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As I explained in my last posts (one, two), I’m expecting good things from the upcoming dialogue between Sean Carroll and William Lane Craig. Here, I’ll look at a species of the cosmological argument for the existence of God known as the contingency argument.

Before all that: Sean has linked to my previous post about this debate. Just to be clear, I don’t think Sean needs much advice. I’m really using these posts as an excuse to discuss Carroll’s ideas. He knows the arguments, knows the cosmology, has a clear idea about what naturalism is and how to defend it, and is an excellent public speaker. Carroll’s arguments are interesting and relevant, and Craig’s response won’t be anything as basic as “here’s a Grammar 101 lesson on using terms of negation and indefinite pronouns.”

Long post ahead. The short story: Carroll needs to make clear his objection to the Craig’s version of the principle of sufficient reason. In particular, why think that the universe is an exception (perhaps the only exception) to the general trend that things exist for a reason?

Craig’s Version of the Argument

The cosmological argument for the existence of God has been defended through the ages by a who’s who of thinkers: Plato, Aristotle, Al-Kindi, Ibn Sina, Al-Ghazali, Maimonides, Aquinas, Scotus, Spinoza, Leibnitz, … Of course, it has also been critiqued, most famously by Hume and Kant. The debate continues. Craig’s version of the contingency argument goes like this.

  1. Everything that exists has an explanation of its existence (either in the necessity of its own nature or in an external cause).
  2. If the universe has an explanation of its existence, that explanation is God.
  3. The universe exists.

It follows from these premises that God exists (homework). Note that this argument has nothing to do with whether the universe has a beginning.

Some atheists (Lawrence Krauss in particular) object to the second premise, thinking that God is just crowbarred in, an ad hoc assumption. But premise 2 has its own argument:

4. Since the universe is the totality of space, time, matter and energy (i.e. that’s the sense of universe being used here), the cause of the universe must be spaceless, timeless, and immaterial.
5. The most plausible immaterial kind of thing that could cause a universe is a mind.
6. A spaceless, timeless, and immaterial mind that causes the universe deserves to be called God.

Premise 5, in turn, has its own argument based on the causal effeteness of abstract entities. If you want to go after premise 2, you need to deal with this argument. Krauss didn’t.

Getting slightly ahead of myself, Carroll seems to object to Premise 1. This premise is a version of the infamous Principle of Sufficient Reason (PSR). It is a mild version, applying only to things, not to all (contingent) truths. Craig argues for premise 1, or at least that the universe is not an exception to premise 1, as follows.

  1. It would be arbitrary for the atheist to claim that the universe is the exception to the rule. Merely increasing the size of the object to be explained, even until it becomes the universe itself, does nothing to remove the need for some explanation of its existence.

Alexander Pruss has advanced arguments for a version of the PSR along these lines. (I’m paraphrasing, dangerously).

8. If the universe could exist without explanation, then it would be inexplicable why just anything couldn’t exist without explanation. In other words, why is only the universe an exception to premise 1?
9. Universal principles are simpler than principles that apply to an arbitrary subset. The simplest explanation of fact that contingent things typically have explanations is that all contingent things have explanations.

Carroll’s Case

Let’s consider with what Carroll’s response might be, as gleaned from this reply to an op-ed piece by Paul Davies.

“[A]t first glance, it seems plausible that there could be [an] answer to the question of why the laws of physics take the form they do. But there isn’t. At least, there isn’t any as far as we know, and there’s certainly no reason why there must be. The more mundane “why” questions make sense because they refer to objects and processes that are embedded in larger systems of cause and effect. … The universe (in the sense of “the entire natural world,” not only the physical region observable to us) isn’t like that. It’s not embedded in a bigger structure; it’s all there is. We are lulled into asking “why” questions about the universe by sloppily extending the way we think about local phenomena to the whole shebang. What kind of answers could we possibly be expecting? … [The correct possibility seems to be] that’s just how things are. There is a chain of explanations concerning things that happen in the universe, which ultimately reaches to the fundamental laws of nature and stops. This is a simple hypothesis that fits all the data; until it stops being consistent with what we know about the universe, the burden of proof is on any alternative idea for why the laws take the form they do.”

