Swinburne Chapter 6: The Explanatory Power of Theism

Swinburne pauses for breath here, and goes over Bayes’ Theorem once again. He repeats the original formulation

P(h|e & k) = [P(h|k)P(e|h & k)] / P(e|k)

Where

P(h|e & k) is the probability of the existence of God, given all the various bits of evidence we will come to,

P(h|k) is what he calls the intrinsic probability of God (i.e. the probability before we consider the evidence),

P(e|h & k) is the probability that the evidence would be as it is, given that God exists,

P(e|k) is the intrinsic probability of the evidence.

He expands this last term (correctly) as follows

P(e|k) = P(e|h & k)P(h|k) + P(e|~h & k)P(~h|k)

The first term is the same as the top line of the equation. The second is the converse, i.e. the probability that the evidence would be as it is, given that God does not exist, multiplied by the intrinsic probability of God’s nonexistence.

So overall we get the following equation

P(h|e & k) = [P(h|k)P(e|h & k)] / [P(e|h & k)P(h|k) + P(e|~h & k)P(~h|k)]

Now, if it is a while since you last did any maths & algebra at school, all these letters and symbols might look a bit intimidating. Of course, they are intended to look that way. So let me show you how the theorem actually works on a more down-to-earth example.

Suppose that at a particular a school, 60% of the pupils are boys, and 40% are girls. There is a school uniform, and all the boys must wear trousers, but the girls have a choice between trousers and skirt. A quarter of all the girls choose to wear trousers. You see a child in the distance wearing the school uniform, and can see that the child is wearing trousers. What is that probability that the child is a girl?

We use precisely the same equation.

P(h|e & k) is the probability that the child is a girl, given the evidence of wearing trousers. This is what we are trying to calculate.

P(h|k) is the prior probability that the child is a girl. We know that number, it is the proportion of girls in the school, i.e. 40% or 0.4.

P(e|h & k) is the probability that any particular girl wears trousers. We know this is 0.25.

P(e|~h & k) is the probability that a boy wears trousers. This is 1, since all boys must wear trousers.

P(~h|k) is the prior probability that the child is not a girl. We know this is 0.6, because we know that 60% of the children in the school are boys.

So we have all the numbers we need, and can plug them into Bayes’ equation.

P(h|e & k) = ( 0.4 x 0.25 ) / [ ( 0.4 x 0.25 ) + (1 x 0.6 ) ]

Get the pocket calculator out (or multiply it out in your head), and it comes out at 1/7, or about 14%.

You can check this out by another method. Out of every 100 children, 60 will be boys, and 40 will be girls. Of the girls, 10 wear trousers, and 30 wear skirts. We aren’t interested in the skirt-wearing children – we can see that the child has trousers. Of the trouser-wearing children, 60 are boys, and 10 are girls. So 10 out of every 70 trouser-wearing children are girls, or 1/7.

You can extend this to cover multiple pieces of evidence. For instance, taking the above example, suppose that 80% of the girls in the school have long hair and only 10% of the boys, and you can see that the child in the distance has long hair and is wearing trousers, you can make the calculation simply by plugging the new numbers into Bayes’ theorem. First, you calculate for the trouser-wearing (as shown above). That gives you a new set of prior probabilities, for the probability that a trouser-wearer is a boy or a girl. Our new evidence is the long hair. Modify the definitions above, replacing trousers with long hair, and plug the numbers into the equation. We now get this

P(h|e & k) = ( 0.14 x 0.8 ) / [ ( 0.14 x 0.8 ) + ( 0.1 x 0.86 ) ]

0.14 is the proportion of girls among trouser-wearers, and similarly 0.86 is the proportion of boys (i.e. 1 – 0.14). 0.8 is the proportion of girls with long hair, 0.1 is the proportion of boys with long hair.

Calculate this out, and it turns out that the chance of a long-haired child wearing trousers being a girl is about 0.57, or 57%.

How can that be? The chance of any trouser-wearer being a girl was only 14%! Well, by being aware of this new piece of evidence, we can now eliminate from consideration a much larger proportion of the children i.e. all the short-haired ones.

