Fundamental Reality III: Chains, Parsimony, and Magic

Some optimistic folks hope that Science will eventually explain everything about the world.  But this hope seems absurd in light of the fact that explanations always involve presuppositions.  The structure of explanation is always that we explain one thing A in terms of some set of other things B, C, D... which exist, or which have happened.  (Let's not be too particular about what we mean by “things” here, whether “objects”, “events” or what...)  One could then ask what is the explanation of B or C or D, and these things will in turn typically have explanations in terms of other things.  This gives us various types of explanatory series, and we can ask whether these terminate in some type of ultimate explanation.

So it seems that the best we could possibly do is to have one thing or principle whose existence is unexplained, and then use that to explain everything else.  That one thing would then have no other explanation outside of itself.  However, we can still evaluate how plausible it is that it should exist, based on various considerations of parsimony.  We can ask:

  1. Is this entity the type of thing where it would make sense for it to just exist on its own?  Or is it the sort of thing that would more naturally be explained by reference to something else?
    .
  2. Is this the simplest conception of fundamental reality, or can we get away with a simpler one? (Here I am using simple in the sense of Occam's razor, although if there were really just one unexplained entity, not composed of parts, it would also be simple in the Medieval Scholastic sense of being non-composite.)

You might notice that the people of a scientific bent tend to focus exclusively on the second question, while traditional metaphysics focuses more on the first question.  In my view both questions are relevant.

I said that explaining everything in terms of one thing is the best we can do.  We might have to settle for less, such as a plurality (hopefully small) of unexplained fundamental principles.  However, that would not only be more complicated, it would also raise questions about what is it that joins these (supposedly separate) principles together.  We might therefore reasonably hope that the principles in question would at least have some type of internal unity, without being too dogmatic at this stage about what kind of unity we are looking for.

Some people might propose that the chain of explanations extends backwards forever in an infinite chain.  Thus nothing has any ultimate explanation, but rather each one is explained by the thing before it, and so on.  Alternatively one could have the explanations arranged in a circle, which is similar to the infinite regress for what I am about to say.

The chain of explanations wouldn't necessarily have to be embedded in any kind of temporal sequence, but if it were, one would have to have a universe which is eternal to the past.  Now there are physics problems with trying to make a compelling physical model along these lines, with neither a geometrical nor a thermodynamic type of beginning.  But here I'm trying to explore more general metaphysical considerations, of the sort that are accessible from the nearest armchair, so I'll try to appeal to intuition instead of esoteric quantum cosmology considerations, for which the evidence of a beginning is mixed.

Personally, I find an infinite regress, with nothing more behind it, rather unsatisfactory.  It is not that I think there is any logical inconsistency in a universe which extends backwards in time forever.  There isn't.  The universe might well work that way.  But I feel like such a chain of explanations wouldn't actually explain anything in the chain properly.  For example, in the “ekpyrotic” scenario where the universe involves an eternal bouncing back and forth of two membranes, it wouldn't tell us why there are two membranes rather than one or four.  It would just boil down to saying that: things just are the way they are because they are the way they are.  Of course, if there were some additional extra explanation outside of time which somehow determined that there had to be two membranes, that would be different, and would make me much more satisfied with a time that goes back forever.

Somebody might retort that explaining everything in terms of one unexplained thing is just as bad in that it also has something which “just is the way it is”.  But at least in that case it there's only one thing like that, not a whole chain of things.  I find in myself an intellectual preference for building explanations on a foundation.  Axiomatic reasoning is usually regarded as more intellectually respectable than circular reasoning.  If we deduce things from axioms, those axioms can be appreciated and evaluated.  Whereas if we deduce things from a chain going back to infinity, I feel that the entire system is unsupported in a vicious way.  So I'm fine with time going back to infinity, but only if there is something which transcends time which makes time do that.  Of course, Nature does not necessarily have to correspond to my intuitions, but I don't think it's irrational to believe that at least some of our intuitions give us rational guidance about how the universe should work.  Without some rational intuitions leading us to seek explanations, Science couldn't even get off the ground.

