# God and Time I: Metaphysics

I've been asked to write about the relationship between God and Time.  I believe that God is not a part of Time, that he is eternal and unchanging, and that therefore he knows (what we consider to be) past, the present, and the future equally.  I believe that there are good reasons to believe this coming from 3 different fields of study: 1) metaphysics, 2) physics, and 3) biblical theology.

(Of course, it is also true that the Son of God

came down from heaven and was incarnate by the Holy Spirit and of the Virgin Mary, and was made man.  He was crucified for us under Pontius Pilate, suffered [παθόντα, which can also mean "was passively acted upon"] and was buried.  On the third day...

In other words, he united himself to a human being who was, like us, part of the flow of time.  In this sense, God is in Time, but to allow this to be truly and properly a life-giving paradox, we need to assert that it was the Eternal and Immortal who suffered and died for us.  The more we anthropomorphize the divine nature, the less significant is the Incarnation.)

In order to address this question, we need to know two things: what is Time and who is God?  To some extent we can begin to explore the metaphysics of Time without discussing who God is, although eventually we must place every created thing in the context of the One who created it.

So let's start with Time.  There are two main views on this, which are rather boringly called the A-theory and the B-theory (although there are variants I won't consider).  This is, as far as I can tell, due to a 1908 article by the philosopher John McTaggart arguing for the Unreality of Time.  McTaggart was basically a Hegelian mystic and yet, despite the later backlash against Hegel in the subsequent era of Logical Positivism, this paper has became one of the foundational articles for contemporary Analytic Philosophy!

(Recently I've been reading the records of the Oxford Socratic Club, a club for debate between Christians and Atheists/Agnostics, of which St. Lewis was President, whose Digest has recently become available from Lulu thanks to St. Joel Heck.  The talks were given around the time of WWII, which was a particularly interesting time for Philosophy since it was during the overlap period when both Idealism and Logical Positivism were taken seriously.)

Anyway, the A-theory (a.k.a presentism) claims that time flows from the past to the future, in such a way that neither the past and future really exist, but only the present moment is real.  However, the past was real and the future will be real, since time is really flowing from past to future.

The B-theory (a.k.a. eternalism) claims that all times (past, present, and future) exist equally, and that the word "present" is like the word "here", an index to refer to the location of the speaker within the timestream.  Thus, there is no objective fact about which time is really "present", any more than there is an objective fact about whether "here" is located in the USA or Australia.

One of my commenters explained the difference in this way:

The first is called the A-theory, or tensed time. Only the present is real; the past and future do not exist. The second is called the B-theory, tenseless time, the block view of timespace, or Minkowski or Minkowskian spacetime. All of time—past, present, and future—is complete and actual in this view. In some unperceived way, all of time is occurring now.

I mostly agree with this statement (although I'm not sure what "complete" means) but take issue with the last sentence.  The B-theorist would not say that all of time is literally now anymore than we would say that all places are here.  The past indeed exists, but does not exist "in the present" because for an A-theorist that means "at the same time as the speaker is located."

Really what that last sentence does is explain the B-theory view in terms of the A-theory view.  According to the A-theory view, only the Present moment is real.  Saying "all times exist now" is really shorthand for "The B-theorist ascribes to the Past and Future the same type of reality which the A-theorist only ascribes to the Present."

Can we return the compliment and describe the A-theory in terms of the B-theory?  Actually we cannot.  If all you have are B-theory ideas, there is no way to make the A-theory clear.  If an A theorist says that the past does not yet exist, the B-theorist will translate "does not yet exist" to "exists at a moment $t_1$ previous to the current moment $t_2$", and if he says that the future is going to exist, she translates this to mean just that the future is in the future!

In this sense the A-theory contains a vicious circle in it, as pointed out by McTaggart (although I don't agree with his conclusion that time is therefore "unreal").  When we say that a physical object is changing or flowing, this means that it changes with respect to time, that if we plotted it out on a graph, there would be a physical parameter $x$ such that the time derivative is nonzero: $dx / dt \ne 0$.  When we say that time itself is flowing, either we mean $dt / dt = 1$ (time goes at one second per second) which is a trivial calculus tautology which says nothing, or we mean that it is flowing with respect to some other meta-time coordinate.  But that's absurd, if we can only explain time with respect to a deeper time.  (And if that deeper time "really flows" we will need a 3rd timestream to parametrize that, and so on.)

It's like those time travel stories where somebody goes back and changes the past.  But if you think about it, that's a crazy contradiction.  Time just is the way we parametrize change.  The moments of time cannot themselves change or flow in the same way that things change or flow, since there is no other timestream to parametrize their change.  (Well, maybe in science fiction there is, but in the real world there's no reason to postulate this.)

We can put it another way.  The A-theorist maintains that the past and future do not exist.  But if this is true, it is impossible to distinguish it from a radical presentism in which one maintains that only the present moment will ever exist.  Suppose that right now (e.g. 9:18 pm March 2, 2015) is the only instant that will ever exist.  The past is just a delusion of our memory, and the future is a just delusion of anticipation.  None of it is real.  Clearly an absurd form of skepticism.  But really, the A-theory implies this.  For it says that the future exists only in the future and that the past exists only in the past and that both of these are forms of nonexistence.  So the future does not really exist, and neither does the past.  No amount of protesting about the fact that the future is going to exist or the past having existed implies anything about it actually ever existing, unless you secretly smuggle in the B-theory view that these modalities refer to ways of existing.

One might worry, though, that the B-theory is radically foreign to our own experiences.  Whatever we say philosophically, isn't it obvious if we inspect our own conscious experiences that it feels as if time is ever flowing and changing?  Each moment is so slight that we hardly grasp it before the next is upon us.

I admit that this worry has some psychological tug on me, but in the end I don't think it implies the A-theory.  After all, it also feels as if my own experiences are more real than the experiences of others, and that here (wherever I am) is more real than there (wherever I am not) but these things I am happy to discount as illusions, without incorporating them into my metaphysics.  Furthermore, my brain cannot really detect a single instant: it takes a second or two for me to consciously process my sensory data.  Thus what I experience as now is always really a moment that has a finite amount of thickness in time.  If only the a single instant existed at once, that sliver would actually be too small for any conscious experiences to fit inside of it.  But if more than one instant can exist, it is simplest to say that they all exist, but that my self simply does not experience them all together in one lump.

Thus I conclude that only the B view makes logical sense.  Some might say that this means Time is an illusion; but I would instead say I am asserting that all of Time is real.

Now if God is omniscient, then he experiences everything as it actually is.  But we have seen that the idea that time itself "flows" and "changes" (as opposed to saying that things change with respect to time), makes no sense.  If the B-theory is correct, then God must experience it as being correct, that is he must himself be eternal and unchanging.

But this is also what we would conclude if we instead started with the nature of God as understood by classical theism.  Here, you will recall, God is conceived of as the fundamental being whose existence is explains everything else.  As I argued before, the fundamental reality, however we conceive of it, must be eternal:

If the fundamental entities are necessary, then it stands to reason that they are also eternal, since something that exists necessarily cannot come into being, or cease to be, or indeed change in any way.  They must just exist timelessly.  Besides which, if they explain what happens at all moments of time, it doesn't seem plausible that they should only exist for certain moments of time.  For similar reasons, one can argue that the fundamental entities can't be limited to just one region of space.  Their influence must be present everywhere.

For God to be in Time, would mean that there is a part of God which changes and develops and changes, even if it is only the part that observes "what time is it right now".  But that would mean that God is actually divided into pieces, some of which (the past versions of God) help to explain others (the future versions of God).  This is inconsistent with the unity and eternity which befits the divine nature, which is fully real and cannot pass away like shifting shadows.

This is why proponents of Classical Theism have generally maintained that Time, rather than being some Metaphysical Ultimate, is actually part of created reality.  It exists contingently as part of the physical world, because God created it.  This view was developed by Philo, St. Augustine and others, but in the next post two posts we shall see that it is also supported by modern physics: especially Einstein's theories of Relativity.  Then in the third last post posts I will argue that the view that God is eternal and unchanging is also to be found in the Bible.

Next: Special Relativity

I am a Lecturer in Theoretical Physics at the University of Cambridge. Before that, I read Great Books at St. John's College (Santa Fe), got my physics Ph.D. from U Maryland, and did my postdocs at UC Santa Barbara, the Institute for Advanced Study in Princeton, and Stanford. The views expressed on this blog are my own, and should not be attributed to any of these fine institutions.
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### 71 Responses to God and Time I: Metaphysics

1. Ileshia says:

Whoa

2. Excellent! Thanks.

If you are right about B theory, and the past and present exist in some sense, then that means (I guess) that the people who lived in the past and have died, still exist in some sense. And it means that an infinite number of 'me's exist, for time is linear not digital.

Am I thinking right there, and does that make B theory harder to believe?

3. Aron Wall says:

Eric,
Well, we don't really know whether time is continuous or discrete; some physicists think it may be discrete at the Planck scale (the Planck time is about $\sim 10^{-43} s$)). But we can't measure times that tiny. For all practical purposes, it is a continuum.

I don't know whether it makes it harder for you to believe, but it doesn't make it harder for me to believe it...I don't think it's too hard to swallow that my grandmother's childhood in some sense exists and that there are many different versions of ourselves. You could argue that we treat this both of these things as being true for practical purposes: we are always talking about the past as though it were still relevant to life simply because it happened, and we are always talking about how we used to be different in various respects.

4. Robert Childress says:

I'm looking forward to more of this series.  I'm sympathetic to the B-theory of time, specifically because of how well it fits with the concept of the God of classical theism and God's omniscience, but I haven't yet found my conception of the thing very convincing.  I haven't studied it much, though.  I'm assuming the conception I hold is ill-formed.

I admit that thinking time flows at one second per second doesn't really tell us anything, but there are some aspects of reality that I recognize are difficult to explain.  Some of that I simply chalk up to my lack of ability to understand, and my inability to express the passing of time as a meaningful relation might be one of those things. This isn't entirely satisfying, but I liken it to taking external reality for what it appears to be and conforming my mind to work with it rather than trying to conform external reality to something more workable by my mind.

I also recognize the B-theory fits better with some aspects of physics – I'm looking forward to seeing how you cover this. The manner in which time seems to be bound up with space is very interesting, and how an observer speeding through space also speeds through time is fascinating. There's also something interesting about how we can essentially store data in the world and send it to the future – for example, by leaving a note somewhere. But I still can't map these interesting qualities of external reality to a belief that the future is just as real as the past is just as real as the present. I'm not clear on how we can have any assurance that the future exists until we actually “get there,” at which point it is no longer the future. I'm not clear on how we can have any assurance that the past exists, as there doesn't appear to be any way to actually visit it.

If time is a physical property and if the past and the future are as real as the present, then I would expect there to be some way of verifying that the past and the future actually exist.  For example, when dealing with space, if I say that I was born in a particular city, I can travel to that city to see if it exists -- or perhaps try to inquire about the nature of its existence through some means of communication. But it's verifiable. If I say that I was born in a certain year, do I have any method of verifying whether such a time exists?  I can point at something "over there" and then head "over there" to verify its existence.  Can I point "back then" and then head "back then" to verify its existence?

I know analogies (in this case, between space and time) don't have to be parallels in every respect.  Referring to time as being like space just seems insufficient.  Time makes sense as an abstract concept of understanding how physical events are ordered to prevent them from overlapping when in the same space, and to that end I think it makes sense to use time as a coordinate alongside spatial dimensions to better describe some particular state of affairs, but I'm not convinced that any of that implies that the past and the future are as real as the present.

I also don't understand the logical problem of saying that neither the past nor the future actually exist.  I don't think that's the same as saying that there was never a certain state of affairs which could be described using the concept of time as a part of the coordinate system that comprises that particular state of affairs.  I can imagine building a model describing something that does not exist (or that no longer exists).  The truth value of the claim that such a configuration once existed might be open to dispute, but I don't understand why we would have to say that if it doesn't exist in the present then it never could have existed.  Is there a problem with simply saying that our use of tenses when describing the timing of events is merely a useful turning of phrases?  Can we not refer to things that do not exist in such a manner that the meaning we are trying to convey about those things is understood, even if the referents to which the terms are pointing do not exist as an actual fact of present reality?

