A Cosmological Argument for God’s Existence

This is a response to a guest-post at my friend Dan’s blog by Eric Steinhart.

Here’s a two-part argument for the existence of God meant to defuse some of my colleagues’s concerns.  For the purpose of this argument, let’s mean by “God” a necessary being (not necessarily unique) who is not part of the world but who is the sufficient explanation for its existence. The first part tries to establish that the world must have a sufficient cause G that is not the world itself or any part of the world. The second part tries to establish that that G exists necessarily. It isn’t the most elegant argument (in fact, the infinite regress argument in part II might be sufficient to prove the conclusion by itself), but I think it fits the dialectical situation.

  1. Principle of Sufficient Reason: Every contingent fact has a sufficient explanation.
  2. It is a contingent fact that the world exists.
  3. Therefore there must be a sufficient reason why the world exists. (1 and 2)
  4. No contingent thing can be a sufficient explanation of its own existence.
  5. Therefore, the world itself cannot be a sufficient explanation of its own existence. (2, 3, 4)
  6. If the world itself cannot be a sufficient explanation of it’s own existence, then there must be some G, which provides a sufficient explanation of the world’s existence, but which is not itself a part of the world.
  7. G either exists necessarily or exists contingently.
  8. Suppose G exists merely contingently.
  9. Then there must be a sufficient explanation of the existence of G. (1, 8 )
  10. G’ exists either necessarily or contingently, in which case we would need a G” which would have exist either necessarily or contingently, in which case . . .  and so on.
  11. In order to avoid an infinite regress, there must be some being who exists necessarily.
  12. Therefore, if G exists contingently, there is some being who exists necessarily. (8-11)
  13. If G exists necessarily, then there is some being who exists necessarily and is not a part of the world but provides a sufficient explanation of its existence, etc.
  14. Therefore there is some being who exists necessarily who is not a part of the world, but who provides a sufficient explanation for the existence of the world; i.e. God exists.  (7, 12, 13)

In defense of premise 1, I’ll just say (only half-facetiously) that it’s true because Alexander Pruss says so (click through for a link to his 2006 book on the PSR). Earlier, Dan made the psychologistic objection that it is just an accidental feature of the human brain that we are forced to think as if the PSR is true. So, he acknowledges that the PSR is a part of our commonsense reasoning, but wants to say that scientists have uncovered good reasons (quantum mechanical weirdness and the Penrose-Hawking singularity theorems) for doubting the PSR.  I don’t think this can be right, so here’s a little subargument (I’m not sure if this is how Pruss does it, b/c I haven’t seen his book).

  • 1.a Science can give us good reason for doubting the PSR only if there are some scientific observations that either demonstrate or imply PSR doesn’t hold.
  • 1.b If the PSR didn’t hold, we would never be able to trust our scientific observations.
  • 1.c Therefore, if the PSR didn’t hold, we wouldn’t be able to trust the observations that purport to show that the PSR doesn’t hold.

1.a is obvious. The PSR isn’t false just because Hawking says so. Science could only provide reasons to think it were false if it were observably false or if it was directly implied by something that was observable.

However, as 1.b, says, the PSR itself is presupposed by the practice of observation.  Scientific observation works by observing an event and inferring a cause that explains it. I see a streak of light in a bubble cloud chamber being deflected by a magnetic field and infer that the particle that causes the streak has a magnetic charge. But suppose the PSR is not true. Then my inference could be flat wrong for all I know, because it could be the case that the event of seeing a streak of light in a bubble cloud being deflected by a magnet isn’t caused by anything. So, if the PSR is false, we simply wouldn’t be able to trust any of the inferences we make from observing events. (Note that I’ve chosen this particular example because it involves a quantum event, not just a macroscopic one.)

The conclusion 1.c follows that putative scientific objections to the PSR are self-defeating. So, despite Dan’s psychologistic objections, I think there’s still good reason to hold the PSR.