Furthermore, there are chains of explanation which do not go further and further back into the past, and these chains cannot be accounted for simply by postulating an infinite past.  We might also try to explain why the present-day dynamical processes of nature occur in the way that they do.  For example, suppose I want to know why a balloon attracts hair.  So I say it is because they have opposite electrical charges, which are attracted to each other with an inverse square law.  Well, why is that?  Well, because each charge has electric field lines coming out of it.  Why is that?  Because Gauss's equation said it had to happen that way.  Why is that?  It seems the answer must eventually be: it happens by MAGIC.

Some would say that this is obscurantism and that things happen because of the Laws of Nature.  But we have to remember that the phrase “Laws of Nature” is really a stand-in for whatever mysterious aspect of reality causes things to obey these Laws of Nature. When the phrase was first coined, the word “law” was a metaphor which was taken to imply the presence of a Legislator.  St. Chesterton suggests that the rational agnostic should instead use a different type of terminology, borrowed from fairy tales:

In fairyland we avoid the word "law"; but in the land of science they are singularly fond of it.  Thus they will call some interesting conjecture about how forgotten folks pronounced the alphabet, Grimm's Law.  But Grimm's Law is far less intellectual than Grimm's Fairy Tales.  The tales are, at any rate, certainly tales; while the law is not a law.  A law implies that we know the nature of the generalization and enactment; not merely that we have noticed some of the effects.  If there is a law that pick-pockets shall go to prison, it implies that there is an imaginable mental connection between the idea of prison and the idea of picking pockets.  And we know what the idea is.  We can say why we take liberty from a man who takes liberties.  But we cannot say why an egg can turn into a chicken any more than we can say why a bear could turn into a fairy prince.  As ideas, the egg and the chicken are further off from each other than the bear and the prince; for no egg in itself suggests a chicken, whereas some princes do suggest bears.  Granted, then, that certain transformations do happen, it is essential that we should regard them in the philosophic manner of fairy tales, not in the unphilosophic manner of science and the "Laws of Nature."  When we are asked why eggs turn to birds or fruits fall in autumn, we must answer exactly as the fairy godmother would answer if Cinderella asked her why mice turned to horses or her clothes fell from her at twelve o'clock.  We must answer that it is magic.  It is not a "law," for we do not understand its general formula.  It is not a necessity, for though we can count on it happening practically, we have no right to say that it must always happen.  It is no argument for unalterable law (as Huxley fancied) that we count on the ordinary course of things.  We do not count on it; we bet on it.  We risk the remote possibility of a miracle as we do that of a poisoned pancake or a world-destroying comet.  We leave it out of account, not because it is a miracle, and therefore an impossibility, but because it is a miracle, and therefore an exception.  All the terms used in the science books, "law," "necessity," "order," "tendency," and so on, are really unintellectual, because they assume an inner synthesis, which we do not possess.  The only words that ever satisfied me as describing Nature are the terms used in the fairy books, "charm," "spell," "enchantment."  They express the arbitrariness of the fact and its mystery. A tree grows fruit because it is a magic tree.  Water runs downhill because it is bewitched.  The sun shines because it is bewitched.

I deny altogether that this is fantastic or even mystical.  We may have some mysticism later on; but this fairy-tale language about things is simply rational and agnostic.  It is the only way I can express in words my clear and definite perception that one thing is quite distinct from another; that there is no logical connection between flying and laying eggs.  It is the man who talks about "a law" that he has never seen who is the mystic.
(Orthodoxy, "The Ethics of Elfland").

Let no one think that St. Chesterton said this only because he did not understand the particular explanations given by Modern Science.  He didn't, but it doesn't make any difference, since you come to the same place in the end no matter what.  No matter how many mediators we put in between the hair and the balloon—even if there is a continuum of mediating entities—at some point we need to postulate some sort of fundamental interaction not explained through intermediaries.

If we ask why these direct interactions occur, we either have to say for no reason at all (in which case it is a puzzle why things happen so consistently, since every single instance of an interaction would be a quite separate unexplained occurrence) or else to say that there is some common force or principle: either God or else some other term more acceptable to atheists.  We can call the underlying principle a “Law” if we want to (for lack of better language) but we should be aware that the word doesn't really explain why things had to be this way.