Let’s break it down. Lurking in the background of this entire discussion is this question: what makes an explanation an ultimate explanation? What is it about this explanation that makes another iteration of “and why?” out-of-bounds? Carroll’s argument seems to be:

10. Chains of explanations have to end somewhere.
11. Once we arrive at a simple explanation that fits all the data, there is nothing to be gained by going any further. Such an explanation should be considered an ultimate “stopping-point” explanation.
12. The fundamental laws of nature are just such an explanation for the physical universe.
13. Thus, we should consider the fundamental laws of nature to be the ultimate explanation of the universe.

Carroll’s formula of “simplicity + fits the data” needs a closer look. (more…)

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I don’t know who Rob Sheldon is, but he doesn’t know much about cosmology. He recently was quoted in this post at uncommondescent.com regarding the geometry of the universe. If I lecture cosmology this year, I’ll set this passage as an assignment: find all the mistakes. It gets more wrong than right. I have an article for “Australian Physics” on common questions about cosmology that I’ll post here once it’s out (a fortnight, maybe). In the meantime, I’ll try to clear up a few things.

The discussion of the mathematics of curvature (flat, positive, negative) is about right. It’s when he discusses the universe that things go wrong.

It takes a lot of effort to find any curvature at all, and certainly it is difficult to get good agreement between different types of measurement.

Nope. That’s why it’s called the “concordance model of cosmology” – because the different measurements converge on the same set of cosmological parameters. For example, this plot.

… a “closed” universe that collapses back down to itself …

A common error. In a matter and radiation-only universe, closed implies collapsing. A cosmological constant and/or dark energy changes this: closed vs. open no longer divides collapse vs. expand forever. Here is the plot you’ll need, from John Peacock’s marvellous Cosmological Physics.

… one would like it to have positive curvature to avoid infinities …

Flat and negatively curved universes can be finite. A flat 3-torus, for example, is finite, unbounded and has a flat geometry. Einstein’s general relativity constrains the geometry of the universe but not its topology. (more…)

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As I explained in my last post, I’m expecting good things from the upcoming dialogue between Sean Carroll and William Lane Craig. Before discussing the topic, a few comments about debating.

An awful lot of rubbish has been written about counteracting Craig’s diabolical debating; it’s actually pretty simple. When you speak, make a clear argument for a relevant conclusion. After he speaks, target specific premises of his arguments and explain why you think they are unlikely to be true. That’s it. It sounds simple, and it’s been done very effectively, but so many of Craig’s opponents can’t manage it.

Critics have said that Craig unfairly dictates the flow of the debate, keeping a stranglehold on the topic of his choosing. This doesn’t happen when his opponent keeps him busy. Austin Dacey and Keith Parsons are great examples. Craig won’t ignore your case if you make one, and it’s relevant. Give him something to respond to.

If you fail to make a case, Craig will have read your writings and be prepared to both make your own case for you and critique it. He did this to great effect against Rosenberg. If you fail to address his arguments, he will point this out and repeat them. He is justified in doing so because one often hears the refrain that “I’m an atheist because there’s no evidence for God”. To maintain that there is no evidence, one must be able to explain why the supposed evidence isn’t really evidence at all. As an analogy, one cannot reasonably claim that “there is no evidence that human beings walked on the moon” and not attempt to explain the Apollo 11 photographs and videos.

There is no excuse for debating Craig underprepared. You can listen to a debate from the early 1990’s and get most of his arguments. That said, you are better off reading an article rather than responding to a 20 minute summary. It’s best not to raise objections that he has already addressed in print, or even better, raise them in a way that also addresses his response.

