Showing posts with label necessity. Show all posts
Showing posts with label necessity. Show all posts

Friday, February 24, 2023

Christophe de Ray's Conceptual Cosmological Argument

Introduction

This argument is due entirely to Christophe de Ray, and is presented in his excellent paper "Existence exists, and it is God" (2022). This post is effectively a summary of the argument as I understand it, and is written largely as a way to help me organize my own thoughts on the matter. I highly encourage all who read this to check out de Ray's original paper.

Summary of the Argument

The argument may be summarized as follows:
  1. All particular things exist in virtue of their having or sharing in something, which we call Existence.
  2. Existence could not enable particular things to exist unless it itself exists.
  3. Therefore, Existence exists.
  4. If Existence exists, then it is a supremely excellent being.
  5. Therefore, Existence is a supremely excellent being.
(1) is motivated by the typical arguments for existence as a first-order property (e.g. the inability of the Frege-Russell view to properly analyze singular existence statements). (2) seems self-evident, while (3) follows logically.

Motivating (4): "If Existence exists, then it is a supremely excellent being"

(4) is the most substantive premise, and obviously stands most in need of defense. The idea here is that we need to give some account of how Existence itself is able to exist. After all, if all particular things receive their being from Existence, then how can Existence itself exist? Surely it cannot bestow being on itself, for this would require that Existence be ontologically prior to itself (which is surely incoherent). Hence, it seems that we must say that Existence itself exists in a different way from how other things exist: while all other things exist in virtue of their standing in a certain "sharing" relation to Existence, Existence itself is a paradigm existent, the existence of which consists in its self-identity. De Ray proposes the following account of existence:
Paradigm Theory (PT): x exists if and only if either x is identical to the paradigm existent, namely Existence, or x bears the ‘sharing’ relation to Existence.

In order to make sense of this account, de Ray proposes an analogy. There are two ways in which something might satisfy the predicate "is a The Starry Night painting": one way is to be a copy or imitation of the original van Gogh painting, while another way is simply to be the original van Gogh painting. The copies satisfy the predicate in virtue of their standing in the "being a copy" relation to the original painting; however, the original van Gogh satisfies the predicate simply of virtue of its self-identity. Similarly, while all other things exist in virtue of their standing in the "sharing" relation to Existence, Existence itself exists in virtue of its self-identity.

So, Existence is a paradigm existent. But what kind of thing would a paradigm existent be? Plausibly, to be a paradigm F is to be a "perfectly good or true instance of F. [...] Obviously, no particular F could be better or more truly than the paradigm F, since if it [was], then it would be the paradigm. For example, it is impossible for any painting to be a better or truer The Starry Night painting than van Gogh’s original" (de Ray 2022, 6). "

This analysis implies that there can be better or worse ways of existing, with the paradigm existent being a perfect instance of existence. "This accords with our intuition that while both humans and oysters are real, the existence of the former is superior to that of the latter, in virtue of some of the attributes that humans have and that oysters lack, such as self-awareness, creativity, the ability to form relationships, etc. [...] But if the paradigm existent is a perfect instance of existence, and thus exists in a perfect way, then it follows that Existence must possess all the excellence that it is possible for a being to possess. This must surely include consciousness, intelligence, rationality, and indeed maximal power, knowledge and moral goodness, to name only some. Whatever the exact nature of such a being, it is surely appropriate to call it a supremely excellent being" (ibid., 6-7). Hence, (4) is true, while (5) follows logically from (1)-(4).

A Potential Objection (and its Resolution)

Are there any objections to all of this? Here is one: before an object can instantiate a property, it must first exist. But on this account, objects exist in virtue of their standing in a certain relation, i.e. that of imitating the paradigm existent. "It could therefore be objected that our account is incoherent, because imitation can never be prior to the existence of the imitator" (ibid., 12).

