlier" side to the "later" side?? As I say, my intuitions for dealing with this block are probably rubbish.

Let me put it this way (sorry for being so long-winded; I'm just genuinely confused about eternalism): Ignore that the 4th dimension is called "time", and that this way is called "earlier than" and that way is called "later than". Suppose there is still an eternally existing, static 4d block, but it has x, y, z, and q coordinates, where q is just another spatial dimension. This block is all that (physically, at least) exists. The parts "qurlier" (a direction of the q coordinate) and "qater" (the other direction of q) seem to show a linear progression (entropy increases, etc) if you scan the block from the qurliest to the qatest boundaries of the block. Still, no one thinks that that has anything to do with causation. Because, after all, God has just eternally sustained this 4d spatial-only block, and therefore is just Himself the cause of each section.

I don't see how you add anything but verbal manipulation by changing "q" to "t", and using tense-talk about the sections of "t". After all, we can still ask all the same questions we would ask about the overall block and its sections. To say "causation usually happens from this direction in q to that direction (from qurlier to qater)" would be... well, nonsense, wouldn't it?

Alexander R Pruss said...

There can be causation even within a single time: simultaneous causation is like that. Take Aristotle's example of the man moving the arm which moves the stick which moves the stone.

Now, there is an epistemic question: Why should we posit causation within the block? One answer is that we need it for ethics. Another is that our best explanatory stories include such causation.

Michael Gonzalez said...

I agree there can be simultaneous causation, but our conceptual grasp of causation at all is based on our experience of being active, dynamic causes. We know first-hand that dynamic causation is real, and then extrapolate to more esoteric cases. But, if the block view is correct, then all causation (if there is any) is simultaneous. It makes me wonder how we'd ever get the idea of causation in the first place. But, then, I don't understand how we ever get any ideas or think of anything if we are frozen 4d shapes....

So, the 4d block may have always existed or it may not (God could bring a 4d block into existence, or He could eternally have been sustaining one). Whether it has edges in this or that direction of any of its coordinates doesn't really change that or answer that question at all, does it? And it's hard not to see God as the cause of everything, since He simultaneously and equally sustains the putative causes and the effects. On a natural view, at least we have the active powers of animate beings producing effects. On the static block view, it's all just a painting; and God is the One simultaneously painting the later and the earlier stated of affairs, no?

Alexander R Pruss said...

I think on any orthodox theology, God is beyond time and sustains things at all times. But sustaining is not at all, I think, the same as producing (pace Leibniz).

Michael Gonzalez said...

It just seems like God is the only active agent (and not really active, at that) in a block/eternalist worldview. The rest of it just is, unchangingly and statically.

Rob K said...

Do you have a standard definition of 'presentism'? Are you assuming an actualist account of the quantifiers? Here's a version of possibilistic presentism that seems compatible with Aristotelianism: every actual thing exists in the present, but there are merely possible things in the past and future.

Alexander R Pruss said...


I was thinking that it says either more weakly that only present things can exist or more strongly that to exist is to exist presently or that to exist presently is to exist.

Yes: your version seems compatible with Aristotelianism. And it's really, really interesting. I think, though, it fails to satisfy the intuitions of the Three Horse Problem:

Alexander R Pruss said...


BTW, possibilism would let one reduce quantifiers to infinitary boolean operators. That would be a nice reduction.

El Gerente said...

What is an example of a simultaneous causation going on wherein event B is the actualizaciĆ³n of simultaneous potential A? Is there any real world example of this?

Alexander R Pruss said...

I have no idea, but I suspect that something mental would be an example.

Suppose God creates a fully-formed agent (say, an angel or an adult human) and in the first moment of its existence, the agent thinks something. That thought is an actualization of a potential.

Michael Gonzalez said...

Perhaps this is stupid of me, but I actually think of pretty much all cases of causation as simultaneous. After all, the actualization is tipped off at the very instant that the causal conditions are in place. Not a moment before or after.

Rob K said...

The mutual annihilation of a particle and anti-particle and the creation of a photon (or vice versa). The transition of an electron from one energy state to another, via the absorption/emission of a photon. And so on. Many cases in particle physics