So in what follows, let's suppose that the explanations terminate on one or more unexplained entities, whether laws of physics, divinities or something else.  Because of the uncertainty about what these things actually are, I am not going to impose a rigid grammar on them, but will freely alternative between different terms.  I don't mean to sneak in any substantive assumptions by calling them “things”, “entities”, “principles”, “rules”, “beings”, or whatever.

Still, they must in some sense exist, or they couldn't do any work explaining anything else.  They are not merely logical abstractions, since logical abstractions can't do anything, they can only describe things.  Some people would say that it's a category error to say that laws can do anything, that laws merely describe regularities in Nature, but don't cause them to exist.  Well, if that happens to be true, then (contra Hume) something else must cause those regularities to keep occurring, otherwise it would just be a mighty coincidence that the regularities keep on happening.

In the following reflections I will try to say more about what this “something” might be.  I'm not trying to force a prematurely theological conclusion here.  I'm reasonably confident that any rational, complete worldview must have some set of fundamental entities or explanations which play the explanatory role that God does in Theism, but it is a quite separate question whether the thing(s) that fill that role have to be at all like the traditional conception of God.  This is a question which we will eventually need to face square-on, but first let's try to figure out some properties that any fundamental entities would have to have, no matter whether they are conceived of along Naturalist or Supernaturalist lines.

Next: Necessity, Eternity, and Power

Posted in Metaphysics, Theological Method | 5 Comments

Fundamental Reality II: Causes and Explanations

With sufficiently robust assumptions about how causation works, it is possible to formulate various Cosmological Arguments (there's more than one) in a strictly deductive way.  But in our age there isn't enough of a consensus about how causation works, or even whether it really exists, to create an argument with broad popular appeal.  Some people even say that Science has refuted the idea of causality and replaced it with other concepts.

Instead I'm going to go the long way around and focus on the concept of explanations.  It seems utterly clear to me that Science is in the business of finding explanations for certain phenomena.  If it can't do that, it loses any claim to make sense out of the world.  If you want your theory to explain even one single thing about the world, then that requires you to give an account of what circumstances explain that thing.  Then we say that the thing happened because of those circumstances.  And as you can see, that word “because” has the word cause sitting inside of it.  Grammar itself teaches us that Science requires some notion of causation.

For example, we say things like “the planets all rotate around the sun in the same direction because the solar system formed from a rotating disk of gas”, or “the heat capacity of matter is finite because it is made out of atoms”, or “electrons attract protons because they have negative charge”, or “energy is conserved because the laws of nature are invariant under time translation.”  It is not obvious that these various senses of “because” all correspond to the exact same concept, but we can take almost any of them as examples for what I am going to say.  (Except perhaps for the “because” of pure logical deduction from definitions, i.e. “cold is the absence of heat because that is what the word cold means; 2+2 = 4 because 4 is twice two.  But pure logic is not enough to explain everything that happens, since avoidance of strict logical inconsistency is a rather weak constraint.)

Aristotle famously said that there are four different types of causes: material, formal, efficient, and final.  As a classification of the types of "because" answers we give to various questions, this seems fairly reasonable.  But some people would argue that the physical sciences only use some of these types of explanations.  In particular, it is disputed whether final causes, which express purposes—e.g. that the sun exists in order to produce light, or that the animals eat in order to receive nourishment—really exist in reality outside of our own minds.  This question will pop up later when we discuss Ethics, not to mention the Fine-Tuning Argument.  For the time being, let's consider less controversial notions of causation, without assuming Aristotle’s division to be correct.

In order to side-step some possible misunderstandings about what I mean by an explanation, let me make it clear that I am using the term explanation in a broad sense, so that:

A. Explanations can be Nondeterministic.   An explanation does not need to be deterministic, in the sense that the effect invariably follows from the cause.  It is enough if the explanation produces a framework, in which it makes sense that the cause might be produced.  For example, Quantum Mechanics is a nondeterministic theory, in the sense that if you start with a given initial condition, and you know the laws of physics, there is generally more than one possible final outcome, and you can only predict their probabilities.  So long as the probability of what happens is not so low as to indicate that the theory is probably wrong, I'm going to count this type of thing as an explanation of the experimental outcome.  That's because it seems that the universe is not deterministic, and if it isn't, then probabilistic explanation is the best that we can do.