I'm also not satisfied by the B-theory's handling of conscious experiences.  It doesn't seem to adequately explain the "forward" directedness of our conscious experiences through time.  What's preventing us from becoming "unstuck" in time, like Vonnegut's Billy Pilgrim?  Why am I only conscious of time moving in a certain way (or of me moving only in a certain way through time)? And I think the problem is more than my mere sense that time is passing.  There's a sense of a very real and existing me which is comprised of an accumulation of experiences over time.  If each "version" of me exists equally in time, where is the adaptive continuity between me at one moment of time and me at another moment of time – how can the "I" that I recognize as myself be something that is growing and changing, as it seems to be? What glues together all of these versions of me through all of these time slices, and why am I not conscious of them all?

Our inability to perceive a single "instant" of time hasn't been very problematic for me, but I might not understand it.  Presumably, whatever comprises an "instant" of time contains some small amount of sensory experience that is consumed, creating extremely small and (in and of themselves) imperceptible changes in my physical composition. Such changes gradually accumulate until they form a sufficient change of state to have expressed itself as a full conscious experience – whatever that might be. I could think of it in a similar way to how evolution seems to work with the differentiation of species – where a species doesn't just immediately change, but the changes happen gradually. Given enough time, you have species of creatures that are very different from one another, even though the moment-to-moment changes weren't perceptible. Granted, under this view, whatever we are consciously experiencing in the “present” would not actually be in the present. Our “present” consciousness would always be an analysis of data that refers to an external reality that no longer exists. Nevertheless, the internalized models that our consciousness is analyzing (of some certain state of affairs that previously existed but does so no longer) would be a close enough approximation to present reality for us to function normally.

In short, I don't know why our conscious experiences must depend upon a big piece of time. We might not be conscious of a tiny instant of time, but the steady accumulation of tiny changes occurring through successive moments of tiny instants could be building blocks of our conscious experiences.

With all of that said, I'm not really satisfied with the A theory of time, either. I'm assuming, though, there's just something I don't get about all this. As I said, I'm looking forward to your future posts. And I don't expect you to take the time to respond to all of this – it grew monstrously larger than I intended.

5. Aron Wall says:

Robert,
Contrary to the logical positivists, there are plenty of real things which are not directly verifiable, but are nevertheless reasonable to believe in. For example, the existence of other minds. Or the inside of the moon. You could say that without the inside of the moon existing, the outside would collapse inward, but that is an indirect argument---it is also true that the past is necessary to explain what is happening in the present. Really the existence of anything other than our own sensory and mental perceptions. Actually our evidence for most things is indirect!

Also, when you verify that the sun exists by e.g. looking out the window, or that Rome exists by e.g. checking its Wikipedia article (that's how one does it, right?) actually you are only confirming that it existed until recently in the past (however long it takes for light/updates to travel to you). So actually, your argument shows that we can verify the past, not the present. (You could say, well by golly I could just get on a plane and check to see if Rome is still there! But you can only succeed in the future, so if you don't believe in the future that doesn't count.)

As for 5 minutes in the future, it's quite true we can't know for sure it exists (since the world could end before then). But that's irrelevant. So long as we reasonably believe that the future will come to pass, then unless this belief is meaningless, we must be asserting the existence of something.

One could put all this another way. Leaving aside certain types of conceptually necessary truths such as logical consistency, the only reasons I can think of to believe in the existence of anything are as follows:
a) it is a matter of our personal present experience,
b) it is an entity postulated to explain the stuff in (a), or
c) its existence is also implied by the stuff we postulated in (b).

Now (a) by itself only tells us that our present psychology exists. But every event in category (b) resides in the past (*). By means of (c), we get the future, the rest of the present, and some more of the past. Strictly speaking only (a) can be verified.

Thus, the past and future should be held to exist simply by following the usual rules (a-c) for deciding whether to postulate entities.

Presentism is now the quite arbitrary stipulation that nothing in (b) should be affirmed to exist, but things in (c) should indeed be affirmed to exist if and only if they are "simultaneous" with the things in (a). But why should we believe that anything in category (c) really exists, if nothing in (b) really exists?

And how can the things in (b) explain the things in (a) if they do not really exist? An A-theorist might reply "But they did exist in the past!", and I reply "On your theory, that is the same as saying that they don't exist, so that doesn't help you at all."

(*) a slight oversimplification since certain philosophical approaches allow for "simultaneous causality".

I also don't understand the logical problem of saying that neither the past nor the future actually exist. I don't think that's the same as saying that there was never a certain state of affairs which could be described using the concept of time as a part of the coordinate system that comprises that particular state of affairs. I can imagine building a model describing something that does not exist (or that no longer exists).

If the things we think of as being in the "past" never really existed, we violate the metaphysical principle that nothing can be caused to exist by something which itself does not exist.

If the things in the past "used to exist but no longer exist", then I ask for a noncircular definition of what it means to say that they "used to exist". None can be provided, since anything you say will be tantamount to saying that the "past existed in the past" which defines the term past in terms of itself. One can meanigfully assert that "In the world of Narnia, things in Narnia exist", but that gives us no reason to think that Narnia is anything other than purely imaginary, since "Narnia does not really exist". How is saying "In the past, things in the past used to exist" but "The past does not really exist" any different from that?

One could of course imply that "past" should be taken as a "conceptual primitive" which have intuition for, but which cannot be explained in terms of other things. I'm not sure I have a watertight argument against this. But that still seems like an extremely odd thing to say, since normally conceptual primatives are things we have to postulate the existence of in order to explain everything else. Not things we have to postulate the nonexistence of to explain everything else!

I'm also not satisfied by the B-theory's handling of conscious experiences. It doesn't seem to adequately explain the "forward" directedness of our conscious experiences through time...

As for the psychology of time flow, surely a large part of that could potentially be explainable by neurological and psychological theories about how our memories and perceptions work. B-theory metaphysics doesn't need to explain everything by itself. Anyway, the fact that we remember the past and anticipate the future is enough to at least give our experience of time a specific directionality.

With respect to my comment about not being conscious in a "single instant", I was assuming that the reason our brains are conscious has to do with the fact that they process information over time. I guess I was assuming that no single "instant" in that process would be conscious any more than a chalk diagram could ever be conscious. But these "functionalist" intuitions might be wrong. At any rate, it is far from obvious that what we are conscious of is a strict mathematical instant of time (rather than a fraction of a second).

6. Drew says:

Dr. Wall,

First of all, I would like to thank you for running this blog. Your writing, in particular your series on fundamental reality, has really helped me rekindle my faith.

In regards to the theories, I agree that, after seeing the explanations, the A-theory does not stand up well on its own. But, for me at least, the B theory raises more questions than it answers. If all time exists "now," it begs the question: why do we only go one way? Indeed, why does everything we observe go one way? In all other spatial dimensions we see the ability to go two ways: left and right one-dimensionally, up and down two dimensinally, and forwards and backwards three dimensionally. Why would time be treated as the exception to this, beyond it being radically different from spatial dimensions?(i seem to remember seeing a post from you explaining what people mean when they say time is the 4th dimension, but can't for the life of me find it). Why do we experience it in single-frame snippets? If it all exists 'now,' and in a relatively uniform way, why are the ways we conceive the past and the future so radically different from both each other and the present? And why do we experience it in such a way that it appears to be constantly moving?

Now I will be the first to admit, being a high school student, I'm a philosophical autodidact. I am not terribly well read in physics or metaphysics, and likely many of my questions have been or will soon be answered by you or another in another work. But I was running this over in my mind today, and had an idea.

As you know, in classical mechanics, energy is always conserved. It exists, however, in different forms. The best demonstration of this i can conceive is a ball sitting on a ledge several feet up. At the beginning of the movement, the ball has purely potential energy. When it falls from this ledge, that potential energy begins to transfer into kinetic energy. At the end of its descent, before making contact with the ground, the ball is purely kinetic energy.

Could time behave in a similar way as this? Existing all at once as a whole, just as mechanical energy does, but in different forms, like potential and kinetic? In this view, the way I conceive it, the future is the 'potential' energy, ans the past 'kinetic.' Each has different properties and are treated differently, just as potential and kinetic are. But both are 'time' just the same, in the same way potential and kinetic energy are both energy. All 'time' exists, but in these two forms.

To me, this answers the objections that Taggert raises in his famous paper, as the property of time alters throughout, instead of remaining static, introducing an element of change. It answers my objections, as the present moment we experience would be the observation of this change, and the reason we can't move forwards or backwards would be much the same reason kinetic energy can't change to potential all on its own. Our varying conceptions of its various parts are different because the properties of each are different..

The only objection i can see to this would be what time changes in relation to. Irreversibly in my mind, change requires a time to work with in regards to, and as mentioned earlier in the comments it cannot change in relation to another time. Could it be possible it changes in regard to motion? Or matter? it will require further development to answer these questions, if they can be answered.

I would like to know how you would answer the objections posed, what you think of the idea, and if it is even a coherent notion.

Once more, thank you for the writing Dr. Wall, and thank you for any answers you can give me.

[Fixed the HTML formatting. You just gotta put the \ before the I in the end italics html tag, and don't include any spaces---AW]

7. Robert Childress says:

Hey Aron,

I certainly didn't mean to imply logical positivism, so much as to indicate how drawing analogous parallels between space and time doesn't help me understand or "picture" time from the B-theorist's perspective, because my perceptions of and interactions within time seem quite different than those within space. The "present"/"here" parallel is kind of lost on me, as our exploration of time is not (or does not seem to be) much like our exploration of space.

I'm not convinced (yet) that the B theory is a required explanatory postulate for our present experiences, though. For me, it raises more questions than it seems to answer. And I'm not sure I fully recognize the need to describe prior existence in a non-circular manner -- I'm still considering that. It could simply be a situation where my ability to describe something is too limited to adequately explain the phenomenon. I get that the A theory has problems, but the B theory seems to postulate things that I do not (yet) perceive to be necessary and entails some other difficult to image aspects of reality, and then foists those difficulties off on other fields.

None of that makes it wrong, of course, I just feel like there should be an option C somewhere.

8. Aron Wall says:

Drew,
Thanks for your comments. I'm glad you found my series on Fundamental Reality helpful, and I pray that your knowledge and love of God will be an increasing function of time!

Your question about time really boils down to 2 separate physics questions: 1) why is time so different from space, and 2) why is the future direction of time different from the past direction?

The answer to #1 (which is in that post you are thinking of: Time as the Fourth Dimension?) is that the time dimension is not the same as the space directions, because when you write down the analogue of the Pythagorean theorem, time^2 comes in with a minus sign compared to space^2 (in units where the speed of light is unity: $c = 1$. This is the fundamental difference which makes time completely different from space. In particular, there is a lightcone in time, and particles with mass must travel within that lightcone, i.e. slower than the speed of light. In other words, everything moves faster through time than through space.

Now why is the future different from the past (#2)? This is particularly perplexing because the fundamental laws of physics are basically symmetric under reversing the past and the future (aside from very tiny differences in the weak force, which are not important in daily life).

The usual answer here is the Second Law of Thermodynanics, which says that a number called the "entropy", which basically measures the number of possible ways for the universe to be, is increasing with time. Why is that true? The best answer is that the universe just started out in a very special low entropy state, and then as time passes, statistics tells us it is more likely to end up in a higher entropy state (see part II of this article I wrote). Why did it start in a low entropy state? Nobody knows, maybe God just started it out that way, or maybe there is a physical explanation we don't understand yet. So basically the distinction between the past and future is due to the initial conditions, not the laws of physics.

At the end of its descent, before making contact with the ground, the ball is purely kinetic energy.

Just minor quibbles about language: I would say "has" rather than "is", since the ball is lots of other things (e.g. rubber). Also, clearly if there were a hole in the ground, the ball could fall more, so that even more potential energy could be converted into kinetic energy. So I would not say it has "purely" kinetic energy. (Actually the question of which height counts as "zero" potential energy is a bit of an arbitrary convention; you could set it to be wherever you like. If you decide that a ball way off in space should have zero potential energy, then the potential energy of a ball on the surface will be negative.)