We can check it out using the other method as well. We previously worked out that for every 100 children in the school, there were 70 trouser-wearers, of whom 10 were girls. 8 out of 10 girls have long hair, but only 6 out of the 60 boys have long hair. So among the long-haired trouser-wearers, 8 out of every 14 are girls, i.e. 57%.

And that in essence is what Bayes’ theorem is all about. There is a whole load of algebra which I shan't bother to go into here which shows why Bayes' theorem works. If you're interested in probability and statistics you shouldn't just take my word for it, I recommend that you look up the maths and understand it for yourself. But the fact is, Bayes' theorem does work.

What Swinburne hopes to do is to make estimates of the various probabilities regarding God, feed them into Bayes’ theorem, crank the handle and produce an overall probability for God’s existence.

In the previous chapter, Swinburne was trying to make an assessment of the prior probability of God’s existence, which he called the intrinsic probability of theism. In the example of the schoolchildren described above, we know the prior probability that any particular child is a girl. We know that because we know how many girls and how many boys are at the school, we can simply count them. Even when we can’t count an entire population, we can sample it – that is what opinion polls are all about. And with that sample we can get a fairly accurate estimate of probabilities which can be fed into Bayes’ theorem.

But we don’t have a population of gods, nor do we have a population of universes, some of which have been made by God and some of which haven’t. We have a hypothesis regarding the existence of just a single God, and evidence in the form of just one universe whose existence we know of. And yet, Swinburne wants to make use of Bayes’ theorem in order to assess the “balance of probability” of God’s existence. In order to do that, he will have to put a number on each of the following concepts.

1. The prior probability of God’s existence
2. The probability of God’s existence given each of the various “pieces of evidence” that he puts forward (the cosmological argument, the teleological argument etc)

In the previous chapter, Swinburne was working his way towards suggesting a figure for P(h|k), the prior probability of God’s existence. Even to describe it in those terms is to show the futility of the effort. Either God (by Swinburne’s definition) exists or he doesn’t, and scientific investigation should in principle be able to uncover evidence one way or the other. For instance, if God performs miracles, we might reasonably hope that one or two of them would happen while scientists have their instruments pointed in the right direction. Because Swinburne’s hypothesis is not looking for what proportion of all gods have a particular set of characteristics, there isn’t any way of expressing it as a numerical probability.

The same applies to the various conditional probabilities he is looking to assign numbers to. We know what proportion of girls at the school wear trousers, we can count them. In a larger population, we could sample. Either way, we would have a statistical method by which we could come up with a number. But how can we estimate the probability of whether God would make the universe the way it is, if he exists? There is only one way available, and that is quite simply to make the numbers up.

And that is what Swinburne does, though he disguises the fact under a huge torrent of words. By the end of this chapter, we have been through 132 pages of argument which describe Swinburne’s reasons for saying that it is justified to make up the numbers, and on what basis he will choose one number over another. In the latest chapter he describes various reasons for thinking it probable that God would want or need to create a universe containing humans. I’ll paraphrase it rather than directly quoting. He thinks that it is a good thing that humans exist, and since God is perfectly good by definition, creating humans is the sort of thing that we might reasonably expect God to do. God might also want to create animals as well, but there isn’t such a good reason for him to want to do that, so animals don’t tip the matter much one way or the other. Swinburne then for the first time in the book goes on to actually assign a number which will get plugged into Bayes’ equation. This really is worthy of direct quotation.

I have argued in this chapter that there is a modest probability intermediate between 1 and 0, to which I will give the artificially precise value of 1/2, that a God will create humanly free agents located in a beautiful physical universe, perhaps also containing animals.

If you understand probability and statistics it is possible to decode this. It means that by his own admission none of his arguments are sufficient to make any kind of estimate of probability in the matter (it's impossible by definition to have a probability outside the range 0 to 1, so he is in fact ruling nothing out at all), but because he needs a number in order to proceed to the next chapter, he's going completely arbitrarily to decide to use 1/2.

Yes, that really is how he proceeds.

Meeting with Abbot Shipperlee of Ealing Abbey

I spent a little over an hour with Abbot Martin Shipperlee on Friday morning, discussing issues arising out of Fr David Pearce’s conviction on charges of sexual assault and indecent assault.