For example, if a radioactive atom decays, you can't predict exactly when it will decay, but you can still explain why it can decay with reference to the forces and particles in the nucleus.  It's not like the decay occurs in an explanatory void.  So I think in a quantum mechanical theory, we need to generalize our notions of "explanation" and/or "causation" to allow for such nondeterministic explanations.  Just because you can't predict exactly what happens, doesn't mean there isn't a set of circumstances which causes whatever does happens to happen.  It's just that there's more than one possible outcome that set of circumstances could have produced.  That's different from something happening without any causes at all.

B. Explanations can be Unknown.  Similarly, there obviously exist some phenomena which do have an explanation, but we don't know what it is yet.  In that case, I want the term “explanation” to refer to the actual reason why the thing occurs, and not merely to those explanations which are currently known to our limited human minds.  Maybe we will never find out the full explanation for something, but that doesn't mean it doesn't exist.  This point is important because Cosmological Reasoning, as I understand it, involves the attempt to push back the concept of explanation back to its ultimate fundamentals, to see what a fundamental explanation would have to look like in principle.  For example, a Naturalist doesn't necessarily need to know what the most fundamental theory of physics should look like, to propose that if we did know it fully, it would then explain everything else.

On the other hand:

C. Explanations are not just Regularities.  I reject the Humean view that causality is just a name for the constant conjunction of events.  In the end, I think this boils down to a renunciation of the possibility of explaining anything.  “Rocks have always fallen down before” is simply not an explanation for why the next rock falls down.  It doesn't have the right form to be an explanation.  It may make it rational to believe that the next rock will fall down, but the reason it does so is that we believe that there are underlying causes (in this case, gravitational attraction to the Earth) which remain roughly the same for each rock.  Conversely, there are many types of regularities (e.g. as of 2014, a woman has never been U.S. President) which may be unbroken in our experience, but that doesn't make those recurrences Laws of Nature.  Hence, when we seek to explain things, we ought to demand more than just the occurrence of regularities.

This seems to me to be elementary common sense, and I don't think the mathematization of physics (which merely describes these regularities, in increasing generality and detail) should change this conclusion.  But even if you accept the Regularity View, you still can't do Science at all unless you try to figure out how to describe these regularities with the most fundamental and deep laws possible.  On any reasonable view of causation, we can ask whether this process of explaining things finally terminates; and that will be the topic of the next section.

Next: Chains, Parsimony, and Magic

Posted in Metaphysics, Theological Method | 1 Comment

Fundamental Reality I: Prologue, or Why Even Bother?

Looks like I've got to tell you now what I think about the Cosmological Argument.  I believe that Cosmological Arguments can give us a good reason to believe in some type of fundamental entity which causes the universe to exist.  In Theism that fundamental entity is taken to be God.  However, I think that the Cosmological Argument by itself, apart from other considerations, does not necessarily imply either Theism or Supernaturalism.  That is because there are also candidates within Naturalism for what that entity might be.  But there are related considerations, having to do with consciousness and ethics, which in my view tip the scales towards Theism, and I will try to also explain what these are.

Before I begin, let me tell you right away that this isn't my preferred approach for doing Apologetics.  I generally prefer a more empirical approach based on examining historical records for things like, oh, people being raised from the dead.  That's not just because that type of data can potentially get you to Christianity instead of just Theism.  It's also because, as a scientist, I've been trained to prefer the data to purely theoretical reasoning. Also, as someone who has studied the history of Philosophy, I'm well aware of just how far astray one can be led by so-called “armchair reasoning”, where you try to figure out how it makes sense for the universe to work, based only on broad aspects of reality.

There's way too many examples of philosophers (I'm looking at you, Kant) who say that things logically follow necessarily from premises, when in fact they don't.  They're sneaking in extra assumptions on the side: relying on intuitions and then calling it Reason.  It's not irrational to have intuitions—without them reasoning would never get off the ground—but not everyone necessarily shares those intuitions.  That's just how it is in Philosophy.  Any strictly deductive arguments for the existence of God necessarily rest on premises that not everyone is going to accept.