De Ray argues that this difficulty is best resolved by considering more carefully what it means for a particular thing to imitate the paradigm existent. Consider again the van Gogh case: what it is for a copy of The Starry Night to stand in the imitation relation to the original painting is simply for it to be modelled on the original, i.e. for it to be created in a certain way by a creative agent. It does not have to exist before it can be a copy of the The Starry Night; rather, it just is a copy of The Starry Night for as long as it exists, in virtue of its having been made in a certain way.

Returning to the case of existence, if we think of the imitation relation as a kind of creation, "the objection at hand vanishes, because it is clear that the existence of a created thing is not ontologically prior to its being created. It would be strange indeed to argue that ordinary existents are created by the paradigm because they exist, and far more plausible to say that they exist in virtue of being created" (ibid., 12).

It is also useful to note that while in the van Gogh case the creation is done by a "third party" (i.e. the painter), who is distinct from the paradigm case (i.e. van Gogh's painting) and the created imitations, in the case of existence there can be no third-party, since everything other than the paradigm existent is an ordinary existent. Any creative agent other than the paradigm existent itself "would thus need to create [itself] to resemble the paradigm existent, which is absurd. Thus, it is the paradigm itself that would need to do the creating, modelling ordinary existents after itself" (ibid., 12). We thus have the result that Existence is a supremely perfect being, which is responsible for creating all other things. "And this," as Aquinas put it, "everyone understands to be God."

Monday, April 11, 2022

A Convenient Way to Explain Metaphysical Modality

Consider the following question: could the laws of nature have been different?

According to physical modality, the answer is trivial: no, of course the laws of nature could not have been different. After all, physical modality just is the range of what is the modal space governed by the laws of nature.

According to logical modality, the answer is similarly trivial: yes, of course the laws of nature could have been different. After all, there is nothing logically incoherent about the idea that, say, the speed of light could have been slightly faster or slower than it in-fact is. 

Metaphysical modality, then, is that form of modality which renders non-trivial the question "could the laws of nature have been different?"

Tuesday, March 22, 2022

Dore on Rowe on the Cosmological Argument

I recently came across an old paper by Clement Dore, entitled "Rowe on the Cosmological Argument" (1983). In it, Dore objects attempts to uphold Hume's objection to the PSR, by critiquing Rowe's defense of the principle. He writes:

[In] order to support the cosmological argument, PSR must be interpreted this way: "For any infinite set, S, each of whose members can be explained by another member, the question 'Why are there any members of S?.' can (only) be truly answered by referring to a cause which is not itself a member of S." But how much credibility has PSR, thus interpreted? Consider the question, "Why are there any things which are at least as large as a quark?" Rowe's claim that PSR (as presently interpreted) may be plausible appears to commit him to the thesis that the following may be plausible: "If there is a finite number of members of the set of things which are at least as large as a quark (call it S'), then S' is like my philosophy of religion class, in that we do not need to infer an irreducibly distinct cause of its having members. However, if S' has an infinite number of members, then it is subject to a causal explanation which does not reduce to the individual explanations of the individual members, namely, the following one: The individual members of S' exist because there is something smaller than a quark which is their ultimate cause." 

But of course, Dore argues, it is absurd to suppose that there must be something smaller than a quark which is the ultimate cause of the set S'. And since PSR (allegedly) commits one to such a claim, it seems that PSR must be rejected.

I found this line of argument noteworthy, if only because of how absurdly weak it seems. Firstly, because the cosmological argument doesn't require one to assume any infinite set of objects; the argument from contingency (for example) works identically well whether the totality of all contingent things is finite or infinite.

But there's another issue with Dore's line of reasoning. For assuming that S' has infinitely many members, it seems that we may still avoid his claim of absurdity with relative ease. Example: suppose that the universe had a beginning in time, with an initial state and physical laws that were/are metaphysically necessary (this is the view taken by, among others, Graham Oppy). In that case, S' would be explained by the initial state of the universe, in tandem with the laws of nature that necessarily follow from it. This claim hardly seems absurd, and it is hard to believe that it should lead one to abandon PSR.