The Abbot was aware of my blog, and I made it clear from the outset that I would write down my impressions of the meeting. He told me that Fr Pearce is to be sentenced on October 2^nd, and a public statement will be made then, and that there would be some things he couldn’t say now in a discussion with me because they would pre-empt that public statement. I think that is fair enough, it is obvious to me that a further public statement must be made then, and we can only wait to see what it contains. Furthermore, my blog is not an appropriate vehicle for formal public statements from the Abbot about the case.

I started out by presenting to him the comment from the anonymous abuse victim. Although he had read the blog, it was before that specific comment had been put up, so he hadn’t seen it. I pointed out that this was (to the best of my knowledge) an entirely characteristic reaction to abuse of this kind. It is very difficult to come forward, and the pain doesn’t go away. I pointed out that this being so, it is certain that there are more victims who haven’t yet come forward, and who perhaps may never do so. It is very likely that these greatly outnumber the victims he is so far aware of. I also commented that while the anonymous commenter and I agree about the non-existence of God, I regard it as an absolute tragedy that somebody should be driven to that belief as a necessary psychological survival mechanism. He didn’t disagree with any of that.

We then looked at the public statements as they were reported in the local papers at the conclusion of the civil case in 2006 and on the occasion of Pearce pleading guilty to the criminal charges last month.

At the conclusion of the civil trial, the Ealing Times included the following in its report.

In a statement written to parishioners and obtained by the Ealing Times, Abbot Martin Shipperlee from Ealing Abbey said: "A High Court judgement was given against Fr David Pearce and Ealing Abbey, and damages awarded to a former pupil of our school.

"In addition, allegations relating to 1984 have been made against Fr Stanislaus Hobbs, and he has now been charged with an indecent assault."

He added the Abbey "deeply regrets" anything which could have led to such allegations being made, and said the incidents were being investigated in "full co-operation" with the diocese and police in accordance with the recommendations of Lord Nolan's report on the protection of children in the church.

Both Fr Pearce and Fr Hobbs have been relieved of any ministry and are currently away from the monastery.

The Ealing Gazette included this in its report on Fr Pearce’s criminal trial.

Westminster RC diocese said: "Ealing Abbey is deeply saddened by the case."

I have quoted above the sum total of the church’s statements as included in the two reports.

I asked him whether these reports were a reasonable representation of what had in fact been said, or whether they had misrepresented him or the church in any way. He agreed that they were a fair summary of the statements given at the time, and that there was no misrepresentation. He said that the statement following the criminal trial was as brief as it was because the criminal case doesn’t actually end until sentence is passed, and so his full statement will come then.

I then described the impression that those statements had had on me when I first read them. I said that they sounded like weasel words. He initially bridled somewhat at the phrase, saying that they were truthful words.

I explained that they sounded like he was being extremely careful to be as unspecific as possible about what exactly he was regretting. I said that it could easily be interpreted as regretting that the case had come to light, but not actually regretting the harm that Fr Pearce had done, since he didn’t offer any description of that harm. I said that whether or not that was what he intended to convey, or whether he thought the way I received the words was fair or not, that was an honest description of how it came across to me, and that it was entirely likely that others will have formed the same impression.

I made a comparison with confession, that a true and valid confession cannot be made until the sinner has a full understanding of what he has done wrong, and that once that full understanding has been achieved, the confession has to avoid the use of euphemisms and circumlocutions that minimize the magnitude of the sin. The use of euphemisms is a sure sign that the repentance is not genuine. I said that the same applies to apologies, and that anybody who has suffered at the hands of Fr Pearce will treat any apology that uses euphemisms as an insult and as a sign that the apology is not genuine. I commented that statements such as have been provided to the press so far quite probably serve only to increase the pain of the victims.

He promised to take my thoughts into account when preparing his statement for October 2^nd.

During the conversation, we both repeatedly caught ourselves slipping into the use of euphemisms to describe the abuse.

We then moved on to the question of whether he is now in fact in a position to know what has been done wrong. By this, I meant not only the extent of the abuse perpetrated by Fr Pearce, but also the actions (and inactions) of the Abbot and others which resulted in Fr Pearce continuing unchecked for so many years, and the full extent of the harm that has been caused to the victims of abuse. In other words, I asked whether he is yet in a position to fully understand what he has to apologise for.