So I'm not going to even try to make deductive claims for most of what I'm going to say, but instead I'll try to tell you why I find Theism plausible, from an armchair reasoning point of view.  There are plenty of places where you'll be able to dissent from me.  I will argue that Theism makes better sense out of the world than any rival view, but not that all other views are inconsistent or absurd.

The English idealist F.H. Bradley said that “Metaphysics is the finding of bad reasons for what we believe upon instinct; but to find these reasons is no less an instinct.”  Well, I'm going to indulge that instinct here. I'm well aware that what I say isn't going to convince everyone.

I've been told that the perfect philosophical argument would be one where if the hearer understood the argument but failed to accept the conclusion, they would just die.  The struggle to accept the incoherence would just be too much, and their brain would shut down.  Well, there aren't any arguments like that, but I think Metaphysics is still worth doing anyway.

In fact, we must do Metaphysics.  Even if you decide to focus on empirical evidence such as miracle claims, you still have to decide how much empirical evidence you actually need to accept a conclusion that may seem weird to you. But just how weird is God's existence? Bayes' Theorem says that the assignment of prior probabilities is a necessary step in evaluating any claim.

So that means, when deciding whether something exists or not, we always need to have some set of plausibility heuristics in our mind which say how likely that thing is to be.  In cases where we are talking about the fundamental nature of existence, that means we've got to do Metaphysics.  Even if there are no strictly deductive arguments (from indisputable premises), there are still going to be plausibility arguments pointing in various directions.  It's irrational to put too much faith in plausibility arguments, but it's also irrational to be completely insensible to them.  We must assess the plausibility of propositions in order to evaluate them properly.

If at any point you think I am handling things badly and going beyond my evidence, I ask only to be judged by fair standards.  It's easy enough to just take a negative point of view, and criticize unwarranted assumptions in other people's arguments.  But suppose that someone asked you to stand up and defend your own metaphysical beliefs (say, materialism) with arguments capable of persuading others.  Not just something offhand like “This makes sense to me, and I've never seen any good reason to believe otherwise”, but some robust intellectual argument for certain types of existence or nonexistence claims. You'll quickly find that it's a hard thing to do.  Yet some particular specific set of metaphysical statements must in fact be true, even if it is hard to see which ones.

So if you disagree, please do not just say, “There's a hole in your reasoning at line 278, therefore you are being illogical and religion is irrational.”  Instead tell me what metaphysical view you find more plausible and why.

From this perspective, I find it interesting that it is possible to argue for the existence of God as well as we can.  There are no compelling armchair arguments for the existence of quarks, jaguars, and so on, yet these exist and are observationally measurable.  Only in the case of the most fundamental being, God, can we make any kind of purely philosophical argument for his existence.  And that is precisely because he is so fundamental, that he is part of the background for everything else that we can or do experience.

I hasten to repeat that this type of considerations I'm about to present are not the primary reasons why I believe in God.  God has shown himself through explicit divine revelations, recorded in the Bible and elsewhere.  So it is not necessary to approach him through purely philosophical means. And there are many important things about God which we cannot hope to learn without revelation.  Nevertheless, there are some people who have argued themselves into Theism for reasons similar to those I am going to describe.  I also think it gives some helpful background motivations for Christian theology, even though it is not the primary source of it.

But I don't think Cosmological Argument type reasoning should be exclusively thought of as an argument for Theism, as though it had no other applicability except as a religious tool.  I think there are several different types of Cosmological considerations, and that anyone trying to think through Metaphysics seriously, will have to do some type of reasoning not completely unlike what I am going to say.  Indeed, quite a bit of what I am going to say should be acceptable even to atheists, and I would continue to accept several of the arguments even if I ceased to be religious.

None of what follows is intended to be particularly original, except for the presentation, and perhaps also the modesty with which I wish to assert the following claims as plausibility arguments, rather than any kind of strict deductions.  Broadly speaking, the types of arguments being considered have been around for a long time (longer than Christianity has been around), although I'm going to present them in the form I find most plausible even at the cost of a bit of originality.