In premise 2, by “the world” I intend all of the physical stuff in the universe. This would be the premise that Eric (following Bertrand Russell, I suppose) wants to reject. He says:

“As is well-known, you can interpret all the cosmological arguments as just being arguments for the existence of the physical world, rather than for God. Why is there something rather than nothing? Because the totality of physical things necessarily exists.”

I don’t find Eric’s response here terribly persuasive. So here are two subarguments in favor of (2).

First, to say that the physical world is necessary is to say that it is not possible for it not to be. Although controversial, the standard test for possibility is conceivability. If the existence of the world were necessary, then I could no more conceive of the world failing to exist than I could conceive a circle failing to be round. But I can conceive of the world not existing; therefore the world doesn’t not exist necessarily; therefore the world exists contingently.

Second, you can run an argument from the contingency of all of the part of the universe to the contingency of the whole without committing the fallacy of composition just by noting that composition is a fallacy only when the specific structure of the parts contribute to the whole’s having a property P which each individual parts lack. So, it would be committing the fallacy of composition to move from “Neurons are unconscious” and “brains are composed of neurons” to “brains are unconscious” just because it’s precisely the combination or structure of the unconscious parts that make the brain conscious.  Individual molecules of water don’t freeze, but collections of molecules of water do freeze because the chemical properties of the individual molecules allow crystalization at temperatures below 0 C.

However, necessity and contingency don’t seem to be that way. How would a combination or structure of non-necessary parts combine to give the totality the property of necessity? It’s utterly unclear. This seems to be a case of validly inferring a property of the whole from the property of the parts. There are other clear cases of when composition isn’t a fallacy. For instance, if every piece of a gold bar is gold, then the whole bar is gold too.

Premise (3) follows from (1) and (2).

Premise (4) says that no contingent thing can be a sufficient explanation of its own existence. This is because one thing that we want in a sufficient explanation is an efficient causal relationship, and it is trivially obvious that things can’t cause themselves. If x is the efficient cause of the existence of y then x must already exist (to do the causing) when y doesn’t (otherwise y wouldn’t already exist and wouldn’t be coming into being at all). Hence, x != y, and so nothing can be both the cause and the effect.

But if the world exists contingently, every contingent fact has a sufficient explanation (that must be something different than itself), then whatever provides a sufficient explanation of the world’s existence must be something different than the world, just as premise 5 says. Let’s call that thing G for the moment.

Now, we get to the second part of the argument, which will try to prove that G is a necessary being (or maybe is caused by a necessary being, if G is Plato’s demiurge, for instance).

(7) is an axiom of modal logic. G exists either necessary or contingent.

(8) is an assumption that G exists contingently to begin a reductio. The strategy here is to show that assuming either conjunct in premise (7) leads to the same conclusion, namely that there must be a necessary being.

(9) Follows from (8) and (1) by modus ponens. If G exists contingently there must be a sufficient explanation for it’s existence (per the PSR) and hence there would have to be some other being G’.

Premises (10) and (11) points out that the explanation of G cannot be an infinite series of contingent beings. This is because infinite regresses cannot provide sufficient explanations. If you say p is true because of r and r is true because of q and q is true because of . . .  ad infinitum you would never really have provided me an explanation of why p is true.

In the same vein, G cannot be caused explained by popping for an infinite series of other contingent beings, there has to be some necessary being at the head of the explanatory chain. So, just as (12) says, if G exists merely contingently there still has to be some necessary being. (NB. This necessary being has to be outside the world, and still gets to count as it’s sufficient explanation because causation/explanation is transitive: G is the cause of the world ex hypothesi, so if G’ is the cause of G and G is the cause of W, then G’ is also the cause of W, so G’ != W.)

So, if G exists contingently, there is a necessary being who is outside the world, etc. On the other hand, (13) if G exists necessarily, then there is still a necessary being outside the world, etc., namely G itself. Since those are the only two alternatives and the same conclusion follows either way, it must be true that there is a necessary being which isn’t a part of the world but which provides a sufficient explanation of the existence of the world, which is to say that God exists.