Anyway, your analogy to potential/kinetic energy is interesting (although we physicists usually get grouchy when people make analogies about physics unless they can make them mathematically precise using equations!), though I would note that in the case of energy the conversion can go in both directions. But I think the real difficulty is the one you (and McTaggart, and me) raise here:

The only objection i can see to this would be what time changes in relation to. Irreversibly in my mind, change requires a time to work with in regards to, and as mentioned earlier in the comments it cannot change in relation to another time.

If you have one type of "time" converting into another type of "time", that seems to presuppose a notion of change or flow, and therefore it seems to me it cannot explain time...

9. Jack Spell says:

Aron,

This is quite a thought-provoking post. I'd like to comment on the part at which you stated the following:

For God to be in Time, would mean that there is a part of God which changes and develops and changes, even if it is only the part that observes "what time is it right now."

I don't think this follows, at least not in the sense that you seem to suggest: God can exist "in Time" without changing intrinsically; rather, on a relational view of time, He can be "in Time" if He changes merely extrinsically.

To give an example: Suppose that at some point in the past my max bench press was 275 lbs. and yours was 250 lbs. Thus, in relation to you, I would be said to be stronger than you. But suppose that now, in the present, your max has increased to 300 lbs. while mine has stayed the same. Thus, the relation has changed so that now you are stronger than me. This is so even though I have experienced no intrinsic change to my strength--indeed, my max stayed the same. But I have experienced an extrinsic change--indeed, I went from stronger than you to weaker than you, despite my max staying the same.

In the same manner, God can exist temporally without changing intrinsically.

10. TY says:

Thank you Dr. Wall.
This series on "God and Time” already promises to be another great discourse as "Fundamental Reality" and "Did the Universe Begin?”
I agree with many of the readers’ comments that your writings bring a refreshing look at puzzling questions involving Physics, theology, and philosophy. And just when we become too comfortable with the received knowledge, you shake things up without being heretical.
And I can tell you that your posts have helped settled many questions that I had struggled with for years and in, the process, this understanding has bolstered my Christian beliefs.

11. Aron Wall says:

Jack,
You make a good point, although I think I would express it differently.

If God only "changes" in an extrinsic, relational sense, I think this is the same as what I would mean by saying that God is not in Time. Rather, it is the things he is in relation to (created, temporal things) which are in Time. Just as God can know contingent things, without himself being contingent, he can know temporal things without himself being temporal.

Thus, I think the actual conclusion of your argument should be that if one is an A-theorist, one could still believe in divine atemporality (I believe this combination was the Scholastic view).

However, in this post I have argued that the A-theory is absurd considered in itself. And I still think it is true that on the B-theory, God cannot be temporal without having temporal parts, since in the B-theory that is what it means to exist for an extended duration. Instead he is eternal, i.e. timeless (and therefore equally "present" at every spacetime point).

12. Charles says:

Hello Dr. Wall

I've heard of some philosophers that the Kalam cosmological argument is not relevant in a B-Theory of time because the causality principle would not apply.

13. Aron Wall says:

Charles,
Which philosophers say that? Some B-theorists think that there's no such thing as causality, but others (like myself) think it is still an important concept. However, as I've said before, I don't think Kalam is the most convincing form of the cosmological argument.

14. James says:

Opponents of the doctrine of divine eternity argue that If God is timeless, He does not exemplify some properties as States of Consciousness, Intentionality and the Inter-Personal Relations, If God does not exemplify these properties He is not personnel

William Line Craig gave an answer to this problem, but it seems that he believes God is temporary with the creation. http://www.reasonablefaith.org/divine-timelessness-and-personhood

15. David says:

Aron,

William Lane Craig and Quentin Smith wrote a book where they team up and argue for the Lorentzian interpretation of relativity, and indefense of the de Broglie-Bohm interpretation of quantum mechanics (I haven't finished reading it yet but they wrote it with a few fairly prominent Bohmian physicists/philosophers e.g., Anthony Valentini, Tim Maudlin, Craig Callender etc). I didn't really think this view of relativity was taken very seriously, I'm only doing my Bs.c in physics so I'm not in a position to make a great judgement about this. But Quantum foundations is the area of physics which I find most fascinating.

I believe the Michelson-Morley experiment and the fact that quantum field theory is formulated with a non-Lorentzian view have tempted most physicist always from this (but they point out that in the philosophy of time the Einstein interpretation as opposed to the Minkowski interpretation is still popular). Bohmian mechanics I think has some problems in QFT (e.g., with non-locality) it also had a preferred refrence frame, but in quantum gravity it's seems pretty good. For example, you have the WDW equation which can lead to the problem of time, but since in Bohmian mechanics you have two separate equations one is the Schrodinger equation and the other you differentiate for the motion of particles, when you apply that to the universe you have also two different equations (i.e., the WDW equation and one describing the evolution of the universe).

I was wondering, is it at all plausible or taken seriously in your experience (the Lorentzian version of relativity), I think it has some strong motivation from Bohmian mechanics, but I tend to prefer Consistent Hostories.

16. Aron Wall says:

David,
Neither Bohmian mechanics nor the Lorentzian (aether) version of relativity are taken seriously by most physicists. Only a small minority would embrace these options. There is little agreement on what is the correct interpretation of QM (both many worlds and consistent histories are popular), but I think the large majority have pretty much an Einstein/Minkowskian interpretation of relativity (which are not generally viewed as inconsistent with each other.)

17. Aron Wall says:

James,
In my Fundamental Reality series, I tried to argue for the plausibility of a being which could be both fundamental (and therefore plausibly timeless) and also like a mind in some respects. But I think it is dangerous to think that we can imagine God's consciousness, and think of him as being personal in the exact same limited sense that we are. Rather he is conscious in his own, totally complete way.

In the context of Christian theology, what makes persons persons is their capacity to be in loving relations with other persons, patterned after God. God is personal precisely because he is a Trinity of eternally communing persons. For this reason he also reveals himself to us temporal creatures as being personal, ultimately through the paradox of the Incarnation of the eternal Son of God as a particular (temporal) human being, and through sending the Holy Spirit into our hearts. In Christian theology, this revelation is how we know who God is in his eternal, essential nature.

We must accept God as he reveals himself to us, and not try to second-guess him as though there were some impersonal notion of divinity which lies further back behind all this. To deny that he is the Absolute Unchanging Eternal Creator or to deny that he is a relatable, adaptive, covenant-making Lord is simply to reject the starting point of the Christian paradox; it is sterile and goes nowhere.

Attempting to make a more approachable, limited deity misses the entire point of the Christian revelation. God has already done the work of relating to us! And it is not by being like us, but by becoming like us so we could become like him. Christ is the Bridge connecting humanity to God: unless the bridge extends fully in both directions it may as well not be there. God is not at all in the image of Man; it is enough that Man is in the image of God, and that the Son of God became Man to reconcile us with the Father.

18. James says:

Hi Aron,

William Line Craig says that the doctrine of creation is inconsistent With the B-theory of time, He observes that:

"If you adopt a tenseless theory of time, according to which all events past, present and future are all equally real, then nothing really comes into being. They just exist at their appointed stations and nothing ever really comes into existence. To say the universe has a beginning on a tenseless theory of time is just to say that there is a front edge to the four-dimensional space-time block called the universe. But if we say the universe really came into being then I think we are affirming the objectivity, the reality, of temporal becoming and therefore a tensed theory of time. On a tenseless theory, I do not think you really have a robust Doctrine of Creation because nothing really comes into being on that view. In fact, the universe just co-exists eternally with God in a relationship of dependency on him. He holds it in being but he never really brings it into being.

Also states that in the B-theory nobody endures through time; you are literally not the same person you were a second ago because you are a different object. That really raises interesting theological problems for, say, divine judgment. Why should the person who appears before the judgment seat of Christ be blamed or punished or rewarded for what some earlier, quite different person-stage did back along time ago?

19. Aron Wall says:

James,
"Just co-exist[ing] eternally with God in a relationship of dependency on him" sounds a lot like being created to me... St. WLC may take "coming into being" as an essential attribute of createdness, but I think the essential attribute is the dependency on a divine author. One side effect of this is that in my view all times are "created", not just the first moment.

Actually not everyone who endorses the B-theory would say that different moments of a person are different objects. Some would say you are one object which persists in time. It's not any weirder than being one person even though you are made of many physical parts. (But I suspect the difference between these views is not really meaningful.)

I may be a different person than I was a moment ago, but there is also a substantial amount of similarity. Good enough for me. (Which of me? All of them I've asked.) I don't think there's a "fact of the matter" about when things have changed enough to be a metaphysically different entity. I think it's a matter of degree. I assume that the Resurrection me will differ from the actual me in many ways, but that God is clever enough to know which aspects of who I am are really important.

20. James says:

I have one last question, knowledge of God of the past, present and future in the B-theory is a model perceptualista of divine knowledge, according to which God "sees" what is happening in the world, not believed to be an anthropomorphic conception of knowledge of God?

21. Aron Wall says:

Is "model perceptualista" a technical term? I've never seen it before. Obviously by saying that he knows anything at all, we are making a comparison to human beings, using some degree of metaphorical reasoning. But we should remember that his thoughts are fundamentally different from our own. Any similarities are due to God creating us in his image, they should not be based on us remaking God in ours. Isaiah 55:8-9 is a word from the Lord to bear in mind here.

22. Carson says:

So, today I watched a movie and I won't say the movie but it is new and is about time traveling and I believe that God isn't real it is almost impossible, how would he get the power to create things and how did God get introduced to the world, is he just a God of earth or the universe? I get so confused in all my thoughts that I push aside the ones that I need to figure out what I want to know and I think I just want to know if God is real or not and if time travel is possible im confused, I'm Christian and don't go to church and I really interested in time, God, aliens and life i am also 13 years of age and don't know much and there is no need to criticize me over my literature or grammar I am just a simple guy wanting simple answers, please help.

23. Aron Wall says:

Dear Carson,

1) Time travel is almost certainly impossible. It is purely fictional, not real. Nobody knows how to make a time machine, and it seems to not be allowed by the laws of physics. I have published some technical articles giving some additional reasons why it is impossible.

2) Nobody knows if aliens exist or not. We have never seen any signals from them, but there are an enormous number of different stars and galaxies out there, so they could well exist without us knowing. If I had to guess I'd say they probably exist, but it is just a guess!

3) God exists. We know this because he sent his Son Jesus to the Earth to do miracles and to show us what he is like, and sometimes he still speaks to people today. He is the God of the whole universe, not just this planet: he also made the other stars and galaxies and everything else.

4) God is the most basic thing that exists; everything else exists because he made it. He didn't get the power to create things from anything else, because then that other thing would be the most basic thing. God just starts out with power, goodness, and love, and he is what gives existence and power to everything else.

5) You can find out more about God and Jesus by reading the Bible. One translation that is particularly easy to read is the Contemporary English Version. A lot of people have the King James Version, but it is particularly hard to understand (since it was translated hundreds of years ago). But any version of the Bible you can find will do. You can read the Bible online using this tool. If there are parts of the Bible don't understand, don't worry about it for now, and just think about the parts you do understand. You can also ask God to give you wisdom when you read, so that you can understand it better. God likes it when people ask for this. The Bible says:

"If any of you lacks wisdom, you should ask God, who gives generously to all without finding fault, and it will be given to you. But when you ask, you must believe and not doubt, because the one who doubts is like a wave of the sea, blown and tossed by the wind" (James 1:5-6).

Another good book to read to learn about Christianity is called Mere Christianity. It's by the same guy that wrote the Narnia books, if you've read those.

You should also try to go to Church if you possibly can. The people there should be able to teach you more about Christianity. (It's okay to go to Church even if you aren't yet sure that God is real. It is a place to learn and pray and celebrate life and talk to people.) See if you can convince your parents, or a friend who already goes to church, to take you on Sundays. Or maybe there will be an group meeting for teenagers sometime during the week. If there is a church nearby, you could also find the pastor's email on their webpage, and ask them for a ride, or for information about events you could be a part of.

24. Nick H says:

Hey Dr. Wall

I'm currently investigating the pros and cons of the A and B-theories. Currently, as a follower of Dr. Craig, I'm biased towards the A-theory, but it is nice to see a decent Christian presentation of the opposing viewpoint.