Alternatively, suppose that the universe has existed for eternity, and that its existence is metaphysically necessary. In that case, we have a number of options. For instance, S' might be metaphysically necessary (e.g. if the universe is necessary and past eternal, and S' includes everything in the universe, it follows that S' is metaphysically necessary). Alternatively, S' might be explained by the laws of nature in tandem with the most fundamental physical entities, and these things might be metaphysically necessary. Or else, if nothing in the physical universe is necessary, then S' would need to be explained by something outside of the universe, in which case the cosmological argument is sound. None of these options seem so absurd as the merit the rejection of PSR.

[Note: Dore might consider the last result (i.e. the cosmological argument being sound) to be absurd; however, this would hardly constitute a genuine reply to that argument. For then Dore would be arguing as follows: "The PSR as required by the cosmological argument is absurd, because if it were true, it would entail the success of the cosmological argument." This might be sufficient grounds for rejecting PSR, but it will certainly not convince anyone who regards the cosmological argument as sound.]

Friday, January 14, 2022

Richard Carrier Doesn't Understand [Insert Concept Here]

Richard Carrier (an atheist blogger suffering from the world's most ironic god complex) thinks he has an argument to the effect that "[if] there was once absolutely nothing... it necessarily follows that there is an infinite multiverse." How does he get there, you might wonder? Well, like this:
[If] nothing exists, then by definition no rules exist limiting what will happen to it; if no rules exist limiting what it will happen to it, it is equally likely it will become one of infinitely many arrays of things (including remaining nothing, which is just one of infinitely many other things no rule exists to prevent happening); if we select at random from the infinitely many arrays of things it can become (including the array that is an empty set, i.e. continuing to be nothing), the probability is infinitesimally near 100% the array chosen at random will be a vast multiverse whose probability of including a universe like ours is infinitesimally near 100%. Because there are infinitely more ways to get one of those at random, than to get, for example, the one single outcome of remaining nothing. There is no way to avoid this. Unless you insert some law, power, rule, or force that would stop it, or change the outcome to something not decided at random. But once you do that, you are no longer talking about nothing. You have added something. Which you have no reason to add. Other than your human desire that it be there. Which is not a compelling argument for it being there.

Now, perhaps it's just me, but I must admit that this passage made me scratch my head. This is because Carrier consistently identifies himself as a "neo-Aristotelian." But as Robert Koons (UT Austin), William Simpson (Cambridge), and Nicholas Teh (Notre Dame) point out, it is a defining feature of neo-Aristotelian metaphysics that "[it] embraces what is commonly called a causal powers ontology, in which both active and passive powers are regarded as fundamental features of particular things in the world that bring about change by some kind of natural necessity" (Neo-Aristotelian Perspectives on Contemporary Science, Routledge, p. 1). But this idea wrecks havoc with Carrier's argument. Allow me to explain.

Metaphysicians agree that "powers and dispositions are properties of things" (The Atlas of Reality: A Comprehensive Guide to Metaphysics, Wiley-Blackwell, p. 106). Furthermore, Aristotelian accounts of modality hold that "a proposition is possible if there is some actually existing thing that has the power to bring about the truth of that proposition" (ibid, p. 348). In other words, a neo-Aristotelian metaphysic is one characterized (in part) by the claim that all possibilities and potentialities are grounded in the properties of actually existing things. More specifically, they are grounded in the powers of concrete objects, here defined as "objects [which] can change other concrete objects, and are able to undergo change themselves" (ibid, p. 321).