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About shanewilkins

I'm a philosophy grad student at Fordham University. I like medieval philosophy.
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15 Responses to A Cosmological Argument for God’s Existence

  1. Pingback: The Cosmological Argument, The Composition Fallacy, And More Reasons Not To Believe In God – Camels With Hammers

  2. Greg says:

    The argument about the contingency of the world’s existence is extremely problematic. I certainly don’t think you prove this for a number of reasons.

    First, we find things in science all the time that do not follow from our basic logical presumptions about the world. Just because we can conceive of something in the universe does not mean that the universes functions that way. I don’t see why the brain must function in such a way that the universe must be sensible to it. If you can imagine something, there is no reason why it has to have a connection to the universe. This is the problem with your first argument, if you can conceive of the world not existing it may have nothing to do with whether the world is logically necessary or not. It may just mean you don’t understand the basic physical premises that force the world/universe to be logically necessary (for that matter, no one understands them). If you cannot claim to have ultimate knowledge about the nature of the universe a priori, then this argument is nonsensical.

    Your second argument merely extends the first argument to the whole of the universe. However, this is also extremely contingent on a few things. First, you would have to prove that the laws of the universe function the same way in every part of the universe. I don’t think you can do that, as there is no observable or experimental way to prove it (and, as we know from physics, logic does not always suffice to tell us how the universe functions without experimentation to back it up). Secondly, though, you assume that that universe cannot be necessary without a specific world within the universe being necessary. Why does this property not fall victim to the fallacy of composition? You don’t actually prove that it doesn’t, you just give examples where it doesn’t without addressing the fundamental question: can the universe exist without this world existing? I don’t think you have, nor can you prove that without knowing the nature of reality from which the universe sprung. But, again, that’s what you are trying to prove. You are begging the argument here, sir, and you should avoid it.

    God cannot be proven to exist from your arguments. We find things in science every day that we don’t expect. How do you know that our universe and the entirety of creation is not just one great fluke of the probabilistic nature of entropy? I think that’s equally likely to god in your argumentation. It could be a quantum fluctuation as well. All of creation, all universes and N-Branes may have just always been, constantly in flux and forever creating new universes, new life and new possibilities. I don’t see your argument disproving these possibilities. At best, you just say there is a possibility of god’s existence that is not unprovable, but I don’t even think you get there as you can’t rule out experimental evidence against his existence.

  3. Pingback: No, I’m Not An Atheist By Faith, Here Are My Arguments. – Camels With Hammers

  4. Gary says:

    Hi Shane – like your argument, very sympathetic, and found your account of composition in this context very clear and helpful. I have just one question and worry:

    You say that you can conceive of the world not existing. I’m a bit unclear about this move though. Specifically, I’m not quite so sure about what it is that you take yourself to be conceiving.

    I imagine you might be thinking something along the lines of, “Just that, the universe not existing”. Or, perhaps, “Nothing, just – Nothing. Nothing now, nothing in the past, nothing ever coming about in the future.”

    I won’t deny that it’s possible to say such things. I’m a bit confused as to what the associated concept would be though.

    One could imagine making a Berkeley-style point here. One can try to conceive of nothing, of the universe not existing, etc. But, as one attempts to fix one’s gaze on this idea, it seems that sooner or later, some, previously unnoticed observer (i.e. – You!) starts to rear his ugly head, observing the nothing. This though, of course, is not the idea of nothing, nor is it the idea of the universe, were it not to exist.

    Call this Anselm’s reverse-revenge (or Gaunilo’s glory, or Plato’s problem, or whatever you will).

    The question then is, what is it you mean, when you say that it is conceivable that the universe not exist?

    (This, of course, plays no small part in assessing the plausibility of the claim that the universe is a metaphysically possible entity.)

  5. James Gray says:

    Principle of Sufficient Reason: Every contingent fact has a sufficient explanation.
    “It is a contingent fact that the world exists.”

    If the world has always existed, then we might not have anything to explain.
    If the world can pop into existence, then we might not have anything to explain.

    To know for sure what to think about the existence of the universe, we need to better understand what a “contingent fact” is and why they must have explanations.

