The God Delusion
Page 12
But why, in any case, do we so readily accept the idea that the one thing you must do if you want to please God is believe in him? What's so special about believing? Isn't it just as likely that God would reward kindness, or generosity, or humility? Or sincerity? What if God is a scientist who regards honest seeking after truth as the supreme virtue? Indeed, wouldn't the designer of the universe have to be a scientist? Bertrand Russell was asked what he would say if he died and found himself confronted by God, demanding to know why Russell had not believed in him. 'Not enough evidence, God, not enough evidence,' was Russell's (I almost said immortal) reply. Mightn't God respect Russell for his courageous scepticism (let alone for the courageous pacifism that landed him in prison in the First World War) far more than he would respect Pascal for his cowardly bet-hedging? And, while we cannot know which way God would jump, we don't need to know in order to refute Pascal's Wager. We are talking about a bet, remember, and Pascal wasn't claiming that his wager enjoyed anything but very long odds. Would you bet on God's valuing dishonestly faked belief (or even honest belief) over honest scepticism?
Then again, suppose the god who confronts you when you die turns out to be Baal, and suppose Baal is just as jealous as his old rival Yahweh was said to be. Mightn't Pascal have been better off wagering on no god at all rather than on the wrong god? Indeed, doesn't the sheer number of potential gods and goddesses on whom one might bet vitiate Pascal's whole logic? Pascal was probably joking when he promoted his wager, just as I am joking in my dismissal of it. But I have encountered people, for example in the question session after a lecture, who have seriously advanced Pascal's Wager as an argument in favour of believing in God, so it was right to give it a brief airing here.
Is it possible, finally, to argue for a sort of anti-Pascal wager? Suppose we grant that there is indeed some small chance that God exists. Nevertheless, it could be said that you will lead a better, fuller life if you bet on his not existing, than if you bet on his existing and therefore squander your precious time on worshipping him, sacrificing to him, fighting and dying for him, etc. I won't pursue the question here, but readers might like to bear it in mind when we come to later chapters on the evil consequences that can flow from religious belief and observance.
BAYESIAN ARGUMENTS
I think the oddest case I have seen attempted for the existence of God is the Bayesian argument recently put forward by Stephen Unwin in The Probability of God. I hesitated before including this argument, which is both weaker and less hallowed by antiquity than others. Unwin's book, however, received considerable journalistic attention when it was published in 2003, and it does give the opportunity to bring some explanatory threads together. I have some sympathy with his aims because, as argued in Chapter 2, I believe the existence of God as a scientific hypothesis is, at least in principle, investigable. Also, Unwin's quixotic attempt to put a number on the probability is quite agreeably funny.
The book's subtitle, A Simple Calculation that Proves the Ultimate Truth, has all the hallmarks of a late addition by the publisher, because such overweening confidence is not to be found in Unwin's text. The book is better seen as a 'How To' manual, a sort of Bayes' Theorem for Dummies, using the existence of God as a semi-facetious case study. Unwin could equally well have used a hypothetical murder as his test case to demonstrate Bayes' Theorem. The detective marshals the evidence. The fingerprints on the revolver point to Mrs Peacock. Quantify that suspicion by slapping a numerical likelihood on her. However, Professor Plum had a motive to frame her. Reduce the suspicion of Mrs Peacock by a corresponding numerical value. The forensic evidence suggests a 70 per cent likelihood that the revolver was fired accurately from a long distance, which argues for a culprit with military training. Quantify our raised suspicion of Colonel Mustard. The Reverend Green has the most plausible motive for murder.* Increase our numerical assessment of his likelihood. But the long blond hair on the victim's jacket could only belong to Miss Scarlet . . . and so on. A mix of more or less subjectively judged likelihoods churns around in the detective's mind, pulling him in different directions. Bayes' Theorem is supposed to help him to a conclusion. It is a mathematical engine for combining many estimated likelihoods and coming up with a final verdict, which bears its own quantitative estimate of likelihood. But of course that final estimate can only be as good as the original numbers fed in. These are usually subjectively judged, with all the doubts that inevitably flow from that. The GIGO principle (Garbage In, Garbage Out) is applicable here - and, in the case of Unwin's God example, applicable is too mild a word.
* The Reverend Green is the character's name in the versions of Cluedo sold in Britain (where the game originated), Australia, New Zealand, India and all other English-speaking areas except North America, where he suddenly becomes Mr Green. What is that all about?