I asked what had been done (aside from the criminal investigations) to review the past and uncover the extent of the abuse. This merged into the next issue that I wanted to discuss, the measures being taken to prevent any repetition of the abuse, and particularly to ensure that any reports are promptly acted on so that any abuse gets stopped immediately instead of being given a chance to continue.

First of all he acknowledged his past failures. Quite clearly, the measures he had taken when he first received reports of abuse had been insufficient. He acknowledges that he had believed himself competent to act to bring an end to the abuse when with the benefit of hindsight he clearly wasn’t. He had thought that the steps he had taken to prevent a continuation of the abuse would be effective, and clearly they failed.

He said that the procedures have now been changed, such that for instance whenever there is a report of abuse, the police are now brought in immediately. We didn’t go into detail of what precise changes have been made. I saw little point as I’m not an expert in the field and therefore not competent to carry out an audit.

So I asked instead if he had requested or received external expert assistance in reviewing the Abbey’s and schools’ procedures for child protection. Agencies external to the Abbey have been brought in. He briefly described to me the Catholic Safeguarding Advisory Service and the National Catholic Safeguarding Commission, and told me that both had been in to review procedures and policies. He said that changes have been made and there is still much work to be done to make sure that the policies are not only implemented but that everyone involved is used to effectively operating them. He said that the work of these two bodies is being carried out on a systematic basis though the whole of the Catholic Church in this country.

I pointed out a major problem of perception. It may be that those organisations are extremely effective in what they do, or they might not. I have no way of telling. But both are Catholic organisations, set up to be part of and to provide a service specifically to the Catholic Church. Given that the failures of the church to prevent and respond to sexual abuse are tragically common and widespread, with horrifying cases popping up all over the world, many people will understandably have grave doubts as to the church’s ability to reform itself by turning to organisations set up by the very church in need of reform.

In addition, I pointed out there has been a highly public and major failure resulting in great harm to children in the church’s care, which has happened on Abbot Shipperlee’s watch here in Ealing. Even if the two organisations he mentioned are doing an effective job, for him to earn a restoration of trust requires more. In my view, it requires that he go an extra mile beyond what the rest of the church is doing, and call in non-Catholic secular agencies who are experts in this field to provide an independent review and report. Otherwise, many people will understandably think the various church agencies are colluding in a cover-up. I said that I didn’t know who would be the best people to do that review, but that a phone call to the NSPCC to discuss it might be a good starting point from which he could find out.

Abbot Shipperlee didn’t promise to do that. He said that in this context he perhaps had not yet given adequate thought to the need not only to set things right but also to be clearly seen by the outside world to do so, and that this was an issue that he needed to reflect on further. He saw where I was coming from and accepted that the idea had merit, but felt that since he hadn’t thought this through sufficiently, he wanted time to reflect before deciding, and so he didn’t feel able instantly to say that he would go ahead and do this.

We then discussed the matter of providing care and support to the victims. One of my objectives in giving him that comment right at the start was to fix in his mind the fact that there are almost certainly very many victims who are at present unknown to him, who through shame or disgust or fear have not come forward, or who were unaware of the criminal investigation and so did not make a statement to the police. If Fr Pearce’s abuse started in 1972, the victims are hardly going to be restricted to the five boys he has been convicted of assaulting.

I also expressed the opinion that the letters he has sent to parents of the Abbey’s schools and the statement he has made at Mass cannot be regarded as public apologies, since many of the victims will have moved away from the parish or even left the church in disgust, and so would have been in no position to hear the apology, no matter how heartfelt and sincere it was. (By the way, I don’t yet know what form of words he used in his statement in Mass or the letters to parents. He has promised to forward a copy of both to me. Since again it would pre-empt his October statement, I am not going to publish them here even once I receive them.) Once children leave the school, they scatter to the four corners of the earth, and if the abuse has been going on at least since 1972, there are undoubtedly a far greater number of victims amongst ex-pupils than among those still attending the school. Apologies read out at Mass and notices posted on the boards in the Abbey don’t constitute an effective way of reaching out to those victims. I pointed out that modern technology, in the form of the web, offers a means of reaching out that simply wasn’t available to past generations, that an apology on the Abbey website has the scope to reach far more past pupils than the efforts made so far.