    Explanations might end somewhere. We might not need to explain things forever. We need to understand why. I am not convinced that it’s only when we find a “necessary fact.” Is it a necessary fact that only necessary facts don’t need an explanation? If so, how do we know that?

  6. shanewilkins says:

    Thanks for the comment Greg, here’s a couple short responses to try to help.

    “If you can imagine something, there is no reason why it has to have a connection to the universe.”

    The issue is whether conceivability entails possibility, not actuality. The idea is supposed to be that that the only real test we have to determine what’s possible (as opposed to what is actual) is by trying to conceive of something. Conceiving isn’t quite the same thing as imagining a mental picture. It’s something like being able to form a clear conceptual understanding of something. So I can conceive exactly what a thousand sided regular polygon would be, even though I can’t really find anything in my imagination that distinguishes my mental image of a 1000-gon from a 999-gon, say.

    But I cannot conceive of impossible things like round squares or colorless green leaves. You can’t “conceive” of those things because there’s just nothing there to be understood about a round square. So conceivability is basically our only real source of evidence for knowledge of metaphysical possibility.

    Further, there is a very difficult question about why it should be the case that the world is capable of being understood by human beings. This is just a new variation on an old argument about psychologism, which, originally, was the view that the truths of logic (and mathematics) are just facts about human psychology. You and Dan both seem to want to take some kind of psychologistic line about the PSR–”Hey look, modern physics tells us crazy counter-intuitive stuff that is hard to believe; but it’s only hard to believe because our primate brains didn’t develop to observe the subatomic world.” This doesn’t cut ice though because–as I argued above–the very observational practices that are supposed to verify these wacky modern physical claims presuppose the truth of the principle of sufficient reason.

    “Why does this property not fall victim to the fallacy of composition?”

    I answered this in the body of the post and don’t know how to put the point any more clearly.

    “All of creation, all universes and N-Branes may have just always been, constantly in flux and forever creating new universes, new life and new possibilities.”

    The thing that is interesting about cosmological arguments like the one I gave above is that they are compatible with the world having existed eternally. I don’t think it did, of course. But the point about the impossibility of an infinite regress still holds even on the assumption that the universal has always existed, because what is held to be impossible in this argument is an infinite regress of explanations, not a temporal regress. So, even if the universe has just inflating and collapsing eternally, it would still be a contingent thing and hence ultimately in need of explanation by a non-contingent thing. To see why, recall that something is contingent if it is possible for it not to be. Nothing about that definition entails that there actually must be some specific moment at which the contingent thing fails to exist. So a thing can be eternal and nevertheless contingent.

  7. shanewilkins says:

    Hi Gary,

    Thanks for chiming in. I don’t mean to be saying anything mysterious, but it’s possible that I’ve been a bit sloppy and therefore misleading. Perhaps I should have said it like this:

    1. I can conceive of a possible world in which no concrete objects exist.
    2. Anything conceivable is metaphysically possible.
    3. Therefore it is metaphysically possible that no concrete objects exist.

    Actually I think I may have stumbled my way into another problem for Dan and Eric. So suppose “the universe” is just the set of all the concrete objects in the world. In the case where there are no concrete objects, the universe still exists, it’s just the null set. Superficially, it looks like that gives Dan just what he wants: a definition of “the universe” under which it exists necessarily. The problem is that Dan and Eric seemed to want “the universe” to stand in for “God” as the conclusion of the cosmological argument.* But if the universe is a set, that clearly isn’t going to do. “God” provides a sufficient explanation for the existence of contingent things. “The universe” can’t do that, because “the universe” is a set and sets don’t have causal or explanatory powers because they are abstracta. Sets of guns don’t kill people; guns do. Set of concreta don’t explain the existence of objects; a concretum does.

    What do you guys think about that?

    * Quote from Eric: “As is well-known, you can interpret all the Cosmological Arguments just as being arguments for the existence of the physical world, rather than for God.”