My two concerns with the B theory have been the same since the beginning, and they are as follows:
1) How does this affect the beginning of the universe? What is the purpose of a Big Bang, of an apparent beginning of the universe at all, if the whole thing, past, present, and future included, already exists? Dr. Craig describes causation in a B-theory world as almost nothing more than an illusion. I know many atheists such as Sean Carroll hold to a B-theory and find within the theory some grounds for dismissing an actual beginning of the universe and thus a need for God. How do you avoid this?

2) The subject of fatalism. If the whole future already exists, why even bother with anything? Is there room for free will of any kind in a B-theory universe? I don't necessarily mean this in a Calvinism/Arminianism sense, but I guess it could apply to that too. But more along the lines of general fatalism, can this be avoided?

Thanks!

25. Nick H says:

Follow up. You should know I read your post about free will, but I'm really not understanding how it fits. Some clarification would be nice. If the future already exists, how is in contingent on the past (or present) in any way? Do I have a choice to eat that cookie? In the future, if I'm already eating the cookie, I really don't ha the choice, do I?

26. Aron Wall says:

Nick,
First of all, I don't think we should pick a theory of time simply in order to make it easier to prove the existence of God. I think there are already lots of good reasons to believe that God exists, and if certain particular arguments for the existence of God fall through, God is going to go on existing regardless... I want to follow the arguments wherever they lead, not adopt premises in order to get the conclusions I want.

Perhaps the A-theory makes it a little easier to make certain kinds of cosmological arguments for the existence of God, but to me it is more relevant that the existence of the classical theistic God (who is eternal and unchanging, and knows the past present and future equally) makes the B-theory more plausible. After all, God should perceive the universe as it really is, right?

Anyway, my main response is that I believe that causality still makes sense even if all times exist. That is, if I go to the shelf and put a cookie in my mouth, my decision to eat the cookie is a cause, and it going into my stomach is an effect, and I don't see why I have to disbelieve in cause-and-effect just because I think the effects and causes both exist. (In fact, it seems like it would be harder to say that there is a real causal relationship between two events, such that only one of them really exists right now. Nonexistent things can't do anything!)

In principle I don't see why cause and effect has any necessary relationship to time. In the real world, causes normally either preceed, or perhaps are simultaneous with, their effects, but I don't think it's logically inconsistent to say that some causes are later than their effects. In fact, the predictions of the biblical prophets about the future may be an example of this.

Similarly, I still believe that some things are contingent (they may or may not have happened) and some other things are necessary (they must happen no matter what), I just don't think this "modality" has anything to do with time. That is, you have free will to eat the cookie because:

a) you are the cause of the cookie going into your mouth, &
b) there was a possible world which was similar to ours, but in which you did not eat the cookie.

I don't see that either (a) or (b) require me to believe that the future does not exist.

Of course, GIVEN that we know you actually ate the cookie, it is not possible for you ALSO to not eat the cookie. But that's compatible with saying that you could have not eaten the cookie, in a different history that was possible, but which turns out to not actually be the case. If we can say "this is definitely the case, and yet it could have been different" about the past, I think we can also say it about the future.

And, if we have the concepts of cause-effect and necessary/possible, I think we can potentially use these to make cosmological arguments for the existence of God, even on the B-theory of time.

27. Kevin says:

Aron,

How is it possible that God is in control of all things and their will is always done, assuming that we are free?

28. Daniel says:

Questions:
1. I can see that the changeless, simple, God is timeless, not timed, unconstrained by discursive thought (so to God, B Theory is His experience-Yes?)
2. and so that for Him, the non-physical, Spirit, the past, present, and future all exist "at once"(?) timelessly?
3. But for my body, a physical, I flow through time and experience A-Theory. Right?
4. If B theory means that "now", the present, is analogous to "here", then why can I not go to the past as easily as I can go to the future?
5. If B Theory means that all times are equally real, then they must be equally real in different senses. Right? to avoid a contradiction?
6. I see from the Scriptures and from philosophy that God must be NOT-timed, eternal, simple, changeless. Can you help me to understand how time can be B-Theory for me?
7. Am I flowing through created time in one direction only--forward, but in 3 directions in space?
8. Why does it seem that I can go "back" in space but not in time? Or can I never go to the same space twice? Does each space have a 4th dimension, making each space I go back to, a different space than the one I was at in the past?
9. Does time seem to be A Theory for me, but B Theory for God?
Daniel

29. Aron Wall says:

Daniel,
I would say that A-theory and B-theory are exactly not the names of types of experiences; instead they describe different views about what time is really like. Assuming I am right that B-theory is correct, I'd answer these questions as follows:

1. Yes, not just because God is eternal, but also because God must experience time as it really is.

2. Yes, so long as we realize that the phrase "at once" is a metaphor (as you presumably intuitvely realize, or you wouldn't have put it in quotes). Obviously it is not literally true that all times exist at one time.

3. Since I believe that B-theory is true, I wouldn't want to say, strictly speaking, that we "experience" something that is false. I would say that we do have an experience that seems like time passing, but if we concluded from this that A-theory is true then it would be going beyond the facts we really possess, and in fact both the past and future are real. Just as, when we look at this optical illusion, we don't have to believe that the lines are bent even though it may seem that way.

To my mind this is the strongest argument for A theory, that it "feels" true that time flows. But---just like I wouldn't want to say that objects that are farther away really are smaller, but only that it seems that way from the laws of perspective---so I would want to say that it only seems like the past and future do not really exist. But it's not that we observe them not existing, just that we don't observe them existing!

4. "Here" and "Now" are analogous in certain respects. They are indexicals, i.e. labels relative to some particular speaker, so all "heres" and "nows" are equally real. (Another example of an indexical is "my": "my car" means the one that belongs to the speaker of the phrase.) But they are not exactly the same in every respect. In particular, even though people call time the fourth dimension, the laws of physics do not treat space and time in exactly the same way.

In particular, one of the laws of physics is that nothing can travel faster than light. Another way to phrase this, is if you use the same units for space and time (e.g. seconds and lightseconds) so that the speed of light $c = 1$, then you are required by the laws of physics to travel at least as fast through space as through time.

This article on worldlines might help. Since you persist with time, your body is actually like a really long line (or tube) in spacetime. Each slice of you is a "moment of time", and it so happens that each moment can remember the previous moments, but not any of the following moments (this is ultimately due to another law of physics, the 2nd Law of Thermodynamics, which is what makes the future different from the past.)

5. I am not sure what contradiction you have in mind. Would you say that two different places have to be real in different senses? That two different people have to be real in two different senses?

From God's perspective, there is no such thing as the "past" or "future" since these are labelled by human beings relative to their current moment of time. So it is not true that past things exist in a different sense than present or future things. But it IS true that they exist as different moments of time. For example, 2008 is not the same year as 1993, they exist as two separate entities about which different things may be asserted.

6. Not sure if I can help you or not, but I would think of it like this. All of your moments of time are equally real, but each of them remembers the previous one most vividly and the selections from the past ones less vividly, and anticipates the immediate future. The brain takes a little while to process sense perception, so what you consider to be the present is really some finite period of time--a fraction of a second. These facts, together with [things about neurology and consciousness we don't understand] makes it feel as though time is flowing.

7. Your worldline has to go forwards in time, but can wiggle around in the 3 space directions (as long as you don't go faster than light). So yes.

8. If we talk about points of spacetime, then yes, Boston in 2008 is really a different location from Boston in 1993 since they differ in their times. So you never return to the same point of spacetime more than once.

9. You'll have to tell me what "seems" to be the case to you, but if B-theory is correct then B-theory must also seem correct to God (because he is omnisicent).

30. Angela says:

Hi Dr. Wall.
Firstly, let me say what a blessing and encouragement your site has been for me.
I am currently hung up on divine simplicity and time. I thought it was making more sense and then I read this article from Biologos :http://biologos.org/blogs/archive/questions-on-time-and-eternity-part-2
Must we assume that God and the universe are coeternal on the B Theory? That feels wrong.
Thank you for your illuminating insights.

31. Mactoul says:

Aron,
Regarding the relative merits of A and B theory of time, it seems to me only a matter of metaphor. The block universe replaces the temporal flow by spatial extension.
The question itself, Does past exist? needs to be addressed in the equivocal sense of the word "exist".
Time does not exist in the same sense as do the ordinary objects such as a table.

32. Aron Wall says:

Angela,
Can you say more about what "feels wrong"? I suppose the issue here is that "eternity" feels like a divine attribute, while on the B theory every moment of time would be in a sense "eternal" because it exists in an unrestricted sense and does not "pass out of existence" in the sense postulated by the A theory.

But I would say, even on the B theory, each part of the universe is limited and finite and exists in a particular moment of spacetime history, whereas God is equally present in all times. There is still a radical distinction between the unconditioned, unlimited, and necessary Creator, and the created things which are conditioned, limited, contingent. Thus God is eternal in the sense that he is timeless, and he is also eternal in the sense that he is fully present to whatever times happen to exist. Whereas the universe is a collection of things most of which are present at only some momennts of time.

Mactoul,
Even if Time does not "exist" in exactly the same (univocal) sense that a table does, it seems like the word "exists" is being used in at least an analogous sense (to appropriate a famous medieval distinction). It is not a merely equivocal use of the word "exists", which would be a completely separate meaning with no relation, like "bat" meaning a winged mammal and "bat" meaning a club used to hit a baseball.

However, I would say that one of the lessons of General Relativity is that Time does seem to exist phyiscally, using a similar definition of "exists" as we would use for the electromagentic field.

But I agree with you that the "block universe" is an excessively metaphorical way of speaking. That is why I avoid using this metaphor when talking about the B model of time. The "block universe" seems to presuppose A theoretic ways of thinking, and then asks one to imagine spacetime as an unchanging object. But it is not as though there is a second time dimension, with respect to which the 4d spacetime universe is failing to change.

33. Angela says:

I think what feels wrong is that it, to me, (at least at first blush) makes the universe feel necessary. Would a reply be that God is necessary and what He "knows" (the earth, people's lives, etc...) is necessarily true but secondarily? Meaning, from outside/before creation He could have known it to be diffrent therefore it is still contingent? And on that note, is there a "before creation?" I apologize if I'm not expressing this well, they are Very weighty thoughts for me.
Thank you.

34. David says:

I personally think that there is something to be said for the Scholastic theory of time. It may be summed up thus: change is an objective reality. In any concrete instance of change, "before" and "after" are also objective realities. But time is a product of a conscious being assigning numbers to before and after on the basis of certain cyclical changes (the orbits of heavenly bodies, the vibration of a certain kind of atom). It allows that "now" is, like "here," subjective, which it shares with B-theory. However, along with A-theory, it admits that succession, motion, and change are not illusory. Indeed, while "now" seems, as you say, subjective and reliant on an act of mental synthesis, it seems to me that the reality of succession and change in our mental states is equally undeniable.

35. Aron Wall says:

Angela,
I think even on the B theory one can assert that the universe is contingent and need not have existed. I don't see why it is inconsistent to say that something "might not have existed", even if it always exists.

I would say that:

* It is necessary that (if God knows we exist, then we exist)

is true but does not imply:

* if God knows we exist then (it is necessary that we exist)

Thus I would say that it is necessary that God knows what exists, but the fact that he knows *we in particular* exist was not necessary. (Since we might not have existed, and then he would have known that we didn't exist.)

If time was created by God, then there is no such thing, literally, as a "time before time was created". That is a contradiction. Nevertheless I think in a metaphorical way we can talk about "before Creation" as long as what we mean by that is that God's reality does not depend in any way on the existence of the Universe, so it is "prior to" (in the sense of "not dependent on") the Universe.

36. Duc Phan says:

Hi Aron,

I'm fascinated by your analysis of time. At first reaction, it seems so counter-intuitive because like a lot of the comments here, I 'feel' the flow of time. I'm still trying to wrap my head around all this and I'll be probably re-reading this article 100 more times. To be honest I went through all the comments and your reply to them as well and I have to say, MY MIND IS BLOWN!