Always go for the argument, never the man. If you’ve shown that Craig is mistaken, then it doesn’t much matter how he convinced himself of such falsehoods. Amateur anthropology/psychology/neuroscience – e.g. any sentence beginning with “human beings have a very strong cognitive bias to believe …” – is a waste of time. Just burn down his arguments; don’t toast marshmallows on the embers. Resist Bulverism!

Remember: critiquing is hard. That someone is wrong doesn’t make it easier. Step 1: understand. Step 2: critique. Here are a few resources. Feel free to add more in the comments.

Kalam Cosmological Argument

Contingency (Leibnizian) Argument

  • I think the most comprehensive presentation of Craig’s version of the argument is in his book “Reasonable Faith”. A shorter (and free) introduction is here.

  • Some of the “Questions of the week” shed more light on the philosophical issues that arise: 132, 190, 248, 329.

  • I recommend Alexander Pruss’ article on the Leibnizian argument in the Blackwell Companion to Natural Theology. Craig calls it “a must”, but be aware that it differs from Craig’s version in both content and style. In particular, Pruss defends a more comprehensive version of the principle of sufficient reason.

Fine-Tuning Argument

  • Again, the book “Reasonable Faith” is the best resource. A slightly older presentation is here.

  • Questions of the weeks that address the argument: 49, 63, 161, 313. In particular, Craig’s response to the multiverse, include the Boltzmann Brain problem: 14, 285.

  • For the scientific details of the argument, Craig relies a lot on the work of Robin Collins. Collins’ best presentation of fine-tuning cases is in this book. He presents the argument itself in the Blackwell Companion to Natural Theology. He has an interesting discussion of the implications of the Boltzmann brain problem in this article.

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I’ve read two of Daniel Dennett’s books, and while I enjoyed them at the time I find myself unable to remember what they were about, what their arguments were, or indeed any memorable passages. Maybe it’s just me, but I remember almost nothing from “Freedom Evolves”.

I’ve just watched one of Dennett’s TED talks, having been pointed there by 3quarksdaily. The title of the talk is “The Illusion of Consciousness”. Maybe I’m being thick, but I after 20 minutes I’m left with this question: what does any of this have to do with consciousness at all, let alone showing it to be an illusion? Before I move on, I should stress that I’m no kind of philosopher of mind or neuroscientist. I’m not even particularly well-read in the popular literature of these fields. Comments, please!

What I’m going to try to do today is to shake your confidence … that you know your own, inner-most mind, that you are, yourselves, authoritative about your own consciousness. …

Somehow we have to explain how, when you put together teams, armies, battalions, of hundreds of millions of little robotic unconscious cells … the result is colour, content, ideas, memories, history. And somehow all that concept [content?] of consciousness is accomplished by the busy activity of those hoards of neurons.

So we’re off to a good start. The hard problem of consciousness is to explain why certain collections of cells become conscious at all. Dennett particularly wants to question whether we really know our own conscious selves. Good. What is his method?

How many of you here, if some smart alec starts telling you how a particular magic trick is done, want to block your ears and say, “I don’t want to know. Don’t take the thrill of it away. I’d rather be mystified. Don’t tell me the answer.” A lot of people feel that way about consciousness, I’ve discovered. I’m sorry if I impose some clarity, some understanding on you. You better leave now if you don’t want to know these tricks.

Method: condescension. He’s going to smug those illusions right out of us.

The example is wrong. I don’t want you to tell me how a magic trick is done for the same reason I don’t want the stranger on the train to lean over and give me crossword answers. It’s a puzzle. The fun is thinking about it yourself. No one says “I don’t want the crossword answers. I just want the mystery of the empty squares.”

Note the implicit ad hominem. Anyone who disagrees with Dennett is weak-minded, a blissful ignoramus. Actually, those who criticised books such a Dennett’s “Consciousness Explained” usually complained that it failed to explain consciousness.