  8. shanewilkins says:

    Hi James, thanks for your very interesting questions. I don’t quite know what to say in defense of the PSR though. My argument above just takes it as a first principle. I guess I should really get into Pruss’s book and see what he has to say about it. What are your thoughts on the question?

    Also, I would like to say this: Assuming you don’t take a statistical interpretation of modality, I think you still need a sufficient explanation to account for the existence of an infinite temporal sequence of causes, as I said to Greg above.

    Brian Davies has a really lucid explanation of why this is supposed to be in his book, “The Thought of Thomas Aquinas.” The issue there is that Thomas thinks it isn’t provable that the world is not eternal, but he still gives these infinite regress style arguments for God’s existence. Davies has something very clear to explain why Thomas didn’t think these two views conflicted.

  9. James Gray says:

    shanewilkins,

    Thank you for taking the time to respond.

    Hi James, thanks for your very interesting questions. I don’t quite know what to say in defense of the PSR though. My argument above just takes it as a first principle. I guess I should really get into Pruss’s book and see what he has to say about it. What are your thoughts on the question?

    I don’t really understand how it works. I don’t fully know what “necessary” means, but I know even less how to identify “contingent facts” or “sufficient explanations.” Some examples might help. Take induction. We think induction works and the future will be like the past, but is that a necessary or contingent fact? Either way, many people want such ideas to be “justified.”

    I see epistemology in a few ways. One, the coherence theory. Two, self-evidence, which I’m not sure sure about. (Does metaphysical conceivability or intuition require that? My graduate metaphysics class actually favored intuition over conceivability, but I can’t remember all the details.) Three, there are various theoretical virtues and the theory with the most wins.

    Also, I would like to say this: Assuming you don’t take a statistical interpretation of modality, I think you still need a sufficient explanation to account for the existence of an infinite temporal sequence of causes, as I said to Greg above.

    I don’t quite understand your response to that issue. Do you think it’s inconceivable? If so, why?

    Also, I mainly concerned myself with the idea of the universe popping into existence. Sure, we can’t imagine an explanation for that, but maybe there isn’t one. My main problem with this possibility is that it’s against a supposed scientific fact.

  10. shanewilkins says:

    Please, call me Shane.

    You write,

    “I don’t fully know what ‘necessary’ means, but I know even less how to identify ‘contingent facts’ or ‘sufficient explanations.’”

    I don’t see the source of your perplexity here. You can offer the familiar possible-worlds semantics definitions of all of these claims. A being is “necessary” in the broad, metaphysical sense my argument relies upon iff it exists in all possible worlds. A fact is contingent if it is true in some worlds but not in others. It is a necessary fact that the whole is greater than one of its parts because it is true in all possible worlds. However, the fact that Obama won the presidency is a fact because it’s true in the actual world, but it is contingent in that it was metaphysically possible that it not obtain: there are possible worlds in which McCain won.

    I’m not sure what to say to your query about induction. I can conceive a possible world W* just like our own up until 2012, when the values of the constants in the laws of nature begin to slowly shift . . . So, if it’s a fact that the future will be like the past, it’s a contingent fact.

    You’re right that I need to say something about what “sufficient explanation” is meant to be. It seems hard to characterize precisely, but here are some examples. Take a contingent event such a window shattering. A “sufficient explanation” of the event of the window shattering is going to involve a set of sufficient conditions for the occurrence of the event, such as mass and velocity of the brick, the shear strength of the windowpane and so on.

    I’m not sure if this really works though because it looks to me like there are some kinds of explanations that don’t provide sufficient conditions. I’m hungry and believe there is cake in the fridge, so I get up and get a piece. I’m tempted to call that a “sufficient explanation” because the presence of my hunger and my beliefs and the presence of the cake somehow explain why I did what I did. However, being hungry and believing there is cake in the fridge surely aren’t jointly sufficient at least not in general because I’ve been hungry in the presence of cake before without eating it. Nevertheless, this time the cake and my hunger do explain my eating, even though they aren’t sufficient conditions in general, so either they must be sufficient conditions, just in this specific case or “sufficient explanation” must involve something other than just identifying sufficient conditions. I’m not sure quite what to say next about this though.