Question:

1. What does it even mean to say God is timeless? Is He not Himself inside the slice of time and that ALL moments of Himself is 'out there' already so to speak? I can't, for the life of me, see how God's eternality is different from ours according to the B-theory of time since all the moments of ourselves are 'out there' as well. What does it even mean to say God created time?

2. If all moments are out there so to speak, would you concede that we are eternal with God? There isn't really a moment of creation (our 'creation' just means we are contingent to Him and doesn't really refer to a 'time' when we were brought into existence since we already existed because 'all moments' are out there already so to speak.).

3. If we are eternal with God in the sense that I refer to in 2, what can we say about unrepentant sinners? Why would God 'create' people who suffers for eternity and that ALL the moments of their sufferings are out there already... It just 'seems' to me that on the B theory of time there is predestination and God seems to make 'objects of wrath' so to speak.

37. Aron Wall says:

1. If God is timeless than he doesn't HAVE moments. Or if you prefer, God's existence consists of just a "single" moment, but rather than being an infinitesimal sliver of consciousness like our own moments (which is why they seem to "slip away" as soon as we have them), it contains the fullness of all his glory and wisdom. It is, in fact, Reality itself. He does not have a different version of himself at each moment, rather the SAME immutable divine nature is present at each moment of time. (Just as there is not one part of God here and one part in the Andromeda Galaxy, rather the fullness of God is present in all locations.)

This is a deduction from the fact that God is not only eternal but also simple, that is he has no parts.

2. Each moment of our existence does, in a sense, exist eternally in God's knowledge, since God always knows we exist. Yet our mode of existence is very different from that of God's in that (a) we are only present at some moments of time, not others, and (b) the version of ourselves at one moment is not the same as the version at another moment, we are always changing. Also we are contingent, not necessary beings.

3. I believe that God can eternally know that something is going to happen, and yet whether or not it happens was still a matter of free choice. God created the sinner with the ability to repent, and the fact that God knew he was not going to repent does not imply that he could not have. Had he chosen to repent, God would instead have always known he was going to repent. And this other timestream was fully possible, just not actual.

I am not a Molinist. That means, I do not think that generally there is a fact of the matter about what a nonexistent person would have done. So I think that God does have to actually create the person in order to "find out" whether they would repent or not. It's just, that God's knowledge is eternal, so if he does create the person than he always knows what they are going to do, and can take it into account in deciding what will happen in past ages (as long as he avoids time travel paradoxes, which I assume he is clever enough to do).

The word "predestination" is Scriptural, so all biblical theologies are required to accept some version of it! But it need not be given the exact same interpretation that Calvinists give to the word. The idea that God predestines us to glory is indeed a doctrine of comfort and joy for those who can take it on its own terms, without trying to construct a systematic theology that denies the equally biblical concept of free will. St. Paul says that predestination is based on God's foreknowledge: "For those God foreknew he also predestined to be conformed to the image of his Son" (Romans 8:29). We cannot understand life from God's eternal perspective, but we can take comfort in knowing that he does understand us from that perspective.

38. Michael says:

Hello Aron,

I want to ask you a question about the B-theory, specifically this statement of yours:

"The B-theorist would not say that all of time is literally now anymore than we would say that all places are here."

Under my understanding of the view, I am confused by this. I think I would have to side with your commenter on this one as it seems to me that the B-theory does entail that "all times literally exist now" provided one clarifies what we mean by a "time". According to the B-theory, there is no such thing as a passage of time, and thus nothing "will happen" or "did happen", so it seems to me like the logical result would be to say that everything is currently happening or is "present". Maybe I am wrong, but wouldn't that mean that every time exists right now?

The way I've interpreted the block universe of the B-theory is as a static series of 3 dimensional universes spread out in a fourth dimension that functions like space (which we would call "time"). Every time refers to just one of these slices, and how they are ordered within this fourth dimension determines what is "earlier" and "later". People like Socrates exist in one of these times, while we would find the 2020 Olympics happening in another of these times. If we were to look at the time dimension of the B-theory as essentially a fourth dimension of space (though not exactly the same as a dimension of space) where events can be said to be located, then there seems to be no problem in saying that they all literally exist now in the way that we normally mean it.

At least, that is how I essentially see it. Would you agree with this way of looking at things or is there something substantially different in the way you interpret the B-theory?

39. Scott Church says:

@Michael,

Part of the difficulty we face in trying to wrap our minds around B-theory time is that as spacetime-bound creatures in a universe governed by the Second Law of thermodynamics, our entire experience of time is asymmetrical. The future is unknown to us, the past is in our memories--we only directly apprehend our experiences here and now. That asymmetry gives us a fundamental sense of time as flowing and makes it exceedingly difficult for us to even speak of it, much visualize it, in any other terms.

It's one thing to say that all times exist, in the sense of being equally real. It's another thing altogether to say that "all times literally exist now". That statement isn't merely wrong--it's a misuse of language. The words here and now refer to our directly apprehended experiences of the present moment at whatever location we happen to be at. As I type this, I am in the Issaquah Highlands neighborhood about 20 minutes or so east of downtown Seattle. For me, here and now means Issaquah, WA at 4:10pm PST on Nov. 5, 2017. To say that all times literally exist "now", is no different than saying all places are "here"--that Issaquah, WA on Nov. 5, 2017 at 4:10pm PST is Kampala, Uganda on June 5, 1865 at 12 noon GMT. That's absurd. This is not what the words "here" and "now" mean.

A-theorists like William Lane Craig maintain that "here", "there", and "everywhere" exist, but only in what we directly experience as now at any of those locations. June 5, 1865, is no longer real and June 5, 2050, isn't yet. By contrast, B-theory doesn't state that all times are "now", or that the passage of time isn't real. It says that in a relativistic spacetime, those dates and times are no less real than Nov. 5, 2017 at 2:40pm PST, any more than Kampala, Uganda is less real than Issaquah, WA, and the passage of time--the present moment "flowing" from past to future--is a consequence of how we, as physically embodied creatures, experience the Second Law.

Beyond that, your interpretation of B-theory as "a static series of 3 dimensional universes spread out in a fourth dimension that functions like space" is essentially correct, but with a couple qualifications. First, to be precise, it isn't time $t$ that functions like space per se, but $-ct$, where $c$ is the speed of light, and the minus sign reflects the fact that per special relativity, time has a different metric signature than space. Second, the $-c$ part of that isn't just mathematical hair-splitting. One consequence of $x^{i}$ and $ct$ having different metric signatures is that the spacio-temporal "slices" you refer to are frame-dependent. If I'm reading you right, your description of a B-theory universe is similar to a layer cake in which successive layers of spatial "cake" are stacked temporally from bottom to top, with time being the vertical layer of ordering. In reality, however, for any two reference frames, that cake will be sliced diagonally as well as vertically depending on their relative state of motion, blurring the difference between your horizontal ("spatial") and vertical ("temporal") layers. Aron has a diagram here that shows how two observers, "Static Sue" and "Mobile Martha" experience the same two events $p$ and $q$ in such a spaciotemporal cake. Notice that their relative motion blurs the distinction between those "3 dimensional universes" and the time by which they're ordered, and even renders the difference between past and future arbitrary. Now, this arbitrariness of past and future does only manifest itself for events that are space-like separated (i.e. - one cannot reach the other without traveling faster than the speed of light). As such, for every event on any given world line, there is a realm of "absolute" past and future (defined by the past and future light cones attached to it), and it is possible to make A-theory work within a relativistic framework. But to most physicists doing so creates far more messes than it cleans up. How exactly does one make a horizontally sliced cake more foundational than one sliced diagonally? A-theorists need to demonstrate that Static Sue's reference frame is somehow more privileged than Mobil Martha's within a relativistic framework that gives us no formal reason whatsoever to prefer one reference frame over another, and make it more compelling than 100+ years of general and special relativity. That is a damn tall order. :-)

Best.

40. Michael says:

@Scott Church

Thank you for the reply. It seems like our interpretations of the B-theory overlap by and large, and I suspect that our disagreements may only be based upon words without substance. We all (you, Aron and I) may have the same idea on what we understand the B-theory to entail, but just describe it differently. That said, I still want to look at the source of our disagreement, and see if we can come to a common understanding.

"It's one thing to say that all times exist, in the sense of being equally real. It's another thing altogether to say that "all times literally exist now". That statement isn't merely wrong--it's a misuse of language."

Can you clarify the difference between the two? If a B-theorist says that all times are real and that they all exist equally, what would it mean other than to say that they currently exist? To me it cannot mean that they all times will exist or that they all had existed, as that (1) involves a passage of time, which a B-theorist is sure to reject and (2) seems to mean that they aren't real in the way they seem to intend. The only other logical option seems to be that they are all currently or presently real.

You talk about the common usage of the word "now", but I am not sure if that is even appropriate for our discussion. Note that the common use of the word "now", the way we define the term, is usually made in the context of A-theoretic views like presentism, where only one time is said to be real. However, here we are speaking of a view that is anything but common sense, as you have pointed out. We are speaking of a model where multiple times are said to exist in a real way together, in the same way that multiple places are said to be real together. I am not sure whether that is important, but I just want to point that out, since it seems like it may lead to confusion down the road.

41. Mactoul says:

Michael,
"all times literally exist now"

Time is not the kind of thing that can be said to exist simply. It is the things such as this table, this apple, that man--that can be said to exist simply and to exist in time.
This B-theory rests largely on linguistic confusion. It merely replaces the picture of time flowing into a spatial picture but as you see it is hard to get rid of the temporal words. You can't avoid using words such as "now", "currently" etc.

It is better to adopt simpler, commonsensical language in which past things existed in past, present things exist now, and future things do not exist yet or will exist in future.

42. Michael says:

@Mactoul

"Time is not the kind of thing that can be said to exist simply. It is the things such as this table, this apple, that man--that can be said to exist simply and to exist in time."

I grant that there is a certain amount of confusion that can come with saying that "All times exist now", particularly if we try to look at those times as including the "past" and "future". Not sure if anybody caught on, but there is a contradictory way in which one could read the above phrase, one that suggests that "non-present times are present", which is simply false. But I this is just the result of us applying our traditional understanding of time on a non-traditional view. Of course the language would be confusing. But that doesn't mean that the statement is really contradictory.

Instead of speaking of "times" existing or the "past and future", it would be less problematic to just focus on the contents of those times existing. For instance, instead of saying "Socrates exists in the past and the past is now real", we just say "Socrates is now real", effectively cutting out the middleman. So far as I see it, saying "Socrates is currently existing" is less problematic than saying "the past is currently existing". One is contradictory, the other isn't. So Socrates exists, and so does the 2020 Olympics, in the same way as your apple, or your table. Of course we do categorize them into their own 3D universes which we can refer to as "times" but that is after the fact.

"This B-theory rests largely on linguistic confusion. It merely replaces the picture of time flowing into a spatial picture but as you see it is hard to get rid of the temporal words. You can't avoid using words such as "now", "currently" etc."

I agree that there may be some verbal confusion going on here, which is what I am trying to address. There are those who argue that the debate between the A and B-theory rests upon a verbal dispute, and that there is no substantial disagreement between them. I probably wouldn't go that far, since I do think that there is a substantive disagreement between all views the views in times, including the Growing Block view (in the way I interpret it), but I think that this requires that they accept tensed language, at least to a certain degree when speaking about what is "real".

43. Christopher says:

", and it is possible to make A-theory work within a relativistic framework" What attempts do you think are the most interesting and what problems do they raise exactly? I am studying the A-theory B-theory debate right now and would love to hear what sort of attempts you have seen and where you think they fall short.

44. howie says:

When LIGO made its discovery last year . Bill Craig made the comment: "
"In the application of the General Theory of Relativity to cosmology, there emerges a cosmic time which is a parameter that is independent of spatial coordinates and so is the same for all observers in the universe, regardless of their motion. When cosmologists say that the universe is 13.8 billion years old, they do not mean merely in Earth’s time; rather they are speaking of this cosmic time which is the same for all observers and measures the proper time of the universe since its inception. The existence of such cosmic time is right in line with Lorentz’s view and represents in a real sense the resurrection of absolute time."

Is he right about this? I have spoken to several physicists who understand CMB physics very well and they all say there is no absolute time. Could you comment on this?