One might worry that such arguments are a post hoc attempt to justify, through specious reasoning, conclusions which really came from certain religious texts.   But historically speaking, this is not at all what happened.  The arguments were developed primarily by Greek philosophers such as Plato, Aristotle, and the Stoics.  These arguments tended to support a monotheistic view of the world, which was actually in conflict with the polytheistic view of their surrounding culture.  (Other Greek philosophers developed something more akin to Naturalism, which was of course also in conflict with popular Greek religion.)  It is therefore quite interesting that the Greek arguments supported something much closer to the Hebrew conception of divinity, which the Hebrews had received by Revelation rather than Reason.  Western culture as we know it is really the synthesis of the Greek mind with the Jewish heart, without which there is no theo-logy.

But that combination is also not the origin of Christianity.  Rather, it is the cultural milieu in which Christianity started.  The compatibility of these two sets of ideas was just starting to be appreciated, when something far stranger than either of them came into the world to save it.

Next: Causes and Explanations.

(Update: edited the sentence about the perfect philosophical argument.)

Posted in Metaphysics, Theological Method | 13 Comments

Construct your own Cosmological Argument

First read this piece by St. Feser:
So you think you understand the Cosmological Argument?

about the traditional structure of Cosmological Arguments, rebutting several popular misconceptions.

Now take the following argument scheme, making suitable choices as needed:

  1. (Major Premise) Every [thing/event] with property X needs a [cause/explanation/reason] outside of itself to [cause/explain/be the reason of it]
    .
  2. (Minor Premise) There is at least one [thing/event] with property X.
    .
  3. (Inductive Principle) You have a choice...
    A.  argue that an infinite regress of [causes/explanations/reasons] for the X's is unreasonable, OR
    B. argue that such an infinite causal chain would itself have property X, OR
    C.  argue that the entire set of X's taken together (which might, depending on X, include the entire physical universe we know and love) has property X.
    .
  4. (Conclusion) Tracing back the [causes/explanations/reasons] back to their ultimate origin, we find that there is [one/at least one] thing which does not have property X, which, taken [singly/together], [causes/explains/gives the reason for] all the things which do have property X.
    .
  5. (Atheist Baiting) Add the famous words: "And this all men call God".  Works best if ~X is a traditional divine attribute, or even better if you can collect several such ~X's and can argue that they all refer to one and the same Exalted Being!

For example, in the debate, St. Craig's kalam argument used "comes into existence" as X, and then used a lumping strategy (3C) to talk about the universe as a whole and ask whether it had a cause.  This form of the Cosmological Argument ended up being strongly dependent on what the Science of the Big Bang actually shows, but most forms don't really depend that strongly on Science.

Other traditional X's include "changing with time", "contingent" (something that might or might not exist), "composite", and some other possibilities mentioned in the link above.   The idea is that there are some features of objects which make us seek out causes for them, for example if an object is composed of several disparate objects, we naturally want to know what brought them together.  Depending on what you pick for X, the Cosmological Argument may be more or less plausible.

You will also want to consider what type of causal concept you want to include in your argument.  A key question is how we know there is such a thing as causation?  If it is primarily for empirical reasons, then presumably we know about it through some type of inductive argument from experience, in which case we could wonder how applicable it will be in unusual situations.  On the other hand, if it is primarily motivated by reason, through analyzing what types of explanations would make sense of the universe, it may be less dependent on observation.  Or perhaps the truth is somewhere in the middle.

Another thing to figure out is what types of entities are connected by cause-effect relationships.  Does a cause have to determine the effect with certainty, or is it sufficient if it in some way produces it?  For example, if we want to argue that all contingent things were caused by something which is necessary, this is a contradiction in terms unless a necessary thing can produce contingent things, i.e. if causes don't have to be deterministic.  A related question: when we talk about causes, are we primarily talking about beings causing things to happen (a.k.a. agent-causation), or states of affairs causing things to happen (a.k.a. event-causation), or both?

Regarding step (5), note that excessively glib atheist baiting obscures the fact that nearly everyone should accept some type of Cosmological Argument, even if they don't necessarily take it to a Theistic conclusion!  If you are going to talk about causes/explanations/reasons AT ALL (and I really don't see how to avoid this) then you really need an account concerning the domain to which the concept is applicable.  And then it is an interesting fact, that either you must accept infinite or circular chains of [causation/explanation/reasons] or you end up going outside the domain to something else which is different.