    Here are some clarifications on my remarks from the end. By a statistical interpretation of modality I mean just defining whatever exists eternally to be necessary. But in response to your prodding, I guess I would say that I think it is inconceivable that something contingent exist without there being some explanation why it exists. As you say, this is against a supposed scientific fact, which is a valid concern to have. I don’t have the technical apparatus to be a competent judge whether these scientific facts are veridical or merely specious appearances.

  11. shanewilkins says:

    *sorry, hit return too early*

    I don’t have the technical skill to judge whether Hawking is right about the interpretation of the math. But I have some good a priori reasons to think things just can’t be the way he says they are. Still, I can understand one not being convinced of this in the absence of a competent appraise of this purported scientific evidence to the contrary. Maybe one day I’ll have time to bone up on this stuff, but I don’t right now, unfortunately.

  12. James Gray says:

    Shane, you said the following:

    I don’t see the source of your perplexity here. You can offer the familiar possible-worlds semantics definitions of all of these claims. A being is “necessary” in the broad, metaphysical sense my argument relies upon iff it exists in all possible worlds.

    Defining necessary in terms of possibility is notoriously circular. I would then have to know what a possible world is. For example, some argue that water is H2O by metaphysical necessity, but I just think that we have identified that the stuff we called water was H2O all along. It would be strange to suggest it might have been something else all along without merely saying we misidentified it’s chemical composition in the first place.

    A fact is contingent if it is true in some worlds but not in others. It is a necessary fact that the whole is greater than one of its parts because it is true in all possible worlds. However, the fact that Obama won the presidency is a fact because it’s true in the actual world, but it is contingent in that it was metaphysically possible that it not obtain: there are possible worlds in which McCain won.

    The first example sounds true by geomentrical standards and might therefore be true by logical necessity. I tend to agree that logic restricts metaphysical possibilities or entails metaphysical impossibilities, but I don’t know that it can be proven with absolute certainty. The second example is one I can agree with.

    I’m not sure what to say to your query about induction. I can conceive a possible world W* just like our own up until 2012, when the values of the constants in the laws of nature begin to slowly shift . . . So, if it’s a fact that the future will be like the past, it’s a contingent fact.

    So, you are saying that conceiving of something is enough to prove something is contingent. I’m not sure that is correct.

    You’re right that I need to say something about what “sufficient explanation” is meant to be. It seems hard to characterize precisely, but here are some examples. Take a contingent event such a window shattering. A “sufficient explanation” of the event of the window shattering is going to involve a set of sufficient conditions for the occurrence of the event, such as mass and velocity of the brick, the shear strength of the windowpane and so on.

    It sounds like sufficient explanation can just be a description of what happens, perhaps with the addition of laws of physics. The laws of physics can also just be considered to be descriptions that involve predictability. If the universe always existed, then we would say that X was caused by Y, Y was caused by Z, ad infinitum. Every single event could be easily given sufficient conditions, but we couldn’t say that the universe ever had a beginning state.

    If matter can pop into existence, and I can conceive of such a thing, then we might have to admit that it’s simply false that contingent facts have to have causally sufficient conditions (what you call sufficient explanation) because such a law of physics is contingent just like all other laws of physics.

    We can formulate the following argument:

    1. All contingent facts require a sufficient explanation.
    2. All contingent facts are facts that exist in less than 100% of possible words.
    3. We know that a fact is contingent if we can conceive of it not applying to one possible world.
    4. The laws of physics are contingent because we can conceive of them being different or non-existent in a possible world.
    5. One law of physics is that matter can’t pop into existence. (Matter can’t be created or destroyed, which is based in part on the first law of thermodynamics.)
    6. Therefore, matter can pop into existence in at least some possible worlds.

    It could even be possible for a law of physics (the first law of thermodynamics) to not exist for a period of time then start existing at some point.