45. Mactoul says:

Michael,
<>

In what sense of the words "currently" and "existing", it is true that "Socrates is currently existing"?
As I see it, the sentence is false though logically not self-contradictory.

46. Mactoul says:

Michael,
Why do the physicists talk about "all times (past, present, and future) exist equally" or "not exist"?
I think this may be traced to the abstraction that is made in relativistic physics. Physics seeks to describe behavior of changes in things--such as this chair, this apple etc. But they introduce abstractions such as spacetime filled with mass-energy. Thus, it is easy to lose sight of the discreteness of the things themselves and then it is an easy step to talk about "time existing" or "moments existing" .
Thus, faced with grandiose and counter-intuitive claims, it is necessary to step back. Spacetime is an abstraction, it doesn't exist in the same sense as ordinary things exist.

47. Michael says:

@Mactoul

"In what sense of the words "currently" and "existing", it is true that "Socrates is currently existing"?"

In what sense do you think a table"currently exists"? Or an apple? I'm not trying to be sneaky in my use of "currently exists". Somewhere, right now, a table exists. And similarly somewhere, right now, an old man who is a philosopher by the name of Socrates exists. As for where, exactly? That is another issue.

"As I see it, the sentence is false though logically not self-contradictory."

Good, my point was that the statement is not contradictory or simply false on its head. Whether you believe that the statement is true though, depends upon your position on time.

I think every view on time can be distinguished based upon (1) What currently exists and (2) Whether there is a flow of time that changes. Presentists (A-theorists) would, under my interpretation, say that what currently exists is limited to a single 3D state of the universe, an instantaneous moment, and that things do flow. Eternalists (B-theorists) would say that what currently exists is a series of 3D slices in a 4D block representing the history of the entire universe, but reject the flow of time so that there is no change in this fact (hence they can be said to be "eternal"). I'll leave it to you to guess what views like the Growing Block entail.

"Why do the physicists talk about "all times (past, present, and future) exist equally" or "not exist"?"

You mean why do they believe in the block universe? Most of the support for the view I think comes primarily from thoughts about relativity. According to the view, our views about what events are simultaneous (which is what we use to determine what exists now) can vary depending upon your motion. Because there is no way to determine which frame of motion is privileged (an idea dating as far back as Galileo it seems), we conclude that there is no absolute sense of simultaneity and trying to limit existence to this is simply wrong headed. It is often considered a "deal breaker" to views like the A-theory, as it can be construed as a case of "Science vs. Philosophy", but I think that it is overblown to an extent. Of course one can simply assume that there is an absolute sense of simultaneity, which would be compatible with the models so far. However, this is often seen as ad hoc given that it is unobservable, though if people have philosophical reasons for believing in it, then that could be surmounted IMO. In the end it is still a blow to the view, but not an absolute "deal breaker".

48. Mactoul says:

Michael,
"somewhere, right now, an old man who is a philosopher by the name of Socrates exists"

This illustrates the point made by Dorothy Sayers that the B-theory merely uses spatial metaphor to replace the temporal.
Additionally, your sentence "Somewhere, right now, a table exists" doesn't adequately translate the sentence "this particular table exists now". Also, considerable precision is lost and for what gain?

My own view on the popularity of B-theory is that it is an instance of training in "objectivity" in the sense of That Hideous Strength by CS Lewis---elimination of all specific human attitudes and reactions. Curiously, some classical theists have jumped on the bandwagon, beguiled perhaps by the name "eternalism", but they fail to realize that since classical theism derives an eternal God starting from changes in ordinary things, they are cutting the tree they want to stand upon if they start casting doubts on changes in things themselves. No change, no simple and eternal God of classical theism.

49. Mactoul says:

Michael,
"Presentists (A-theorists) would, under my interpretation, say that what currently exists is limited to a single 3D state of the universe, an instantaneous moment"

I would again recommend talking about existence of particular things and not abstraction such as "state of the universe".
This chair exists now. But its existence is not limited to existence in a single instant of time but implies endurance over some time. The word "now" packs a lot of meaning and so does the word "chair". That enlarged perspective takes care of any problem with relativity.

PS The point about Socrates was in reference to your
"instead of saying "Socrates exists in the past and the past is now real", we just say "Socrates is now real"

50. Scott Church says:

@Michael,

I do suspect that, as you say, your understanding of B-theory does for the most part overlap mine and Aron's, but there definitely is some linguistic confusion going on here. If a B-theorist says that all times are real and that they all exist equally, what, you ask, would it mean other than to say that they currently exist? The problem with that question is with the word currently. Let's return to Aron's figure depicting how Static Sue and Mobile Martha experience spacetime. Current... present... now... These words only have meaning for specific events like $p$ and $q$. They have no meaning for spacetime in general, as represented by that entire figure. To say that "all [times are] currently or presently real" is like referring to all space with the statement that "everywhere is here". Again, this is not what the words "here," "there," "now," and "then" mean.

Nor is the difference between the two theories just semantic. A-theory maintains that the physical universe exists only in the immediate present. For the reasons I outlined in my last, the Riemannian structure of spacetime and the different metric signature of $x^{i}$ and $ct$ make that very difficult to defend because from the standpoint of physics, there is no unique frame-independent way to distinguish here and now from "there and then", and as such, no way to make our experience of it more objectively real than it is in any other frame without some serious hand-waving. We can debate whether all times other than the present exist if we like, and as such, whether our experience of the present as "flowing" from the past and into the future is real or in our perception. But words like "now," "currently," or any of their synonyms are only meaningful in the context of A-theory. They don't belong in any discussions of B-theory.

@Christopher,

The gory details of how A-theory's advocates make it "work" are more than can be done justice in a single comment. But suffice to say that typically they do so by attempts to specify some sort of preferred reference frame with which an objectively real "present" can be identified, and then relegate all the problematic frame-dependent consequences of the Lorentz boost to realms outside of the past and future light cones of all spatial locations, and thus beyond our experience. For a more thorough look at these gory details, I'd recommend Craig's book Time and Eternity, or Creation out of Nothing which he co-authored with Paul Copan. For more on what's wrong with it I'd re-read this essay of Aron's again, and check out Part I and Part II of this series.

@Howie,

The "cosmic time" Craig is referring to is that of a reference frame that is stationary with respect to the expansion of the universe. It must be remembered that that expansion is not one of matter rushing outward from some central "explosion," but an expansion of spacetime itself. Length, breadth, and height, so to speak, are expanding, and the matter they contain is along for the ride. One of the consequences of this is that because it is the underlying manifold itself that's expanding, observers in a reference frame attached to any point in space will see themselves as stationary, and every other point receding from them radially at speeds that vary linearly with their distance of separation. The further they are away, the faster they're receding from the stationary observer. This is not unlike blowing up a polka-dotted balloon. As the balloon inflates, it will stretch evenly in every direction at every point. Every polka-dot will see itself as the center of the inflating balloon surface, and polka-dots that are $x$ times are far away will be rushing away from it $x$ times as fast. Any reference frame that piggy-backs on the expansion of the universe like this is said to be comoving, and because all such frames experience the same history of the universe's expansion, they share a common proper time. This is the "cosmic" reference frame Craig and other A-theorists speak of.

However, this comoving frame is "cosmic" only in the sense that it's the same for any point riding on the surface of the universe's expansion. Beyond that, the physicists you spoke with are right--from the standpoint of special and general relativity, it isn't absolute at all. Observers in a reference frame moving with respect to the earth, or any other such comoving frame of reference would experience time and space very differently per the Lorentz boost. From the standpoint of A-theory, a comoving reference frame is certainly the most logical choice for one on which an absolute "now" might be grounded. But beyond that, it does little to make A-theory formally simpler and more to the point than B-theory.

Best to all three of you. :-)

51. Michael says:

@Scott Church

" These words only have meaning for specific events like pp and qq. They have no meaning for spacetime in general, as represented by that entire figure. To say that "all [times are] currently or presently real" is like referring to all space with the statement that "everywhere is here". Again, this is not what the words "here," "there," "now," and "then" mean."

It seems like you're reading "all times are currently real" to mean something like "all times are real at Nov. 2017" or "all times exist in a single 3D timeslice". My interpretation of the B-theory does not say this. The different events are separated in their own separate 3D spatial universes, which represent the world at Nov. 2017, and other times like 400 BC. There is a temporal distinction here, and they all exist at their own "temporal location" (which refers to the 3D slice they occupy). However, I have no trouble referring to all of them as existing now. If it helps, you can also refer to this block universe as a multiverse composed of a 4D set of 3D spaces. In a sense, that is what it is, a series of parallel realities structured in a specific way. Hopefully, it should make it easier to understand how they can all currently exist, as most of us (at least, I do) find no trouble in speaking of a multiverse existing literally now as a whole.

"If a B-theorist says that all times are real and that they all exist equally, what, you ask, would it mean other than to say that they currently exist? "

I am not sure you addressed my concern that I raised earlier. I pointed out three senses of "exists", which I believe to be exhaustive. Either something is, was, or did exist. The B-theorist wants to say that all times are real and that they all exist equally. What exactly does that mean, and how is that different from saying that they all exist now? If something neither does currently exist, did exist, nor will exist, then what else is there?

52. Scott Church says:

@Michael,

I'm reading it that way because "all times are currently real" does mean "all times are real at Nov. 2017." As I type these words, current, present, and now all do, in fact, refer to Nov. 2017--which is precisely why they don't belong in any discussion of B-theory time. Furthermore, neither your "temporal locations" nor the "3D [slices] they occupy" exist in any objective non-frame dependent way.

Go back and have another look at how Static Sue and Mobile Martha experience events $p$ and $q$. At $t = 0$ the 3D spatial universe that defines Static Sue's "now" is the gray $t = 0$ axis. As long as she doesn't move, the vertical black line which is the time axis in her reference frame defines her static location in that universe. But at the same time, Mobile Martha's "now" is the light red $t' = 0$ axis, and although the figure doesn't show it, her time axis and stationary location would be given by another light red axis tipped clockwise to the right from Static Sue's vertical black one. Thus, in this diagram, Mobile Martha's time and space coordinates form a light red parallelogram with respect to Static Sue's square one.

Notice that what for Mobile Martha is one of your 3D static universes at "now", is for Static Sue a moving surface that has a time component as well as a spatial one, and her stationary time component has a spatial dimension in Static Sue's reference frame as well. In other words, for Static Sue, Mobile Martha's "3D slices" have a time component, and her evolving "nows" have a spatial one. Not only does this blur the distinction between space and time, it blurs the difference between past and future as well.

For static Sue, if $p$ occurs now, at say, midnight, Nov. 1, 2017 (time $t = 1$ in this figure), and $q$ happens later, at around 3am, Nov. 1, 2017 (if $t$ is calibrated in days). But in Mobile Martha's reference frame, midnight, Nov. 1, 2017 is at $t' = 1$, $p$ occurs later that afternoon, and $q$ has already occurred and is in the past. Thus, for Static Sue $p$ now exists and $q$ will exist, but for Mobile Martha (t' = 1) $p$ will exist and $q$ did exist. In both cases we're talking about the same two events $p$ and $q$. The difference in how space and time slice themselves up for each of them is due only to the fact that Martha is moving with respect to Sue. Furthermore,, the exact same figure could be drawn from Martha's reference frame, in which case she would be static and Sue would be mobile.

The bottom line is that there's no such thing as space and time--only spacetime--which depending on whether one is static or moving with respect to someone else, can be sliced an infinite number of ways yielding different 3D spatial slices and times.

What exactly does it mean, you ask, to say that all times exist equally? It means that $p$ and $q$ are both equally real, but at midnight, Nov. 1, 2017, $p$ now exists for Static Sue and $q$ will exist, and for Mobile Martha $p$ did exist and $q$ will exist. Neither of these can be said to be any more real than the other, any more than one could state that a car driving down a highway through a forest is moving and the trees he's passing are stationary, or the driver is stationary in the front seat and the trees are moving past him. The trees are no less real in either case. The only difference in perception is whether one defines "stationary" with a coordinate system attached to the car, or one attached to the roadside.