His response to this was that it simply hadn’t occurred to him to do that. He said that on reflection he has concentrated too closely on himself and Fr Pearce and the actions necessary to stop the abuse, and on the victims he is in contact with and for whom support is being provided. He wasn’t specific about what this support was, and out of consideration for the privacy of the victims I did not ask for details. He acknowledged that on reflection too little has been done so far to offer support to victims as yet unknown.

Finally, I asked about his motivations, whether in his public statements so far he could with complete honesty say that the care and support of the victims was his primary concern, or whether trying to salvage the good name of the church was also in his mind. He was surprisingly slow to answer. He acknowledged that in retrospect, concern for the reputation of the Abbey was one of the matters on his mind, and that the statements as they have been reported in the press have not adequately communicated concern for the victims, partly because he himself did not make it sufficiently clear, and partly because the message has been attenuated through the medium of newspapers who have other agendas. I replied that concern for the Abbey’s reputation is also concern for the Church’s reputation, and that the Abbey’s reputation deserves to be no better than is justified by the actions of its clergy, and that his expressions of concern for the victims and tangible actions to help them form part of that reputation. He agreed.

I closed by saying that I was in no way convinced that all would be well, and that I would be following the situation with interest. I said that I would far prefer that the Abbey learned and was able properly to protect those in its care, but that if I concluded that this wasn’t happening, I would have no hesitation in calling for the Abbey to sever its links with the schools if thought that would better assure the safety of the pupils. I said that I might wish to visit again in a few months to discuss progress with him, to which he agreed.

===========================

I wrote up the notes above as soon as I returned home. I then decided the leave them overnight and review them again and make any necessary additions or corrections that I spotted. It isn’t a verbatim transcript of the discussion, but it is an account of the meeting which is as honest and accurate as my memory permits. I took notes of a few specific items during the meeting (the names of the organisations called in to help refine the child protection policies), but in order to keep the conversation going, I decided not to attempt to take notes of everything else during the meeting. I’m not a journalist and I don’t have shorthand.

I’ve deliberately avoided as far as possible mixing my opinions as to the Abbot’s responses in with the narrative, except in as far as I provided responses to him at the time. I felt it better to put my opinions down separately here at the end, so as to give people the opportunity to form their own impressions first.

I found the discussion somewhat frustrating. He was very cagey in many of his replies, and there was no means by which I could tell whether this caginess was simply for the reason he gave (that he cannot pre-empt the public statement he will give when Fr Pearce is sentenced) or whether there was some other reason as well.

He said the sorts of things I would expect to hear if he was essentially a good man trying to do his imperfect best to rectify a terrible situation, one brought about in part by his own failures in trying to do things he was unqualified for. But they are also exactly the sorts of things I would expect to hear from a person who is looking to restore the good name of the church by telling people what he thinks they want to hear. And until I see the actions, I have no way of knowing which of those two possibilities is nearer the truth, or whether it is in fact all a bit of a muddy mixture of the two.

Given the catastrophic extent and the duration of the Abbey’s failure to protect the children under its care from a monk and priest under the Abbot's authority, I don’t think that he can fairly expect to be given the benefit of the doubt. For the Abbot and the Abbey to regain public trust, fine words are needed, but even more important is that they are matched – and seen to be matched – with fine actions.

I left the meeting quite tired and feeling somewhat angry, for reasons I couldn’t quite put my finger on. Having read through my notes, I think I now recognise the source of that anger.

In describing his failures to stop Fr Pearce earlier, Abbot Shipperlee was of course stating no more than is blindingly obvious to anybody with a passing familiarity with the case. What he said was fine as far as it went, but it didn’t actually go very far.

And this is symptomatic of what I see as the main problem, the true source of my anger. It is that the scope of the Abbot’s actions so far seem always to have been as narrow as possible, and aimed at dealing with the most immediate problem.

• His original actions to try and bring an end to Fr Pearce’s abuse were kept within the church, and as far as I can tell were aimed solely at preventing future abuse and not aimed at punishing past abuse or at identifying or supporting victims. And what is more, they didn’t even succeed in that limited aim.
  
• His public statements have focussed solely on the immediate issues at hand, and have been restricted to a relatively narrow audience in most cases.
  