    I’m not sure if this really works though because it looks to me like there are some kinds of explanations that don’t provide sufficient conditions. I’m hungry and believe there is cake in the fridge, so I get up and get a piece. I’m tempted to call that a “sufficient explanation” because the presence of my hunger and my beliefs and the presence of the cake somehow explain why I did what I did. However, being hungry and believing there is cake in the fridge surely aren’t jointly sufficient at least not in general because I’ve been hungry in the presence of cake before without eating it. Nevertheless, this time the cake and my hunger do explain my eating, even though they aren’t sufficient conditions in general, so either they must be sufficient conditions, just in this specific case or “sufficient explanation” must involve something other than just identifying sufficient conditions. I’m not sure quite what to say next about this though.

    This seems like evidence that sufficient conditions might not always exist. Free will might be an example of an everyday occurrence of causally sufficient conditions to be lacking. Free will, if it exists, would be a case of an “unmoved mover” similar to God, which seems to require that sometimes causally sufficient conditions are lacking. We could give “first causes” using our free will.

    I guess you might say that God and perhaps human minds or souls don’t have to follow the laws of physics, but that (a) leads to problems dualistic interaction and (b) requires us to admit that God, minds, and/or souls are necessary rather than contingent. You said that all contingent facts require sufficient explanations, but such explanations would be impossible to give for God and the freedom of the will. But I can conceive of a person making two different decisions using the freedom of the will within two different possible words, so the freedom of the will combined with your conceivability epistemology leads us to accept that free will is contingent.

    We could then formulate the following argument:

    1. Assume that all contingent facts require a sufficient explanation.
    2. All contingent facts are facts that exist in less than 100% of possible words.
    3. We know that a fact is contingent if we can conceive of it not applying to one possible world.
    4. We know that free will leads to contingent facts because we can conceive of it applying differently in two possible worlds.
    5. Therefore, free will leads to facts with causally sufficient conditions.
    6. But free will can’t offer us a sufficient causal conditions for events.
    7. Therefore, not all facts require causally sufficient conditions after all.

  13. shanewilkins says:

    James,

    Very interesting stuff here. I’ll give you the last word if you care to take it, because I don’t think I’ve got much new to add to the conversation.

    One quick thing though. Your argument moves from:

    4. The laws of physics are contingent because we can conceive of them being different or non-existent in a possible world.
    5. One law of physics is that matter can’t pop into existence. (Matter can’t be created or destroyed, which is based in part on the first law of thermodynamics.)
    6. Therefore, matter can pop into existence in at least some possible worlds.

    I think (5) is the wrong premise. Suppose the principle of sufficient reason were a necessary metaphysical truth like “the whole is greater than one of its parts”. Then it would be the case in all possible worlds that things couldn’t just pop into existence without causes. Therefore, surprisingly, the first law of thermodynamics would hold in all possible worlds because it would be a consequence of a necessary truth.

    What do you think about that?

  14. James Gray says:

    Shane,

    It is possible that “matter can’t be created” is a metaphysical rather than physical law, but such a position could be taken to be less parsimonious. That which is metaphysically necessary is also physically necessary, so metaphysical necessity is more ambitious. I do think I can “conceive” of matter popping into existence, as I already said.

    Let’s assume that this law is metaphysical. How would we know that? Conceivability seems to fail us in this regard, and therefore conceivability could be inadequate to deal with metaphysical necessity. Ordinary evidence (induction) seems to confirm the law, but that would be true even if the law was physical. Additionally, you argued that induction itself is plausibly contingent insofar as the future will resemble the past only in certain possible worlds.

  15. Gary says:

    Hi Shane,

    I hate to be a nit-picker, this is a blog after all, but I’m going to do it twice anyways, once more on this post, and once on the next. Here, my nitpick is with:

    “1. I can conceive of a possible world in which no concrete objects exist.”

    This seems just as fundamentally mysterious of a conception as before. Perhaps, however, I am interpreting conceivability to much in line with imaginability, with the latter understood in a pictorial sense. Still, I still have a hard time ‘conceiving’ what would be involved in [1] above.

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