This type of reasoning should be interesting, even if you are an atheist.  The trouble is, if people only encounter Cosmological Arguments in the context of Theism, then Atheists adopt an argumentative approach where they just feel the need to poke a few holes in the arguments and then retreat to where they were before.  This doesn't do justice to the fact that there are numerous X's for which the argument's premises are at least plausible, even for people who don't start out committed to any particular religious doctrine.

For example, Carroll himself gives an account of the scope of causation when he says:

Why should we expect that there are causes or explanations or a reason why in the universe in which we live? It’s because the physical world inside of which we’re embedded has two important features. There are unbreakable patterns, laws of physics—things don’t just happen, they obey the laws—and there is an arrow of time stretching from the past to the future. The entropy was lower in the past and increases towards the future. Therefore, when you find some event or state of affairs B today, we can very often trace it back in time to one or a couple of possible predecessor events that we therefore call the cause of that, which leads to B according to the laws of physics. But crucially, both of these features of the universe that allow us to speak the language of causes and effects are completely absent when we talk about the universe as a whole. We don’t think that our universe is part of a bigger ensemble that obeys laws. Even if it’s part of the multiverse, the multiverse is not part of a bigger ensemble that obeys laws. Therefore, nothing gives us the right to demand some kind of external cause.

There seem to be some question-begging moves in this paragraph, but leave that aside.  My point is that Carroll gives a positive account of when he thinks makes the notion of [cause/explanations] make sense.  He endorses a version of (1) whereby the concept of causation makes sense if (a) there are laws of nature, understood as unbreakable regularities, and (b) there is a thermodynamical arrow of time whereby entropy increases, making a distinction between the past and the future.  (Since causes normally precede effects, but the laws of physics don't strongly distinguish between the two directions of time except through thermodynamics, it seems clear that the arrow of time has to play some role in distinguishing causes from effects in physics.)

He also allows (2) that this concept—though not fundamental in his opinion—nevertheless makes sense for certain particular cases.

Then for (3) he allows us to lump together the universe taken as a whole, but claims that this whole does not meet his criterion (1).  He thus comes to an object—the whole universe, apparently—for which, in his view, it wouldn't make sense for it to have a cause (4), although he does not identify it with God (5).  Thus his reasoning has an implicit atheist version of the Cosmological Argument behind it.  Though one can certainly question whether the metaphysical assumptions behind this claim are right.

But it's just possible you came here hoping, not to construct your own Cosmological Argument, nor to deconstruct Carroll's, but instead to find out what I think about it, something which you may think I have postponed saying for quite long enough.  Well, it just so happens that I've written a 16,000 word essay on the Cosmological Argument and related topics, and will be posting it in installments over the course of the next few weeks.

Posted in Metaphysics, Reviews, Scientific Method, Theological Method | 40 Comments

Explanation needed

I've been discussing Sean Carroll's claim that:

The demand for more than a complete and consistent model that fits the data is a relic of a pre-scientific view of the world. My claim is that if you had a perfect cosmological model that accounted for the data you would go home and declare yourself having been victorious.

In my last post, Models and Metaphysics, I tried to argue that there are substantive philosophical questions about causality which Carroll is dismissing unduly as pre-scientific.

But in this post, I thought I'd give a concrete example of a situation where we would not declare victory and go home, even with a complete and consistent model of the universe.  While at some point fairly soon I'd like to give my own take on the Cosmological Argument, my counterexample in this post isn't going to depend on any seriously heavy-duty metaphysics.  Instead I'd like to try to focus on something fairly quantitative and precise, something  "rational almost to the verge of rationalism", in short, an argument that even someone steeped in scientism could love.

Let's imagine that in the future, we come up with a seeming Theory of Everything™ which explains almost everything about the world.  Every single physical phenomenon which has ever been observed has now been explained by a simple equation.  Let us stipulate that the initial state of the universe is itself determined by these equations, leading to a cosmology consistent with what we observe.  If you like, we can also pretend that no supernatural events have ever been verified, and that (after the Great Riot of 2438 C.E., when all the metaphysicians and philosophers were confined to the tops of their Ivory Towers and forbidden to communicate with the ordinary citizens outside) we have all agreed not to inquire to closely into the question of why certain physical states of the brain correspond to conscious experiences.  It is indeed a great triumph for the Scientific Method.