I’m not going to explain it all to you. … You know the sawing the lady in half trick? The philosopher says “I’m going to explain to you how that’s done. You see  – the magician doesn’t really saw the lady in half. He merely makes you think that he does.” How does he do that? “Oh, that’s not my department”.

This is all very amusing, and delivered with a twinkle in the eye. But the message of the metaphor is this: brace yourself for some bald assertion. I’ll tell you what follows from my assumptions, but don’t expect any evidence.

(more…)

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Having had my appetite for the Middle Ages whetted by Edward Grant’s excellent book A History of Natural Philosophy: From the Ancient World to the Nineteenth Century, I recently read Edward Feser’s Aquinas (A Beginner’s Guide). And, on the back of that, his book The Last Superstition. If I ever work out what a formal cause is, I might post a review.

In the meantime, I’ve quite enjoyed some of his blog posts about the philosophical claims of Lawrence Krauss. This is something I’ve blogged about a few times. His most recent post on Krauss contains this marvellous passage.

Krauss asserts:

“[N]othing is a physical concept because it’s the absence of something, and something is a physical concept.”

The trouble with this, of course, is that “something” is not a physical concept. “Something” is what Scholastic philosophers call a transcendental, a notion that applies to every kind of being whatsoever, whether physical or non-physical — to tables and chairs, rocks and trees, animals and people, substances and accidents, numbers, universals, and other abstract objects, souls, angels, and God. Of course, Krauss doesn’t believe in some of these things, but that’s not to the point. Whether or not numbers, universals, souls, angels or God actually exist, none of them would be physical if they existed. But each would still be a “something” if it existed. So the concept of “something” is broader than the concept “physical,” and would remain so even if it turned out that the only things that actually exist are physical.

No atheist philosopher would disagree with me about that much, because it’s really just an obvious conceptual point. But since Krauss and his fans have an extremely tenuous grasp of philosophy — or, indeed, of the obvious — I suppose it is worth adding that even if it were a matter of controversy whether “something” is a physical concept, Krauss’s “argument” here would simply have begged the question against one side of that controversy, rather than refuted it. For obviously, Krauss’s critics would not agree that “something is a physical concept.” Hence, confidently to assert this as a premise intended to convince someone who doesn’t already agree with him is just to commit a textbook fallacy of circular reasoning.

The wood floor guy analogy is pretty awesome, so be sure to have a read.

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It’s always useful to know a statistics junkie or two. Brendon is our resident Bayesian. Another colleague of mine from Zurich, Ewan Cameron, has recently started Another Astrostatistics Blog. It’s well worth a look.

I’m not a statistics expert, but I’ve had this rant in mind for a while. I’m currently at the “Feeding, Feedback, and Fireworks” conference on Hamilton Island (thanks Astropixie!). There has been some discussion of the problem of reification. In particular, Ray Norris warned that, once a phenomenon is named, we have put it in a box and it is difficult to think outside that box. For example, what was discovered in 1998 was the acceleration of the expansion of the universe. We often call it the discovery of dark energy, but this is perhaps a premature leap from observation to explanation – the acceleration could be being caused by something other than some exotic new form of matter.

There is a broader message here, which I’ll motivate with this very interesting passage from Alfred North Whitehead’s book “Science and the Modern World” (1925):

In a sense, Plato and Pythagoras stand nearer to modern physical science than does Aristotle. The former two were mathematicians, whereas Aristotle was the son of a doctor, though of course he was not thereby ignorant of mathematics. The practical counsel to be derived from Pythagoras is to measure, and thus to express quality in terms of numerically determined quantity. But the biological sciences, then and till our own time, has been overwhelmingly classificatory. Accordingly, Aristotle by his Logic throws the emphasis on classification. The popularity of Aristotelian Logic retarded the advance of physical science throughout the Middle Ages. If only the schoolmen had measured instead of classifying, how much they might have learnt!