But here arises the difficulty. For Carrier wishes to claim that an infinite multiverse can emerge from a "nothing-state," defined as a state of affairs in which "nothing whatever exists except anything whose non-existence is logically impossible." But presumably, this means that the "nothing-state" includes no concrete objects (if it did, one would think it could not qualify as a "nothing-state"). So Carrier is forced into something of a dilemma, with only two possible outcomes:

  1. The "nothing-state" does possess causal powers, in which case it has properties, in which case it is not nothing, but rather a concrete object. A very vague and nebulously-defined concrete object, true, but a concrete object nonetheless.
  2. The "nothing-state" does not possess causal powers, in which case any self-respecting neo-Aristotelian will simply reject the claim that it could give rise to an infinite multiverse, on the grounds that such a thing is metaphysically impossible (i.e. no concrete objects = no causal powers = no potentialities = no infinite multiverse).
And of course, neither disjunct is favorable to Carrier's argument.

[Incidentally, lest Carrier (or his fans) should feel tempted to deploy his favorite strategy (i.e. accusing all who oppose him of "science illiteracy"), it should be noted that William Simpson "was formerly a researcher at the Weizmann Institute of Science, and holds a doctorate in physics from the University of St. Andrews," while Nicholas Teh "held postdoctoral research fellowships at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge and the Quantum Group at the Oxford University Comlab." Thus giving both of them infinitely more credibility on scientific matters than Richard Carrier, who has no formal training in physics (or any other scientific field), can rightfully dare to claim. And of course, many other eminent philosophers of science (such as Nancy Cartwright) take a similar neo-Aristotelian view.]

This leaves only one question: how in the hell did Carrier get this so badly wrong? Isn't he a neo-Aristotelian? In fact, upon closer inspection, it seems that Carrier rejects almost everything that characterizes neo-Aristotelian philosophy. For instance, in his "reply" to Edward Feser, he writes that "'essences' don’t exist. And we’ve long known they don’t exist." But this blatantly contradicts mainstream neo-Aristotelianism, which holds that "substances in nature belong to recurring natural kinds, each with its own intelligible nature or essence" (Neo-Aristotelian Perspectives on Contemporary ScienceRoutledge, p. 2).

So what exactly is going on here? Well, wouldn't you know it, it turns out that Richard Carrier has managed to convince himself that he (and basically only he) understands Aristotle better than the entire philosophical community put together! Case in point:
Most Neo-Aristotelianism today (like much of what Ross Inman is talking about) is crank theistic claptrap. Like Medieval Aristotelianism, it gets practically everything wrong about what Aristotle even thought or taught.

Oh, well that settles it then! Never mind the fact that Ross Inman has a PhD in philosophy from Trinity College Dublin, whereas Carrier has zero formal training in philosophy. Never mind the fact that Inman has published a book with Routledge, not to mention articles and book chapters in the American Philosophical Quarterly, Philosophical Studies, and Oxford Studies in Philosophy of Religion, whereas Carrier has no philosophical CV to speak of (and distorts his publishing credentials to boot). The great and powerful Richard Carrier has spoken, and really, what more proof do you need?

This is all rather silly, of course. Carrier has repeatedly shown himself to be incompetent, first in his own field of ancient history (exhibit A, exhibit B, exbibit C, etc.), then in the use of his favorite hobby-horse, Bayes' theorem (exhibit A, exhibit B, exhibit C, etc.); as such, it's worth asking why anyone would even begin to take him seriously on matters of philosophy, especially when there are so many respectable atheist philosophers of religion out there (such as Graham Oppy, J.L. Schellenberg, Paul Draper, and so on). But I'm afraid that mystery is rather above my paygrade.