• He appears to have done no more than is now being required across the whole Catholic Church to put in place procedures to prevent and halt future cases of abuse.
• He appears to have shown little or no curiosity regarding the wider picture – how far has the abuse extended, who else might have been involved, how many people have been harmed, how can they be helped.
  

I was most shocked about his response to the idea of putting something up on the website to reach out to scattered victims. If he were lying, and had up to now made a conscious decision to try and let sleeping dogs lie and not reach out to victims so far unidentified, then that would be a terrible betrayal of the idea that Christians should conduct their lives so as to be a witness to the love of Christ. On balance, I think it overwhelmingly probable that he was not deliberately lying to me. He struck me as a person who would find it difficult to tell a deliberate and outright lie.

But it is not all that much better if he is telling the truth and that the idea of trying to use the website to reach out beyond the current parishioners and parents simply didn’t occur to him. The Abbey already has a website, the existence of which he can hardly be unaware. It contains material concerning matters such as messages to prospective new parishioners and to people considering a vocation as a monk. It provides a weekly letter from the parish to all who wish to read it, and the text of the week’s homily. It has a regularly-updated notice board concerning parish events. In other words, the website is already attempting to reach out beyond the boundaries of the parish.

For it not to occur to the Abbot to use the website as a means of reaching out to victims of Fr Pearce is an extraordinary failure of imagination. He put it down to being an elderly cleric who is not all that up-to-date with the developments of the world. On reflection, I find that excuse to be hard to swallow. If he’s that out-of-touch with the world, he is hardly a fit person to have responsibilities concerned with the running of a school which is preparing children for their place in that world.

From the criminal case we know that the abuse started at least as early 1972. That is the date of earliest crime to which Fr Pearce has pleaded guilty. I don’t know when Fr Pearce first joined the Abbey or started teaching at St Benedict's School, but if it was some time before 1972, I think it unlikely that the police have managed to successfully prosecute the very first case of indecent assault that Fr Pearce ever committed. And it is beyond belief that the cases which have come to court are anything other than a very small proportion of all the assaults and other abuses Fr Pearce has committed. The oldest of his victims are quite probably now in their 40s or 50s, and they could be living anywhere in the world.

No, I’m not satisfied. Not by a long chalk.

Swinburne: The Intrinsic Probability of Theism

In Chapter 5, The Intrinsic Probability of Theism, Swinburne looks again at the definition of the theistic God and adds more detail to it, and then makes his assessment of its prior probability in terms of how simple he finds the conception of God to be.

Whether you agree or not with Swinburne’s idea that a simple concept has a higher prior probability than a complex one (I don’t, because the concept of prior probability is meaningless in this context), it is worth examining this concept of simplicity. All the evidence of the universe available to us is that complex things develop slowly through natural processes from simpler ones. This applies not only to life through evolution, but apparently also to the relatively complex present structure of the universe from simpler beginnings. So even though I find Swinburne’s talk of prior probability entirely misguided, there is still the point that the start of the universe apparently needs to be something simple.

Let’s take a look at what Swinburne thinks of this, starting with Swinburne’s understanding of God

There exists now, and always has existed and will exist, God, a spirit, that is, a non-embodied person who is omnipresent. … In essence, to say that God is disembodied is to deny that there is any volume of matter such that by his basic actions he can control only it and such that he knows of goings-on elsewhere only by their effects on it. By contrast, to say that God is an omnipresent spirit is to say that he knows about goings-on everywhere without being dependent for that knowledge on anything, and can control by basic actions all states of affairs everywhere (in this or any other universe) without being dependent for that power on anything. God is creator of all things in that for all logically contingent things that exist (apart from himself) he himself brings about, or makes or permits other beings to bring about, their existence. He is, that is, the source of the being and power of all other substances.

Clear enough. According to his hypothesis, God created everything, is everywhere, and can do anything not logically contradictory. He then goes on to justify this in terms of simplicity, in order to claim that the hypothesis that there is such a being has a high prior probability.

To start with, theism postulates a God who is just one person, not many. To postulate one substance is to make a very simple postulation.

Quite why one is simpler than zero is not stated. But never mind. Let us continue.