What the A-theorist must do, is demonstrate that Static Sue's reference frame (or Mobile Martha's for that matter) is somehow more real than any other--that is, that a coordinate system attached to the driver in the car is a less ambiguous and more absolute definition of 3D spatial slices and times than one defined at the roadside, and that the trees don't exist before, or after, they've passed out of his field of vision. If that makes more sense to you, then more power to you. But to me, and to Aron and the physics community, it's a damn tall order. :-)

53. Michael says:

@Scott Church

"I'm reading it that way because "all times are currently real" does mean "all times are real at Nov. 2017." As I type these words, current, present, and now all do, in fact, refer to Nov. 2017--which is precisely why they don't belong in any discussion of B-theory time. Furthermore, neither your "temporal locations" nor the "3D [slices] they occupy" exist in any objective non-frame dependent way."

You read it that way, but that is not what I am saying. Again, I must stress that I do not say that all times are "currently real" in the sense that you've given, as existing within a single 3D timeslice. Indeed, the fact that I am referring to the events of the block universe as existing in a 4D structure already precludes all times from being captured by a 3D slice of this structure (no matter which way you happen to slice it). Whether you define Nov. 2017 according to Mobile Martha or Static Sue, not all times are captured by it.

"What exactly does it mean, you ask, to say that all times exist equally? It means that p and q are both equally real, but at midnight, Nov. 1, 2017, p now exists for Static Sue and q will exist, and for Mobile Martha p did exist and q will exist. Neither of these can be said to be any more real than the other, any more than one could state that a car driving down a highway through a forest is moving and the trees he's passing are stationary, or the driver is stationary in the front seat and the trees are moving past him. The trees are no less real in either case. The only difference in perception is whether one defines "stationary" with a coordinate system attached to the car, or one attached to the roadside."

You missed the part where I also referred to the fact that the B-theorist also says that all times "exist". Supposedly they are there, in reality, somewhere, and exist in a concrete sense that we wouldn't attribute to characters like Santa Claus and the Tooth Fairy. I took it as meaning that it currently exists (as that seems to be the only way for me to make sense of it), but you disagreed, which is what I am still trying to understand. So in what sense are they said to all "exist" then under the B-theory?

54. Mactoul says:

"The B-theory (a.k.a. eternalism) claims that all times (past, present, and future) exist equally,"

I am not understanding why it is necessary to claim that either only present time (or present things exist)
or all times exist. Why is this way of speaking not possible in which a thing A is in state S1 at time t1 and in state S2 at another later time t2.
The thing A was existing at t1 and and t2. It did not go out of existence at t1.

Nothing was going out of existence or ceasing to exist. The A-theory language used here "neither the past and future really exist, but only the present moment is real." is misleading strawman, encouraged by certain philosophers as an exercise in "objectivity".

55. Mactoul says:

This excerpt from Edward Feser's blog, quoting the philosopher of physics Tim Maudlin:

"[M]any physicists and philosophers like to say that the passage of time is an “illusion”. In my account of things, it is not at all illusory: time passes from past to future by its intrinsic nature. Further, the fundamental laws of nature are exactly physical constraints on what sorts of later states can come from earlier states. Parmenides, of course, also argued that time and motion are illusions. I think I understand what he was claiming, and think it is just flatly false. I don’t see the modern defenders of the “illusion” claim as in any better position than Parmenides was.

I further believe that physicists have been misled by the mathematical language they use to represent the physical world. Temporal structure is part of (maybe all of!) the geometry of space-time, and the standard mathematical description of geometrical structure was developed with purely spatial structure in view. Space, unlike time, has no directionality and the mathematics developed to describe spatial geometry does not easily or naturally represent directionality. "

I’ve made points like these myself and their importance cannot be overstated. ... a Parmenidean interpretation of relativity is ultimately incoherent; and much fallacious thinking about the implications of physics rests on a tendency to mistake its mathematical representations of the physical world for an exhaustive description of that world. (That physicists have been misled by their mathematical models into denying the reality of time is also a theme of physicist Lee Smolin’s new book Time Reborn.

56. Michael says:

@Scott Church

"What exactly does it mean, you ask, to say that all times exist equally? It means that p and q are both equally real, but at midnight, Nov. 1, 2017, p now exists for Static Sue and q will exist, and for Mobile Martha p did exist and q will exist. Neither of these can be said to be any more real than the other, any more than one could state that a car driving down a highway through a forest is moving and the trees he's passing are stationary, or the driver is stationary in the front seat and the trees are moving past him. The trees are no less real in either case. The only difference in perception is whether one defines "stationary" with a coordinate system attached to the car, or one attached to the roadside."

Okay, I tried to spend some time understanding this, but as is I just can't make sense of it. The way I see it, this seems to suggest that according to Sue, p exists, and according to Martha, p does not exist. So to one, p is a part of reality, and on the other it is not, and there is nothing that could allow us to prefer one story over the other. So what is the status of p then? Does p actually exist or does it not? What about us? Is there an objective fact as to whether or not we exist? If I follow your reasoning then the answer seems to be that there is no absolute fact of the matter. Hmm.

Note that the same story can't be said for your trees. Both trees can be said to be real whether or not they are truly moving or not and, as you have pointed out, that fact has no relevance to it's reality at all. Not in the case of p and q however, where the reality of these events are actually what is at stake. If we are looking from Sue's perspective, p is certainly real, while according to Martha, p is not.

Now the reason why I read your statement in the above way is because traditionally, saying that something "will exist" or "did exist" is synonymous with saying that it is "past" and "future". To say that something "did exist" means that it ceased to exist and to say that it "will exist" means that it will come into existence. In both cases though, they don't exist in reality. They aren't actual.

The only way I can make sense of your statement is by replacing the "will exist" and "did exist" with earlier/later relations. So for example, according to Martha at t'=1, q is" earlier" than Nov. 1, 2017 and for Sue at t=1, q is "later" than Nov. 1, 2017. Applying this to my 4D spatial block model, I've taken this earlier/later relation to refer to a 4D spatial relation similar to how something is to the left/right, above/below, or behind/ahead of something else. According to relativity, Martha and Sue would slice up the 4D block universe in different ways and what events are earlier and later to their slice depend upon their motion. Of course, under this view, I take both p and q to be now real, so I am not sure if that's how you would want to read it.

57. Scott Church says:

Hello @Michael,

My apologies for the delay in responding! I started a new job just before Halloween and things have been a little hectic while I've been ramping up there.

You say you can't make sense of how $p$ can exist for Sue but not for Martha...? Yes Sir! You can't make sense of it because there is no sense to be made of it. If the only difference between how the two of them experience $p$ or $q$ is whether they're in motion relative to each other, how does one tie "absolute" reality to one of those reference frames but not the other? But the solution to this dilemma isn't to question the objective fact of $p$--it's to question the non-existence of the objective factuality of $p$ or $q$ in either reference frame.

One thing I could've made clearer in previous comments is that the slope of Mobile Martha's $x$ and $t$ axes with respect to Static Sue's is a function of the relative velocity of their reference frames. The faster Mobile Martha is moving, the steeper her light red $x$ axis is, and the shallower her $t$ axis is (that is, the greater its clockwise angle with respect to Static Sue's solid black $t$ axis). The parallelogram formed by her coordinates becomes flatter and flatter, and at the speed of light, the two axes converge in a single axis at a 45 deg. angle to Static Sue's (in coordinates that normalize $ict$ to $x^{i}$). Thus, at the speed of light time vanishes, and from a photon's perspective, its interactions with all emitters and absorbers are simultaneous. With that in mind, notice that if Mobile Martha is moving at just the right speed with respect to Static Sue, her $x$ axis will pass through both $p$ and $q$ and as such, $p$ will occur now for them both. However, while $q$ will be part of Mobile Martha's "now", it will be in Static Sue's the future. Furthermore, this isn't just a consequence of Mobile Martha's experience. From her static experience of her frame, she'll see the world the way Static Sue does in hers. The bottom line is that simultaneity is relative to one's reference frame and so is the temporal ordering of events. This makes it extremely difficult, if not impossible, to make sense of the claim that only $p$ is real, and $q$ isn't.

You say the only way you can make sense of my statements is by replacing "will exist" and "did exist" with earlier/later relations... Yes Sir! And therein lies of the essence of B-theory. Events like $p$ and $q$ are all real, but have different temporal relationships to each other depending on what coordinate system (i.e. - reference frame) one is using. In one $q$ is later than $p$, in another it's earlier, and in yet another the two are simultaneous. Phrases like "did exist" and "will exist" are based on our experience of $t$ as something that flows from the past and into the future. That, in turn, has more to do with how the Second Law of Thermodynamics impacts how we see the world than with the nature of spacetime itself.

@Mactoul refers to the views of Maudlin and Smolin that the B-theory view may be a consequence of the mathematical framework of physics rather than the actual nature of time itself as something that really does, in some sense, flow. Perhaps. I haven't read Smolin's book Time Reborn yet (Aron, have you?), and it does sound interesting. But today, if anything is foundational to our understanding of the physical world it's the constancy of the speed of light and the relativity of simultaneity. Indeed, this is why we refer to it as the theory of relativity. Reconciling these with an A-theory view of time is difficult, to say the least, and for the time being anyway, physics gives us little reason to.

Best. :-)

58. Michael says:

@Scott Church

No worries, I understand if you've been busy. I have to say that I appreciate your willingness to have a discussion with me and your patience thus far.

"You say you can't make sense of how p can exist for Sue but not for Martha...? Yes Sir! You can't make sense of it because there is no sense to be made of it. If the only difference between how the two of them experience p or q is whether they're in motion relative to each other, how does one tie "absolute" reality to one of those reference frames but not the other? But the solution to this dilemma isn't to question the objective fact of p--it's to question the non-existence of the objective factuality of p or q in either reference frame."

Well, what I actually said was that I can't make sense of how there can be no objective fact to p's existence. You exist in spacetime just as much as p does.. To Martha, you may exist, but to Sue you may not. Do you really exist? Well, there is no objective fact of the matter, and unless we are comfortable with talking about our status as schrodinger's cats, then I don't see how that can't be a wild conclusion.

My suggestion was to replace the "did exist", "will exist", and "now exists" with something like a spatial relation. In essence it is pretty much the diagram in Aron's Martha and Sue diagram, but blown to 4 dimensions. Instead of cutting a flat 2D surface with a 1D line, we are cutting a 4D spatial object with a 3D slice, and the manner in which you slice it would separate the parts of the object into an "earlier" and "later" part, depending upon which side of the slice it ended up on. And yes, the manner in which you slice it depends upon your velocity. What is "earlier" wasn't "past" and what is "later" isn't "future" in the sense that they "ceased to exist" or "will come into existence". Both are currently there, despite being located at different spatial locations.

"Thus, at the speed of light time vanishes, and from a photon's perspective, its interactions with all emitters and absorbers are simultaneous. "

Wait, I thought there is no such thing as a frame of reference for a photon, and in turn no such thing as a "photon's perspective". Such a reference frame is meaningless because everything that moves at c will move at c at all reference frames according to relativity. It is like talking about division by zero, and quite literally so, as if you use v=c for the formulas, you end up dividing by zero.

"You say the only way you can make sense of my statements is by replacing "will exist" and "did exist" with earlier/later relations... Yes Sir! And therein lies of the essence of B-theory. Events like p and q are all real, but have different temporal relationships to each other depending on what coordinate system (i.e. - reference frame) one is using."

If that is the case, then you would have no problem saying that p and q are both now real then, cause that's the way I see it. And not just that p and q are now "relative to Martha at Nov. 1, 2017" but in an objective sense. That is how I understand the idea that p and q are "real" but if you beg to differ then I want to know what you could mean when you say that all events are "real" under the B-theory. Are you sure that you are agreeing with me?

_____________

Now, it seems like the core of our disagreement stems from the manner in which you view the saying that things "currently exist". I would like to go back to an earlier quote made by you:

"I'm reading it that way because "all times are currently real" does mean "all times are real at Nov. 2017." As I type these words, current, present, and now all do, in fact, refer to Nov. 2017--which is precisely why they don't belong in any discussion of B-theory time. Furthermore, neither your "temporal locations" nor the "3D [slices] they occupy" exist in any objective non-frame dependent way."