Wednesday, December 29, 2021

Richard Carrier's Argument from Specified Complexity

Noted pseudo-philosopher Richard Carrier has an argument which, he thinks, demonstrates that "we should think the supernatural is impossible." Specifically, he wants to claim that "God's mind appears to be logically impossible." His line of reasoning goes (more-or-less) as follows:

  1. (Assume for contradiction) God's mind is simple and immaterial.
  2. God's mind must be able to store and process information.
  3. Information storage and processing require specified complexity.
  4. Such complexity requires some material on which information can be stored and circuitry stamped.
  5. God's mind is complex and material (from 2-4).
  6. Contradiction (from 1 and 5). 
Unfortunately, Carrier seems to have gotten himself tripped up on the nature of God's knowledge. For he writes:
A god has to know things (store information), and think things (process information). But there is a difference between correct and incorrect information, present and absent information; between conflation and distinction. A god has to be able to distinguish one person’s face, from another; and correctly connect each face, with other information about the corresponding person, like that Joe’s face goes with Joe’s job in sales and wife of eleven years, and Mark’s face goes with Mark’s service in the military and husband of eleven years. That information could be connected up differently—wires crossed, and Joe’s face gets incorrectly linked to Mark’s husband, producing the false information that Joe has a husband, and so on. And notice how many different ways connections can be crossed up: the more information, the more different connections are possible. And most of them (in fact, all but one of them; out of effectively infinitely many) will be false.

However, as the physicist Aron Wall pointed out in response to a near-identical objection (ironically put forward by a couple of conservative Mormons), "This is only an issue if you assume that God's knowledge is, like ours, representational, that is, that it proceeds by means of making something like an image or duplicate of the object known, in some other physical system (in our case, the brain)." But of course, classical theism does not make such an assumption; rather, it has always held that God knows all things via direct awareness, simply by knowing Himself as creator and sustainer of all things (hint: this is part of what CTs mean when we say that God's knowledge, creative act, etc. are really all one thing). Thomas Aquinas provides a useful summary of this concept, when he writes:

Now, it is not repugnant to the simplicity of the divine mind that it understand many things; though it would be repugnant to its simplicity were His understanding to be formed by a plurality of images. [...] Inasmuch as He knows His own essence perfectly, He knows it according to every mode in which it can be known. Now it can be known not only as it is in itself, but as it can be participated in by creatures according to some degree of likeness.  But every creature has its own proper species, according to which it participates in some degree in likeness to the divine essence. So far, therefore, as God knows His essence as capable of such imitation by any creature, He knows it as the particular type and idea of that creature; and in like manner as regards other creatures. So it is clear that God understands many particular types of things and these are many ideas. (ST I.15.2)

The idea that God's knowledge does not consist in stored-up beliefs or mental images may also be found outside of the Thomistic tradition. For example, William Alston (1986), a critic of divine simplicity, was nevertheless a major proponent of the idea that God has no beliefs whatsoever, but rather knows all things via direct awareness. To quote:

A creature in our condition needs inner representations in order to be able to think about absent states of affairs, since the facts are rarely if ever directly present to our consciousness. But since God enjoys the highest form of knowledge He is never in that position, and so He has no need for inner representations that He can ‘carry around with him’ for use when the facts are absent. The facts are never absent from His awareness; thus it would be fatuous to attribute to Him any such mental map. When we have arrived at our destination we can fold the map away.

In a recent paper defending Alston's view, Saeedimehr (2021) discusses two non-propositional accounts of God's knowledge, each of which would seemingly allow us to avoid Carrier's argument. To quote:

Since God is absolutely simple, He (His essence) is identical with his knowledge. Therefore, God’s knowledge is totally simple and hence it is beyond any kind of complexity, including the complexity due to having a propositional structure.

Since Alston finds the principle of Divine simplicity quite problematic, he seeks another basis for the non-propositional position. He argues that as human beings, our propositional knowledge stems from two of our limitations: first we ‘cannot grasp any concrete whole in its full concreteness’, and second ‘we need to isolate separate propositions in order to relate them logically’ and then ‘extend our knowledge inferentially’. But since God is obviously beyond these limitations, His knowledge is not required to be propositional.

It would seem, then, that a non-propositional account of God's knowledge allows us to reject premise (2) of Carrier's argument; namely, that God's mind stores and processes information. God does not store information at all (or to quote Alston, "carry [it] around with Him"); rather, at any one moment He has an infallible intuitive grasp of all facts. Similarly, God does not need to "process information" (or to quote Alston, "isolate separate propositions in order to relate them logically"). We need to do that, because our cognition is fallible and limited; God, on the other hand, is far beyond such things.