… Classification is necessary. But unless you can progress from classification to mathematics, your reasoning will not take you very far.

A similar idea is championed by the biologist and palaeontologist Stephen Jay Gould in the essay “Why We Should Not Name Human Races – A Biological View”, which can be found in his book “Ever Since Darwin” (highly recommended). Gould first makes the point that “species” is a good classification in the animal kingdom. It represents a clear division in nature: same species = able to breed fertile offspring. However, the temptation to further divide into subspecies – or races, when the species is humans – should be resisted, since it involves classification where we should be measuring. Species have a (mostly) continuous geographic variability, and so Gould asks:

Shall we artificially partition such a dynamic and continuous pattern into distinct units with formal names? Would it not be better to map this variation objectively without imposing upon it the subjective criteria for formal subdivision that any taxonomist must use in naming subspecies?

Gould gives the example of the English sparrow, introduced to North America in the 1850s. The plot below shows the distribution of the size of male sparrows – dark regions show larger sparrows. Gould notes:

The strong relationship between large size and cold winter climates is obvious. But would we have seen it so clearly if variation had been expressed instead by a set of formal Latin names artificially dividing the continuum?

(more…)

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The following table has appeared on my Facebook feed a few times.

599135_578921312126001_868557881_n

I have a few points to make in response. What follows is a critique of the table above, not of the Bible or Christianity. (more…)

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I’ve blogged before about my admiration for the remarkable talents of Derren Brown. However, I’ve just finished watching his latest TV offering, Fear and Faith, (Episode 2, first broadcast on Friday 16 November 2012) and I find it deeply flawed.

The show is pitched as an experiment. In particular, I’m going to discuss the segment in which “an atheist [Natalie] is given a religious conversion” via what Brown calls psychological techniques. The results of the experiment are very striking – I encourage you to watch the video, if you can.

Let’s begin by reminding ourselves of what an experiment is. Very simply, an experiment is a controlled attempt to link a particular cause to a particular effect. If you want to know whether morphine can relieve pain in humans, you might think that you just give people in pain morphine and then ask if the pain went away. However, this experiment cannot tell whether it was really the morphine that did it. Thus, we must use a control.

The idea of a control is to use two experiments that differ only in the presence or absence of what we’ll call the active ingredient. We must be able to control both the active ingredient and the other variables.  It is crucial that in every other way, the experiments are as identical as possible. In medicine, one crucial variable is the mental state of the patient, which is why the trial must be double blind – to factor out the placebo effect, patients and even their doctors cannot know whether the pill is real or fake.

Thus we come to Derren Brown’s experiment. I have four criticisms.

1. There is no control.

An effect is caused, but in the absence of a control, it isn’t clear to what it should be ascribed. This points to an even deeper problem.

2. The active ingredient is not supposed to be belief in God.

That one can produce a religious experience in the absence of belief in God is not an interesting conclusion. Plenty of religious people claim that a religious experience caused (and thus preceded) their belief in God. In fact, it would be much more embarrassing to the religious cause if religious experiences only happened in cases where the subject already believed in God, since that would make it seem as if the prior belief created the experience. Brown excludes this hypothesis.

3. The active ingredient is supposed to be God.

Tonight I’m going to investigate what I think could be the biggest placebo of them all – God. … This innate hardwiring we have really can give a powerful experience of God, without any need for Him to exist.

God himself (if you’ll allow the traditional masculine pronoun) is the active ingredient. Brown is claiming that he can create a religious experience in the absence of any action of God.

Let’s repeat the experimental logic, as we applied it to morphine (cause) and pain relief (effect) above. To adequately test the causal connection between religious experiences and God, Brown would need to control God. At the very least, he would need to perform an experiment in the absence of God. He would need to build a divine Faraday cage, to shield the possible effects of God.