You seem to equate what "currently exists" with a 3D timeslice or a single state of the universe. However, I believe that we can and should make a distinction between the two. We can speak of a 4D object existing now, and in addition we can speak of a scenario where multiple states of the universe's history are currently real, with one of those states representing the universe at Nov. 2017 (think of a multiverse, if you will). I see no reason why we should limit the definition of what "currently exists" and unless you understand that then I don't think I can make sense of your view.

Now, I think there is a reason why you define the "now" that way. If we were to look at the world in terms of an A-theorist presentist, then you would be absolutely correct in equating the "present" with a 3D state of the universe, because that is all that exists. Under the standard commonsense view, we understand the universe to be a series of 3D timeslices coming in and out of existence with the passage of time. We are so used to understanding what is currently real as only one state of the universe that we may choose to equate the two, but I believe this is mistaken. If we are going to talk about non-standard views of time like the B-theory, then we are certainly going to run into problems.

Let's start off with the normal A-theorist view of time, as a series of 3D moments coming in and out of existence. Obviously we treat the 3D moment that exists as "currently existing". Now, let's sever the flow of time from this picture. This means eliminating the future and the past. Nothing will happen, and nothing did happen. Nothing changes apart from what already is and all is static. There is only this 3D moment which is "currently real".

Now, let's expand the 3D moment into a 4D spatial object. Within this 4D object we find the 3D moment we started with, plus a set of other 3D moments representing different states of the universe. We can place these 3D moments in such a way that they can be ordered from earlier to later, and the manner in which they are ordered can vary depending upon how you choose to slice the 4D object. Now, in what sense are the moments in the 4D object real, you might ask? Well, they are all "currently real" as they were from the very beginning. That has not changed.

To me this is essentially the block universe of the eternalist. It is static; there is no flow of time, and no past and future to speak of. All the 3D moments are ordered from earlier to later, and they can be ordered in various ways. Finally, all events are real and exist in the same sense. They are all understood as literally now existing. The fact is, I do not see any substantial difference between this view and that of the eternalist. If you believe there is a difference, then I am open to hearing it.

Please note though that simply saying that the eternalist wouldn't say that "all events are now real" unlike the picture drawn above would not be satisfactory, as that is precisely what is at question. If you cannot give me a substantial difference as to how they are different, then I can only conclude that they are not.

59. Scott Church says:

Hello @Michael,

Having read through your last a few times, I don't see anything of real substance in it that I'd take issue with, and I suspect our "disagreements" are more quibblings over terminology than anything else--specifically, how we both use words like "now," "currently," and "exists." When I say these terms have no place in discussions of B-theory, I'm using them in the sense that most people do--as references to the world of our immediate experience, as opposed to what we perceive as having vanished into our past and not yet "arrived" from our future. You seem to be using them in a different sense involving "block" space and time, and if I'm understanding you correctly, I can see how from your perspective they work.

In discussions like these, I prefer to address the more common understanding of words like "now" and "currently" because this is what A-theorists are trying to preserve. According to A-theory, there is a preferred reference frame (typically taken to be a comoving "cosmic time" frame that scales with the expansion of the universe) in which the present moment physically exists, but past and future events do not. In this world, $p$ "emerges," so to speak, from the future and "disappears" into the past. $q$ does not exist at all until its world line "crosses" the $t = now$ axis in this preferred frame. It is this metaphysical view of time that's hard to reconcile with an extremely well-supported relativistic framework--the claim that the passing of time isn't just a matter of our perception (due to the Second Law), but an actual flowing moment where physical things come into existence in a particular reference frame and then vanish back into nothingness as the clock ticks. This is what most physicists find problematic.

As long as that difference is understood, the words we choose to make our points are themselves far less important than the content they convey. If our terminology shoes fit they can be worn, provided we're being clear and consistent with them. But that said, it's worth noting that as creatures whose experience of the world is inextricably bound to asymmetric time, where the past is something we remember and the future is unknown to us, it's extremely difficult for us to wrap our minds around time from an eternal "spacetime" standpoint. As such, it's all the more important to be clear about how we're using words like now and eternity when making our points.

Best. :-)

60. Michael says:

@Scott Church

It indeed seems like our disagreement is purely verbal. From what I can gather, your definition of "now" is more restrictive than the way I am using it, referring only to a single 3D state of our universe. I think I would argue though that the way I use the term is more in line with its traditional definition (even if that definition may not equate to how we are accustomed to using it). Whether you would agree with me on that front or not, that is neither here nor there for our discussion. Thanks for taking the time to talk with me, and allowing us to understand each other's views. Hope you have a happy Thanksgiving and best of luck on your new job.

61. igore says:

Greetings, As I see it, there is no such thing as time. Time is what we call that which is measured by a clock. A clock is a reference item that has a regular cycle or counting capability. The only meaning of "now" is that there exists a particular configuration of everything that exists. What we call the past is just previous configurations of everything that exists/existed. Any memory of the past is memory of those previous configurations. If we say that time exists, it is for only an item that is undergoing change. If there could be an item that was not undergoing change in any way, that item could be described as timeless - changeless would imply timeless. Time is not a substance/force/entity and does not infiltrate or permeate anything. To describe something as "not part of time" seems to suggest timeless. So this something would be "frozen" and changeless. Changeless implies inability to be active in any way - so no creation, no prayer answering, no miracles. I know that this is a lot to take in, but hopefully it is consistent and makes no demands of magic. rgds.

62. James says:

I liked where you were heading but then you hung u turn :)
You're also interpreting the A with the B.

This is a problem caused by words not reality or data. Statements like "that means the future doesn't exist" and so on are Asserted as symptoms of a disease that doesn't exist.

People seem to get wrapped up in this terminology that they've convinced themselves they have some epic significance.

Time flowing..... It's like everyone's gone mad.
Matter & Energy are in motion in Space that's also is in motion. That movement, including the motion of electrical impulses in the brain, is simply happening.

There's no dilemma here. Just because nerds talk of *past & * future as if they are scientific entities doesn't mean that they are anything more than words in a dictionary used to orient our lives.
Objective temporal becoming is as obvious as you reading each word you now see and if you happen to be in motion, than the atoms are in motion along with you in relation to atoms here in my home.

People who talk themselves into a frozen universe where nothing ever happened, lack space on their blackboard to fit all the complete absurdities that encompass that idea. We stand in relation to objects & thoughts in motion. The nerds who don't want free will, God, or a creation event push the Block universe for the same reason they do multiverse. So just remember that pathological bias is involved in a lot of the assertions coming from these ideas.

63. Aron Wall says:

James,
I agree that it feels as if time is flowing. But it also looks like objects that are farther away from me are smaller.

In constructing an objective view of the world, I discount the latter illusion as an being an artifact of my perception. So it doesn't seem impossible that I can discount the former sensation as an illusion as well.

I also agree that I am "interpreting the A with the B", as you put it, but that is because when I interpret the A-theory about time flowing in term of A-theory itself, I seem to lead to an infinite regress that prevents me from actually making sens eof the the A-theory. That was one of the main points of the post above.

64. Boltzmann says:

What if one claimed that energy is eternal , and so no God is needed .

65. GW says:

Not sure if this is the right post for this, but I was wondering if you could provide some commentary on the following article and perhaps these papers I and II. The physics seems, to my untrained eye, solid (or at least peer reviewed!) but the philosophical conclusions (the authors suggest a "free will outside space-time") less so.

To my knowledge the experiments add nothing particularly new to the relativity/quantum discussion. We're still where we've been: quantum mechanics and relativity seem to be incommensurate and so off we go in string theory, loop quantum gravity, fecund universes, etc.

What is interesting (and why I'm responding to this particular post, though I suppose the others that are more science-oriented would do fine) is the experiments seem to suggest that quantum mechanics at least supports the B theory of time if not empirically confirms it (whatever that may mean).

As an aside, does the B theory of time render theodicy impossible? Not only is there suffering in the world, but all suffering exists forever.

66. Aron Wall says:

GW,
One of your links seems to be broken; at least it didn't work for me.

The Atlantic article talks about an experiment which failed to measure a deviation from QM, so that shouldn't change anything about how we interpret it, right?

"Peer reviewed" is not even remotely close to a synyonym for "solid". Peer review as actually applied is more like a spam filter, than a quality check!

As an aside, does the B theory of time render theodicy impossible? Not only is there suffering in the world, but all suffering exists forever.

If "exists forever" means "is prolonged for all eternity" then this does NOT in fact follow from the B theory, since that isn't what B-theorists mean by eternity. In particular, it is compatible with the B theory to say that all suffering is confined to a finite volume of spacetime.

Let's make an analogy to space. Even A-theorists usually believe that things happening in different spatial positions are equally "real" (as long as they are at the same time). Now suppose that today I have a headache in the United Kingdom (not actually true, but pretend it is). "Aron Wall has a headache in the United Kingdom" is then a true proposition in Australia, and indeed in the entire universe, but the fact that it is a true proposition everywhere doesn't make my headache in any way worse, does it? Similarly, I think that on the B-theory, I still suffer the exact same amount that I would in the A-theory.

In any case, it is not suffering per se, but rather unjustified suffering, which causes a problem for theodicy. On the B-theory, it is also an eternal fact that our sufferings are joined together with Christ on the Cross, who provided "atonement" for all the suffering and evil that occurs in the world, by somehow incorporating that suffering into God's own experience, and thereby transmuting it into glory.

Dr. Wall,

I am a 25 year old agnostic and I really enjoy your blog. I appreciate learning about religion (specifically Christianity in this case) through the lens of high level metaphysical discussion.

This specific post is especially interesting as I have always thought that the "block universe" or the B theory of time conflicts with free-will, at least the libertarian kind. I apologize if I am not well versed or intelligent enough on this topic, but could you please give me your thoughts on how the B theory allows for free-will and a universe that does not have a timeline that is set in stone?

If the future is as real as the present and the past, does that mean it cannot be changed by choices "now"?

Perhaps I am missing some vital information that is not allowing me to make certain connections.

Thank you for taking the time, and again, your blog is a wonderful resource for someone like me who is trying to find God with a rational scientific approach.

68. JamesH says:

Hirad, I am sure that Aron will address this more fully, but I would just point out that prior *knowability* is not the same as prior *determination*. In other words, that something will be the case does not imply that it is the cause that something will be the case; it may be just the observation that something will be the case.

69. Aron Wall says:

In my view, all of time is as real as the present, as definite as the past, and as free as the future. The distinction between the three is only a matter of our own perspective, speaking of where events happen to fall relative to our current set of experiences.

I think talking about a "block universe" or time being "set in stone" risks confusing a particular visualization technique (which is really just a metaphor), with reality itself. In particular, when somebody complains that such a universe would be fixed, I think they are imagining spacetime as a 4d block which is static, or just "sitting there unmoving", with respect to some implicit 5th dimension of meta-time, i.e. the time of an observer sitting outside the universe saying "nothing is changing!". But this is a wrong way of looking at things. Such a "meta-time" dimension does not really exist.

Even God, who sees all time at once, does not see the universe as "unchanging", since God does not organize his experiences on a timeline the way we do. This would be incompatible with the doctrine of simplicity, i.e. that God has no parts (including temporal parts).

Just because there is only one specific future that will in fact occur, does not imply that it "could not have been otherwise". The modal distinctions between possible vs. actual vs. necessary outcomes can, in my opinion, be understood in a timeless way. There are a bunch of different spacetime histories that could have occured, one of which actually does occur (here I am thinking classically---quantum physics throws up some additional complications by allowing for quantum interference between different possible histories which end up the same way).

To talk about the future being "changed" by a present decision is also the wrong way to talk about free choice. This is using the framework of a time-travel story, where first there is some definite future X, then some meddler decides they don't like X, so they go back to the present moment to destroy the future X and replace it with a different future Y. But this is not how causality works in the real world. It would be better to say that there is only ever a single real future, but which future it is depends partly on your choices today.

70. Mr. C says:

Dear Aron,

I guess that a good addition to your very good answer one might find here: https://iep.utm.edu/foreknow/#SH6b. It's a very nice resolution of basically the same issue, just in terms of modal logic.