Sunday, November 15, 2009

My notes for the McGrath debate

Here are the notes I used for the debate with Professor Alister McGrath on the 29th October. I ended up only alluding to the second objection as I thought it too technical on the night.

Does the natural world point to God?

Cosmic fine-tuning arguments - that God provides the best, or even a half-decent, explanation of the character the natural world in which we find ourselves - face FIVE main types of objection.

I am going to briefly outline all five. But, I intend to rest my case on just the last two. So the first three will just be sketched out, and are merely for your information only.

FIRST OBJECTION. As Alister acknowledges in his book, the science on which fine-tuning arguments are based is by no means uncontroversial.

For example, some scientists believe there may well be a multiverse – a plethora of universes governed by a wide range of different physical laws. If there is a multiverse, then it’s not particularly unlikely that there should happen to exist a universe that has the Goldilocks property of being “just right” for life.

Even if there’s only one universe, a number of scientists in any case question whether there is only a very narrow range of physical parameters within which life can plausibly emerge.

Physicists including Victor Stenger, Anthony Aguire, and Craig Hogan have studied those universes that result when six cosmological parameters are simultaneously varied by several orders of magnitude, and have found that stars, planets and life can plausibly emerge within many of them.

According to these physicists, then, it simply is not true that there is only a very narrow set of physical parameters within which life can plausibly arise.

But still, let’s concede, for the sake of argument, that Alister is correct, and these physicists incorrect, about the science on which cosmic fine-tuning arguments are based.

SECOND OBJECTION. Even if there is only a very narrow set of physical parameters within which life might plausibly emerge, it doesn’t follow that the chances of the actual universe falling within these parameters is low. In fact, several philosophers reject the suggestion that we can even assign such a chance to the physical universe.

Take Professor Hugh Mellor of Cambridge University, who is an acknowledged expert on probability theory.

According to Mellor, there are two kinds of probability: epistemic probability and physical probability (or chance). Epistemic probability is, roughly speaking, the likelihood of something’s being true given the evidence. Suppose I am looking at a roulette wheel on which I can see the ball has landed on slot 26. For me, the epistemic probability that the ball is in slot 26 very high – I have overwhelming evidence that’s were it is because I can just see it there. On the other hand, the physical probability of the ball being there – by which I mean the chance of the ball landing there given the laws of nature and a certain specification of the conditions under which the ball was thrown into the wheel - is pretty low: only about one in 37.

Now when proponents of fine-tuning, such as Alister, insist the “probability” of the universe producing life is low, they clearly do not mean epistemic probability. The epistemic probability of life is very high – we can see it all around us. So the notion of probability proponents of fine-tuning are appealing to must, according to Mellor, be physical probability.

But then notice that if the physical universe is the only physical universe there is, it cannot have a physical probability.

The universe will only appear to have such a probability if we smuggle in a quasi-physical setting for its creation, supposing, for example, that the cosmological constants were fixed by something like the spin of a cosmic roulette wheel. So, concludes Professor Mellor, the fine-tuning arguments are just confused.

Other philosophers, such as Neil Manson, Elliot Sober, and also Timothy and Lydia McGrew (who incidentally, are religious) concur with that conclusion, for other, independent reasons.

Still, let us also concede, for the sake of argument, that Alister is correct, and these various objectors are all mistaken. Let’s suppose we can talk meaningfully about the chances of the universe having a life-producing character.

THIRD OBJECTION. Even if we concede that the probability of the universe having a life-producing character by chance is otherwise low, that still does not provide any significant support for the suggestion that some intelligence designed the universe that way, if either (i) the probability of such an intelligent being is itself very low (as Richard Dawkins suggests), or (ii) if the very idea of such a being actually makes no sense (as I am about to suggest).

Suppose I claim that there exists a special sort of chair – a chair that transcends physical reality, existing in a non-spatial, non-temporal way. You would rightly be sceptical. Not just because there is no evidence for such a chair, but because the idea of such a chair is nonsensical. In order for something to be a chair, it must have arms, legs, a seat, and so on, and these are features that require spatial extension. The idea of a non-spatial chair is just confused.

But is the idea of an intelligent cosmic designer any less confused? If this designer is the creator of space and time, then he exists, or existed, non-temporally. But how can an intelligent agent exist non-temporally? The concept of an agent is the concept of someone or thing with beliefs and desires on which they might more or less rationally act.

But just as the concepts of chair arms and legs are essentially rooted in a spatial context, and make no sense when applied outside it, so the concepts of belief and desire are essentially rooted in a temporal context, and make no sense when applied outside it.