Unwin is a risk management consultant who carries a torch for Bayesian inference, as against rival statistical methods. He illustrates Bayes' Theorem by taking on, not a murder, but the biggest test case of all, the existence of God. The plan is to start with complete uncertainty, which he chooses to quantify by assigning the existence and non-existence of God a 50 per cent starting likelihood each. Then he lists six facts that might bear on the matter, puts a numerical weighting on each, feeds the six numbers into the engine of Bayes' Theorem and sees what number pops out. The trouble is that (to repeat) the six weightings are not measured quantities but simply Stephen Unwin's own personal judgements, turned into numbers for the sake of the exercise. The six facts are:
1. We have a sense of goodness.
2. People do evil things (Hitler, Stalin, Saddam Hussein).
3. Nature does evil things (earthquakes, tsunamis, hurricanes).
4. There might be minor miracles (I lost my keys and found them again).
5. There might be major miracles (Jesus might have risen from the dead).
6. People have religious experiences.
For what it is worth (nothing, in my opinion), at the end of a ding-dong Bayesian race in which God surges ahead in the betting, then drops way back, then claws his way up to the 50 per cent mark from which he started, he finally ends up enjoying, in Unwin's estimation, a 67 per cent likelihood of existing. Unwin then decides that his Bayesian verdict of 67 per cent isn't high enough, so he takes the bizarre step of boosting it to 95 per cent by an emergency injection of 'faith'. It sounds like a joke, but that really is how he proceeds. I wish I could say how he justifies it, but there really is nothing to say. I have met this kind of absurdity elsewhere, when I have challenged religious but otherwise intelligent scientists to justify their belief, given their admission that there is no evidence: 'I admit that there's no evidence. There's a reason why it's called faith' (this last sentence uttered with almost truculent conviction, and no hint of apology or defensiveness).
Surprisingly, Unwin's list of six statements does not include the argument from design, nor any of Aquinas' five 'proofs', nor any of the various ontological arguments. He has no truck with them: they don't contribute even a minor fillip to his numerical estimate of God's likelihood. He discusses them and, as a good statistician, dismisses them as empty. I think this is to his credit, although his reason for discounting the design argument is different from mine. But the arguments that he does admit through his Bayesian door are, it seems to me, just as weak. That is only to say that the subjective likelihood weightings I would give to them are different from his, and who cares about subjective judgements anyway? He thinks the fact that we have a sense of right and wrong counts strongly in God's favour, whereas I don't see that it should really shift him, in either direction, from his initial prior expectation. Chapters 6 and 7 will show that there is no good case to be made for our possession of a sense of right and wrong having any clear connection with the existence of a supernatural deity. As in the case of our ability to appreciate a Beethoven quartet, our sense of goodness (though not necessarily our inducement to follow it) would be the way it is with a God and without
a God.
On the other hand, Unwin thinks the existence of evil, especially natural catastrophes such as earthquakes and tsunamis, counts strongly against the likelihood that God exists. Here, Unwin's judgement is opposite to mine but goes along with many uncomfortable theologians. 'Theodicy' (the vindication of divine providence in the face of the existence of evil) keeps theologians awake at night. The authoritative Oxford Companion to Philosophy gives the problem of evil as 'the most powerful objection to traditional theism'. But it is an argument only against the existence of a good God. Goodness is no part of the definition of the God Hypothesis, merely a desirable add-on.
Admittedly, people of a theological bent are often chronically incapable of distinguishing what is true from what they'd like to be true. But, for a more sophisticated believer in some kind of supernatural intelligence, it is childishly easy to overcome the problem of evil. Simply postulate a nasty god - such as the one who stalks every page of the Old Testament. Or, if you don't like that, invent a separate evil god, call him Satan, and blame his cosmic battle against the good god for the evil in the world. Or - a more sophisticated solution - postulate a god with grander things to do than fuss about human distress. Or a god who is not indifferent to suffering but regards it as the price that has to be paid for free will in an orderly, lawful cosmos. Theologians can be found buying into all these rationalizations.
For these reasons, if I were redoing Unwin's Bayesian exercise, neither the problem of evil nor moral considerations in general would shift me far, one way or the other, from the null hypothesis (Unwin's 50 per cent). But I don't want to argue the point because, in any case, I can't get excited about personal opinions, whether Unwin's or mine.
There is a much more powerful argument, which does not depend upon subjective judgement, and it is the argument from improbability. It really does transport us dramatically away from 50 per cent agnosticism, far towards the extreme of theism in the view of many theists, far towards the extreme of atheism in my view. I have alluded to it several times already. The whole argument turns on the familiar question 'Who made God?', which most thinking people discover for themselves. A designer God cannot be used to explain organized complexity because any God capable of designing anything would have to be complex enough to demand the same kind of explanation in his own right. God presents an infinite regress from which he cannot help us to escape. This argument, as I shall show in the next chapter, demonstrates that God, though not technically disprovable, is very very improbable indeed.
4
WHY THERE ALMOST CERTAINLY IS NO GOD
The priests of the different religious sects . . . dread the advance of science as witches do the approach of daylight, and scowl on the fatal harbinger announcing the subdivision of the duperies on which they live.
— THOMAS JEFFERSON
THE ULTIMATE BOEING 747
The argument from improbability is the big one. In the traditional guise of the argument from design, it is easily today's most popular argument offered in favour of the existence of God and it is seen, by an amazingly large number of theists, as completely and utterly convincing. It is indeed a very strong and, I suspect, unanswerable argument - but in precisely the opposite direction from the theist's intention. The argument from improbability, properly deployed, comes close to proving that God does not exist. My name for the statistical demonstration that God almost certainly does not exist is the Ultimate Boeing 747 gambit.