One hopes that Carrier himself never gets wind of this post, lest I be subjected to his, uh... scholarly rigor.

Sunday, December 19, 2021

Do Theistic Arguments Support the Simulation Hypothesis?

Richard Brown believes that "the traditional arguments for God’s existence provide better support for the simulation hypothesis than they do for the traditional God of Theism." He basis this view on the following argument:

  1. The traditional a posteriori arguments (cosmological, teleological, etc.) point, if one accepts their conclusions, to a creator, but not to what kind of creator.
  2. The traditional theistic God (all-powerful, all-knowing, and morally perfect) is one candidate for being the Creator.
  3. The Simulators are another candidate.
  4. The traditional arguments do not distinguish between (2) and (3).
  5. The problem of evil (evidential) suggests that (2) is not the creator.
  6. Therefore, the traditional arguments for God’s existence provide better support for the simulation hypothesis than they do for the traditional God of Theism.
I think the theist can challenge almost every premise here. Let's go through them in order

While premise (1) might apply to some arguments for God's existence (such as the fine-tuning argument), it seems obvious that it does not apply to many others, including some of the most popular in the current literature. For example, Rasmussen's contingency argument tells us that the creator must be a metaphysically necessary being, while his various stage-two arguments (if they succeed) tell us that it must be eternal, unlimited, unsurpassably powerful, and possessing a supreme nature. Similarly, the Pruss-Koons argument from basic natural facts seeks to establish the existence of a "supernatural being," that is to say, "a simple being that is unbounded and wholly infinite in intrinsic measure."

Premise (2) is uncontroversial (especially amongst theists), and so it seems like we can skip over that one.

Premise (3) seems to fail for the same reasons as premise (1); namely, the most popular theistic arguments today (such as the contingency argument) would seem to rule out a simulator. After all, a simulator would presumably be a natural being, rather than a supernatural one. We also have no reason to assume that they would be necessary, rather than contingent. In addition, stage-two contingency arguments (such as those made by Rasmussen) are specifically designed to solve the so-called "gap problem," by showing that the necessary being in question must have some or all of the traditional divine attributes.

Premise (4) fails for the same reasons as premises (1) and (3).

Premise (5) only works if one agrees that the problem of evil really does provide evidence against theism. However, even if one does agree with this, it seems like this premise still fails to support the simulation hypothesis. This is because, if my criticisms of premises (1) and (3) succeed, the traditional theistic arguments rule out the idea of a natural contingent being as the cause of our universe. 

The conclusion (6) stands and falls with the rest of the argument, so if (as I've argued) the rest of the argument fails, then so does (6).

I think Brown has also neglected an important point, namely that theistic arguments must be approached in tandem, rather than one-by-one. For example, assume that the argument from contingency is correct, and the existence of a necessary being has been established. Then when we consider the fine-tuning argument, we must take into account the fact that a necessary being exists. It would be deeply strange for there to be a necessary being which explains contingent reality, and also a fine-tuner who fixed the laws of nature. Therefore, any evidence that we have for design should be interpreted as evidence for design by the necessary being. But surely the traditional simulation hypothesis does not regard the simulating beings (whoever or whatever they are) as necessary. So Brown's argument would seem to fall flat yet again.

There is a potential way that one could escape this last argument: namely, one could hold that our world really is a simulation, but that reality as a whole was created by God. This view is not unheard of in the literature; David Kyle Johnson (2012) has argued that some theists might be committed to this view, while theists Barry Dainton (2020) and Dustin Crummett (2021) have both approached it as a potential theodicy. That being said, I don't personally endorse this view (nor am I one of those whom Johnson argues are committed to it), and I'm not sure how important it is for my above argument (since it is ultimately still a theistic view).