For example, beliefs and desires are psychological states, and as such necessarily have temporal duration. They are held for periods of time. The idea of a non-temporally held desire makes about as much sense as a non-spatially extended chair leg.

The concept of design is also essentially rooted in the temporal. You draw up a design, and then you subsequently realize it – a temporally ordered sequence of events. If the design does not precede the realization, then it was not designed at all.

So far as I can see, then, talk of some sort of super-agent or designer transcending time and space is just so much gibberish, like talk of a non-spatial chair.

We have taken a concept with which we are familiar – a chair, or an intelligent designer – and projected into a realm where its application no longer even makes sense. That’s not profundity. That’s meaningless twaddle.

But let’s suppose that even this third class of objection – which includes both Dawkins’s objection, and this objection concerning meaningless twaddle - and can be overcome.

Let’s just sweep all three categories of objection to one side. There still remain two more. It is on these last two – the fourth and fifth objections - that I rest my argument that the natural world does not “point to” God.

FOURTH OBJECTION. It is a huge leap from the conclusion that the universe is the product of an intelligence to the conclusion that this intelligence is the all-powerful and limitlessly benevolent God of love that Christians worship.

As the Templeton-prize-winning physicist Paul Davies points out at the end of his book The Goldilocks Enigma, even setting aside all the other difficulties, (I quote)

“The other main problem with intelligent design is that identity of the designer need bear no relation at all to the God of traditional monotheism. The “designing agency” can be a committee of gods, for example. The designer can be a natural being or beings, such as an evolved super-mind or super-civilization existing in a previous universe, or in another section of our universe, which made our universe using super-technology. The designer can also be some sort of superdupercomputer simulating this universe. So invoking a super-intellect…is fraught with problems.”

Davies is correct, of course.

Alister’s supposedly fine-tuned features, even if they did point towards a designer, no more “point towards” the existence of the Christian God than they point towards the universe being a computer-generated Matrix-type simulation, or the creation of an earlier super-civilization.

Which of course they don’t really “point to” at all.

FIFTH OBJECTION. I come now to my final, and most important, objection to the suggestion that the natural world points towards anything remotely like the Christian God.

It seems to me that, unlike the suggestions that the universe was designed by an earlier super-civilization, or superdupercomputer, the suggestion that the universe was designed by Alister’s God is just straightforwardly empirically falsified.

There is abundant empirical evidence that, if even if the universe was designed, it was not designed by the particular deity Alister believes in.

I am talking of course about the evidential problem of evil.

Last week I watched an episode of the BBC TV series Life. At the end of the programme, one of the cameramen was interviewed, and I was struck that he said that, after just a few weeks on the job, he was already considering of giving up wild-life photography because it was too emotionally harrowing – he was struggling to cope with the extraordinary degree of suffering the creatures he was filming were going through. That kind of suffering – appalling suffering, on a vast, global scale – has been going on, not just for two weeks, but for many hundreds of millions of years, long, long before we humans made our very recent appearance.

And of course, we humans suffer too. Consider a not uncommon occurrence [EDITIED: I have removed this second example as touches on matter in which I have some personal involvement and do not want posted on the internet).

Perhaps the universe is the product of an intelligence. I don’t think that’s likely, but even if it were, surely it is pretty obvious that the intelligence in question is not the Christian God of love – in all his limitlessly powerful and benevolent glory.

If you think that’s not obvious, well, consider another possible cosmic designer – suppose there is just one god – a supremely powerful and evil being. His cruelty and malice and know no bounds.

How likely is that? I am sure you will agree it is an absurd suggestion. Why – because it is straightforwardly empirically falsified by the enormous amounts of good that there are in the universe. Why would an evil God create love, laughter and rainbows? Why would he allow us to reduce suffering?

In short, just as, if you believe in a good God, you face the problem of evil, so if you believe in an evil God, you face the problem of good.

Because of the problem of good, it is clearly absurd to suggest that the natural world points towards an evil God.

But then why isn’t it equally absurd to suggest that natural world points to a good God?

Alister’s position, it seems to me, is like that of someone who wanders into a concentration camp, notes the stoves designed to provide meals and warmth and the mattresses designed for sleeping on, and concludes that not only was this camp designed by an intelligence with some interest in sustaining human life, it actually “points towards” a wonderfully loving and benevolent designer

The truth is, not only does the available empirically evidence not point towards the camp having such a wonderfully benevolent designer, it actually points very firmly away from the camp being the creation of any such being.