The name comes from Fred Hoyle's amusing image of the Boeing 747 and the scrapyard. I am not sure whether Hoyle ever wrote it down himself, but it was attributed to him by his close colleague Chandra Wickramasinghe and is presumably authentic.58 Hoyle said that the probability of life originating on Earth is no greater than the chance that a hurricane, sweeping through a scrapyard, would have the luck to assemble a Boeing 747. Others have borrowed the metaphor to refer to the later evolution of complex living bodies, where it has a spurious plausibility. The odds against assembling a fully functioning horse, beetle or ostrich by randomly shuffling its parts are up there in 747 territory. This, in a nutshell, is the creationist's favourite argument - an argument that could be made only by somebody who doesn't understand the first thing about natural selection: somebody who thinks natural selection is a theory of chance whereas - in the relevant sense of chance - it is the opposite.
The creationist misappropriation of the argument from improbability always takes the same general form, and it doesn't make any difference if the creationist chooses to masquerade in the politically expedient fancy dress of 'intelligent design' (ID).* Some observed phenomenon - often a living creature or one of its more complex organs, but it could be anything from a molecule up to the universe itself - is correctly extolled as statistically improbable. Sometimes the language of information theory is used: the Darwinian is challenged to explain the source of all the information in living matter, in the technical sense of information content as a measure of improbability or 'surprise value'. Or the argument may invoke the economist's hackneyed motto: there's no such thing as a free lunch — and Darwinism is accused of trying to get something for nothing. In fact, as I shall show in this chapter, Darwinian natural selection is the only known solution to the otherwise unanswerable riddle of where the information comes from. It turns out to be the God Hypothesis that tries to get something for nothing. God tries to have his free lunch and be it too. However statistically improbable the entity you seek to explain by invoking a designer, the designer himself has got to be at least as improbable. God is the Ultimate Boeing 747.
* Intelligent design has been unkindly described as creationism in a cheap tuxedo.
The argument from improbability states that complex things could not have come about by chance. But many people define 'come about by chance' as a synonym for 'come about in the absence of deliberate design'. Not surprisingly, therefore, they think improbability is evidence of design. Darwinian natural selection shows how wrong this is with respect to biological improbability. And although Darwinism may not be directly relevant to the inanimate world - cosmology, for example - it raises our consciousness in areas outside its original territory of biology. A deep understanding of Darwinism teaches us to be wary of the easy assumption that design is the only alternative to chance, and teaches us to seek out graded ramps of slowly increasing complexity. Before Darwin, philosophers such as Hume understood that the improbability of life did not mean it had to be designed, but they couldn't imagine the alternative. After Darwin, we all should feel, deep in our bones, suspicious of the very idea of design. The illusion of design is a trap that has caught us before, and Darwin should have immunized us by raising our consciousness. Would that he had succeeded with all of us.
NATURAL SELECTION AS A CONSCIOUSNESS-RAISER
In a science-fiction starship, the astronauts were homesick: 'Just to think that it's springtime back on Earth!' You may not immediately see what's wrong with this, so deeply ingrained is the unconscious northern hemisphere chauvinism in those of us who live there, and even some who don't. 'Unconscious' is exactly right. That is where consciousness-raising comes in. It is for a deeper reason than gimmicky fun that, in Australia and New Zealand, you can buy maps of the world with the South Pole on top. What splendid consciousness-raisers those maps would be, pinned to the walls of our northern hemisphere classrooms. Day after day, the children would be reminded that 'north' is an arbitrary polarity which has no monopoly on 'up'. The map would intrigue them as well as raise their consciousness. They'd go home and tell their parents - and, by the way, giving children something with which to surprise their parents is one of the greatest gifts a teacher can bestow.
It was the feminists who raised my consciousness of the power of consciousness-raising. 'Herstory' is obviously ridiculous, if only because the 'his' in 'history' has no etymological connection with the masculine pronoun. It is as etymologically silly as the sacking, in 1999, of a Washington official whose use of 'niggardly' was held to give racial offence. But
even daft examples like 'niggardly' or 'herstory' succeed in raising consciousness. Once we have smoothed our philological hackles and stopped laughing, herstory shows us history from a different point of view. Gendered pronouns notoriously are the front line of such consciousness-raising. He or she must ask himself or herself whether his or her sense of style could ever allow himself or herself to write like this. But if we can just get over the clunking infelicity of the language, it raises our consciousness to the sensitivities of half the human race. Man, mankind, the Rights of Man, all men are created equal, one man one vote - English too often seems to exclude woman.* When I was young, it never occurred to me that women might feel slighted by a phrase like 'the future of man'. During the intervening decades, we have all had our consciousness raised. Even those who still use 'man' instead of 'human' do so with an air of self-conscious apology - or truculence, taking a stand for traditional language, even deliberately to rile feminists. All participants in the Zeitgeist have had their consciousness raised, even those who choose to respond negatively by digging in their heels and redoubling the offence.
* Classical Latin and Greek were better equipped. Latin homo (Greek antbropo-) means human, as opposed to vir (andro-) which means man, and femina (gyne-) which means woman. Thus anthropology pertains to all humanity, where androl-ogy and gynecology are sexually exclusive branches of medicine.