There's one catch.  The remaining (non-meta)physicists tell us that there is one universal constant of nature in the theory, designated by a capital alpha A, whose numerical value needs to be fixed before any predictions can be made.  This constant is dimensionless, meaning that all the units cancel out, so that it isn't measured in meters per gram, or joule-seconds, or anything like that, but is just a real number.  For example, it might be the ratio of two things with the same units.  Because this constant A is dimensionless, it's numerical value is independent of the choice of units used to measure this parameter.

(In real life there are currently about 26 or so dimensionless constants in the Standard Model plus General Relativity—not counting inflation or dark matter—the most famous of these constants being the fine structure constant, which is approximately 1/137.036\ldots.)

Since the equations work equally well no matter what the value of A is, we have no choice but to do experiments to see what its value is.  Let us suppose (rather unrealistically) that the scientists have measured this parameter to 800 decimal places, and that—lo and behold!—the answer is exactly

A = \frac{2\pi}{7}.

No one knows why, that's just the way things are. 

(Note: this situation is different from the usual Fine-Tuning Argument, because I am not supposing that there is any reason why life requires the constant to take on this precise value.)

I submit to you that, notwithstanding the fact that this TOE™ gives a complete description of everything in the universe, we ought not to declare victory and go home.  Because it is plain as day that this number 2\pi / 7 requires some sort of explanation which has not yet been given.  In other words, we don't just demand that our models completely explain the data.  We also demand that they be complete in the sense of providing explanations for anything which seems to require an explanation.

True, 2\pi / 7 is not an extremely complicated number; in most computer languages one can write a fairly short computer program that spits out this number.  But I didn't become a physicist in order to compress my sense-data into as few bits of information as possible; WinZip does a better job of data compression than I ever could.  I became a physicist in order to understand how and why the world works the way that it does.

So I wouldn't be completely satisfied with this TOE™ as it stands, even though it would be a big improvement on our current best theories of physics.  Instead I would start asking naïve questions like:

"Why is there a 2\pi in the formula for A, given that we all know that 2\pi is the ratio between a circle's circumference and its radius?  Where do circles come into it?"

and

"What's so special about 7?  Is this just a random whole number that was pulled out of a hat?!?  Why is the denominator even an integer at all?  What is 7—a sufficiently awkward prime that it seldom comes up in physics formulae—doing in the most fundamental equation of the universe?"

Now I don't know whether all of these mutterings about sevenths of circles would get me shoved up a Tower or not.  But I am convinced that this question would be meaningful, that it must have an answer, and that any red-blooded human being with basic curiosity about the world should hope to find the answer.

Or, to speak in Bayesian terms, nearly all of my prior probability would be placed on there is an explanation for this odd fact that I don't know yet, and nearly none on this is just an inexplicable basic fact about the universe which has no explanation at all.  I'm not sure how to convey this intuition to you if you don't already share it.  But it seems to me that basic inexplicable facts about the universe shouldn't fall into patterns which seem to indicate the existence of a deeper layer of reality, unless there actually is a deeper layer of reality behind the shadows we see on the cave wall...

"What's that? Yes officer, I was just headed for that Tower over there right now!  Please don't let me trouble you any further.  No, I just stepped out for a moment.  Yes.  Look I'm heading back right now.  See?"

Of course, just because I would think that there must be an explanation, doesn't mean that we would ever find out what that explanation is.  Life can be a bummer that way:

All this I have proved by wisdom.
I said, “I will be wise”;
But it was far from me.
As for that which is far off and exceedingly deep,
Who can find it out?
(Ecclesiastes 7:23-24)

I would be potentially open to any explanation involving either "natural" or "supernatural" elements, so long as it in fact explained the parameter.

Of course, if the explanation involved more ad hoc elements than the thing being explained, then that would raise questions about whether it was really the best or simplest explanation.  And even if I thought of a good explanation, I might wonder if there were some other equally good explanation. Or conversely, I might not be able to think of any good explanation at all.  So at the end of the day I might have to be an agnostic about what type of explanation should be considered.

But that wouldn't change the fact that I'd think there'd be one.

Posted in Metaphysics, Reviews, Scientific Method, Theological Method | 5 Comments