Ditto the universe.

13 comments:

Kosh3 said...

I think you mean D H Mellor? I think the point is a bad one - if you include for epistemic probability among the background information considered by the subject the fact that life exists, then it becomes trivial that the epistemic probability of the universe supporting life is very high - but this is simply the so-called 'problem of old evidence'. You can have epistemic probability that does not include amongst background information the fact that life does already exist in our universe, and that should be how we properly treat it.

Kosh3 said...

Oh they are the same person. I should have guessed the H stands for Hugh

Paul Crowley said...

Really excellent - the fine tuning argument is I think the hardest one to pick apart in debate, and this really does the job.

In the same way that God gets the credit for the good things but not the blame for bad things, God is predictable when the predictions have already come to pass but unknowable when things go the other way. So the fact that the Universe can sustain life is evidence for Him because that's what we'd expect Him to do, but the fact that nearly all of the Universe is incredibly hostile to life is not a strike against him, because he's all unknowable and we can't hope to second-guess him in this way.

The usual counter to your first objection is that multiverses violate Occam's Razor. Of course this is nonsense - Occam's Razor dictates against complexity, not size, or a theory that said that the Universe was at least billions of light years across and contained 70 billion trillion stars would not be able to get off the ground.

Kosh3: No, what you're talking about is exactly the physical probability, or as I prefer to call it the "model probability" ie the probability your model would assign it. And I can't find anything in what you say that gives me a legitimate way to assign a probability to physical law being the way it is.

Kosh3 said...

"Occam's Razor dictates against complexity, not size, or a theory that said that the Universe was at least billions of light years across and contained 70 billion trillion stars would not be able to get off the ground."

Increasing the number of entities postulated by a theory increases ontological complexity, as opposed to theoretical or syntactic complexity. Simplicity is not just one thing, and we ideally want to keep it down across the board.

"Kosh3: No, what you're talking about is exactly the physical probability, or as I prefer to call it the "model probability" ie the probability your model would assign it."

Even if you're correct, we can call it Juniberry probability for all that it matters: including the fact that life exists in the universe among our background information renders the probability estimation trivial.

"And I can't find anything in what you say that gives me a legitimate way to assign a probability to physical law being the way it is."

Probably (no pun intended) precisely because I didn't say a thing about ways to assign a probability to physical laws.

Anonymous said...

There is also the biological objection against the fine tuning argument.

Life evolves based on the conditions present. The universe isn't fine-tuned for us, we are fine-tuned for the universe!

Within reason, there are other conditions where other types of life may have evolved probably using different chemistry and radically different from us.

We are the way we are because of our physical reality and evolutionary history, not because the entire universe was changed to suit these forms.

DSurber said...

One other point to add to the fine tuning argument is that the science is far from definitive. Most physicists find the fine tuning objectionable and hope for a theory that eliminates the need. This is not to say that the universe is not fine tuned, but rather that just because our current model of the universe requires it to be does not make it so. Our current model could be (and most likely is) wrong.

And I still don't find the "meaningless twaddle" argument at all convincing. A chair that exists outside of space and time makes sense if we assume that outside of our universe there exists a different UNIVERSE with its own SPACE and TIME. Just like our universe exists outside of the Asteroids video game universe and our space and time exist outside of Asteroids space and time. Real asteroids exist in our universe that transcend the space and time of the Asteroids universe. I see no problem with a chair that exists outside our universe that transcends our space and time.

This of course runs into an infinite regress problem, but then all cosmologies seem to run into either an infinite regress or something unknowable. Occam's Razor stands us in good stead here.

kazdragon said...

And you got the God of Eth in there too. Nicely done.

Martin said...

Seems like a lot of words to tackle a delusion. Are you sure you are not feeding the delusion instead?

By the way, I noticed your non-spatial chair has one leg shorter than the others. It gives it a wobble. I suggest you slide a theoretical book under there to give it some stability.

bobius said...

Is there somewhere online where we can view this debate?

Stephen Law said...

Unfortunately permission not forthcoming...

bobius said...

Does that mean you won ;-)

robertslee01 said...

this article has many holes. with regard to the question of evil, it assumes that a Creator is responsible for the evil that exists in this world. Last time I checked, people are the ones doing bad things. We have been given a choice, and unfortunately some people have chosen to do evil. To blame that on God is a cop-out.

solomon said...

We cannot say 'does the natural world points to god". We should instead say "does the created world points to god". The answere is an absolute yes.