Obviously, this is not what Brown has achieved. The experiment only proves that God is not required for a religious experience if there is no God, for only then is the active ingredient known to be missing from the experiment. Brown cannot exclude God as the cause of the experience without begging the question. The most he can claim is that he can do it “without mentioning God at all”. And that, clearly, is not the same thing. (more…)

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I’m going to jump back on one of my favourite high horses. I’ve previously blogged about Lawrence Krauss and his views on the question “why is there something rather than nothing?”. I’ve just finished his book, and he appeared last night on an Australian TV show called Q&A. It was a good panel discussion, but as usual the show invites too many people and tries to discuss too much so there is always too little time. Krauss’ discussions with John Dickson were quite interesting.

I’ll be discussing the book in more detail in future, but listening to Krauss crystallised in my mind why I believe that science in principle cannot explain why anything exists.

Let me clear about one thing before I start. I say all of this as a professional scientist, as a cosmologist. I am in the same field as Krauss. This is not an antiscience rant. I am commenting on my own field.

Firstly, the question “why is there something rather than nothing?” is equivalent to the question “why does anything at all exist?”. However, Krauss et al have decided to creatively redefine nothing (with no mandate from science – more on that in a later post) so that the question becomes more like “why is there a universe rather than a quantum space time foam?”. So I’ll focus on the second formulation, since it is immune to such equivocations.

Here is my argument.
A: The state of physics at any time can be (roughly) summarised by three things.

1. A statement about what the fundamental constituents of physical reality are and what their properties are.
2. A set of mathematical equations describing how these entities change, move, interact and rearrange.
3. A compilation of experimental and observational data.

In short, the stuff, the laws and the data.

B: None of these, and no combination of these, can answer the question “why does anything at all exist?”.

C: Thus physics cannot answer the question “why does anything at all exist?”.

Let’s have a closer look at the premises. I’m echoing here the argument of David Albert in his review of Krauss’ book, which I thoroughly recommend. Albert says,

[W]hat the fundamental laws of nature are about, and all the fundamental laws of nature are about, and all there is for the fundamental laws of nature to be about, insofar as physics has ever been able to imagine, is how that elementary stuff is arranged. (more…)

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I remember a technology TV show in the mid 90’s showing a roller coaster simulator ride. The audience is shown a simulation or video of the view out the front of a roller coaster, and the seats jostle and tilt in concert with the footage. I was only 11, but I concluded that it was the coolest thing ever.

Why they are almost convincing

There is a good physics reason why these rides are almost convincing. Galilean relativity says that inertial reference frames are indistinguishable using local experiments. In layman’s terms, if you are in an enclosed plane traveling in a straight line at a constant speed, then there is nothing you can do inside the cabin to work out how fast you are travelling1. The plane could be stationary or it could be doing a thousand miles per hour, and you won’t notice any difference between walking up the aisle and down the aisle.

In a car, we gauge speed by looking out the window and watching the scenery fly past. Ride simulators can simulate a fast moving roller coaster by showing a simulation of scenery going past. They also simulate the bumps and shunts by jostling your seat – the faster your car is going, the more you will feel the small deviations from uniform motion due to potholes.

I’ve been on a few of these rides, and I’m not fully sucked in. Speed is fine, bumps are fine, but the most exciting part of a real roller coaster ride is the “stomach in your throat” feeling as you go over a crest, or being thrown to one side as you take a corner at speed. Unlike speed, acceleration can be measured locally, so it can’t be simulated with a video and a shaky chair.

How to make them fully convincing

There is a way to simulate acceleration. Einstein’s equivalence principle roughly states that freely falling is locally indistinguishable from zero gravity. We can illustrate this point with a thought experiment. Suppose you wake up in an elevator which is freely falling (i.e. ignore wind resistance etc). There is nothing you can do inside the elevator to determine whether you are freely falling, or whether someone has turned off gravity2. If you want to know what it would be like if there were no gravity, then go jump off a cliff (in your mind, of course). (more…)

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