Monday, December 13, 2021

A New Paper on Physical Necessity

Alexander Roberts has published an interesting new paper in Mind, which argues for the claim that "those who believe in physical necessity should not harbour any scepticism towards merely metaphysical possibilities." How he reaches this result is quite complex, and I'll leave it to the full paper to provide an explanation; however, "the result requires those who believe in physical necessity to recognize merely metaphysical possibilities which are forbidden by our physical laws." The key line of argument in the paper revolves around the notion of lawless worlds (i.e. worlds in which no laws of nature, whether ours or any others, obtain). Roberts argues that such worlds are accessible from all other possible worlds by a finite chain of physical possibility.

Thursday, December 9, 2021

Contra Leon on Wave Function Realism

Felipe Leon thinks that wave-function realism should lead us to conclude that "ordinary perceptual experience is massively unreliable." He gives the following argument for this conclusion:

[It's] not at all clear how the ordinary three dimensions of our experience can be accounted for [given WFR]. In fact, some (e.g., Alyssa Ney) have argued that they probably can't, in which case there is non-trivial epistemic pressure to think the three dimensions of ordinary experience are, in an important sense, mirage-like.

Leon then argues that this leads to "troubling epistemic consequences for theism," because "if God exists, then God designed us in such a way as to ensure that our perceptual faculties reliably track the truth about the world." But if three-dimensional reality is illusory, then our perceptual faculties don't reliability track the truth, and as such, it is unlikely that God exists.

I think Leon is simply mistaken on this issue. To see why, take a look at this interview with philosopher of science Jill North (whom Leon also cites):

But ordinary 3-D space is not just an illusion, says North. “I think that 3-D space exists, and our talk about it is true. It’s just that this space is nonfundamental. Similarly, ordinary particles exist but are nonfundamental. They are more like tables and chairs: made up out of fundamental stuff, not themselves in the fundamental inventory.” 3-D space is a separate thing that is in some sense “made up out of” the higher-dimensional space, just as particles are ultimately “made up out of” the wave function.

Similarly, in a recent paper on wave-function realism and the place of 3D-space in a high-dimension world, Theodore Sider writes:

[High-dimensionalism] might suggest that rocks, trees, subatomic particles, and other three-dimensionalia are illusions, or intellectual mistakes, akin to phlogiston and phrenology, and should be purged from our cognitive lives. But high-dimensionalists cannot, and do not, take this hard line. In addition to being literally unbelievable, the view would be self-undermining. The empirical evidence for any scientific theory is three-dimensional, consisting of observations of pointer positions, computer readouts, and the like. If quantum mechanics implies that statements about pointer positions and the rest are all false, it does not imply any of our evidence, and thus it is incapable of empirical confirmation.

Accordingly, what high-dimensionalists say is not that three-dimensional matters are unreal, but merely that they are nonfundamental. High-dimensional fundamental reality “gives rise to” a nonfundamental three dimensional world. Thus high-dimensional quantum theories do, after all, imply facts about the three-dimensional evidence, and are therefore capable of confirmation.

Interestingly, Sider himself argues for a view on which high-dimensionalism is closer to what Leon supposes it to be (though he still accepts that our talk about 3D space is, in some sense, true). However, the point is that most defenders of higher-dimensionalism would reject the claim that 3D space is unreal.

As such, it seems that Leon is wrong to say that three-dimensional reality is "mirage-like." It may be nonfundamental, but it is not fictitious or unreal. This takes away most of the force from Leon's atheistic argument; after all, why should we expect God to give us accurate perception of fundamental reality? Isn't it enough that we perceive the level of reality on which we operate? One might as well say that our perceptions are misleading because we cannot see the individual atoms that make up the world around us!

Christopher Martin on Aquinas' Fifth Way

Christopher Martin provides an interpretation of the fifth way which I find rather plausible. He contends that “unconscious teleology is alw...