He is infinitely powerful, omnipotent. This is a simpler hypothesis than the hypothesis that there is a God who has such-and-such limited power (for example, the power to re-arrange matter but not to create it). It is simpler in just the same way that the hypothesis that some particle has zero mass, or infinite velocity is simpler than the hypothesis that it has a mass of 0.34127 of some unit, or a velocity of 301,000 km/sec. I finite limitation calls out for explanation of why there is just that particular limit, in a way that limitlessness does not.

I must say that Swinburne is being very selective here. He claims that there must be a limit to human understanding of the universe, and that the existence of this limit doesn’t need explanation, but that there is no limit to the powers of God, and this lack of a limit also requires no explanation. In fact, anything that he chooses to posit appears to require, by definition, no explanation.

As I noted in chapter 3, scientists have always preferred hypotheses of infinite velocity to hypotheses of very large finite velocity, when both were equally compatible with the data. There is a neatness about zero and infinity that particular finite numbers lack.

This is simply ignorant. Swinburne is trying to claim scientific justification for his hypotheses without having taken the trouble to find out how scientists actually think. Scientists haven’t always preferred infinities and zeros and they don’t today. Since Swinburne is keen on talking about Newton and gravity, let us note that Newton himself was extremely bothered by the fact that the action of gravity by his equations appeared to operate at infinite speed – and yet the equations didn’t work for a finite speed for gravity. Newton wrote the following to a colleague in 1692.

“That one body may act upon another at a distance through a vacuum without the mediation of anything else, by and through which their action and force may be conveyed from one another, is to me so great an absurdity that, I believe, no man who has in philosophic matters a competent faculty of thinking could ever fall into it.”

Newton was careful to say that he didn’t know why gravity works and what causes it, merely that it does work according to the equations. In the second edition of Principia he wrote.

“I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses... It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.”

By the way, this also refutes the idea suggested in a previous chapter that scientists were satisfied at the time that Newton’s laws represented a terminus in scientific understanding.

Anyway, on with Swinburne’s simplicity of theism.

Yet a person with zero powers would not be a person at all. So in postulating a person with infinite power, the theist is postulating a person with the simplest kind of power possible.

By accident, Swinburne lets slip a fundamental weakness of his case, even stated in its own terms. A lack of a person, and therefore no associated powers, is simpler – it is zero in both cases, whereas a single person with infinite powers is a single person, and therefore more complex. But onward…

God’s beliefs have a similar infinite quality. Human persons have some few finite beliefs, some true, some fasle, some justified, some not. In so far as they are true and justified (or at any rate justified in a certain way), beliefs amount to knowledge. It would seem most consonant with his omnipotence that an omnipotent being have beliefs that amount to knowledge. For, without true beliefs about the consequences of your actions, you may fail to realize your intentions.

This isn’t making any kind of argument about simplicity. This is merely taking a premise (that God is omnipotent) and following a line of argument that leads to a conclusion that God is also omniscient. The value of the conclusion is only as good as its premise, and so this line of reasoning doesn’t seem to add anything to his claims of prior probability at all.

For a person to act, he has to have intentions. A person could be omnipotent in the sense that whatever (logically possible) action he formed the intention to do, he would succeed in doing, and also omniscient so that he knew what were all the (logically possible) actions available to an omnipotent being in his situation, and yet be predetermined to form certain intentions. His intentions might be determined by causal factors outside his control, or at any rate, as are those of humans, greatly influenced by them. But, if a person is predetermined (or has an inbuilt probabilistic tendency) to act in certain specific ways, this means that a tendency to act in certain ways is built into him. But a person with an inbuilt detailed specification of how to act is a much more complex person than one whose actions are determined only by his uncaused choice at the moment of choice. Such a being I call a perfectly free being. Theism in postulating that God is perfectly free makes the simplest supposition about his choice of intentions.

This tells us nothing about whether such a being is possible. It seems to me that the greater the capabilities, the greater the complexity needed in order to achieve them, and if there is perfect freedom in terms of intentions, then I suggest that involves quite a lot of capability.

A substance who is essentially omnipotent, omniscient, and perfectly free is necessarily a terminus of complete explanation. For if some state of affairs E is explained as brought about by God in virtue of his powers and beliefs and intentions, to bring about E, how can the action be further explained?

Well, it would help if there were an explanation of how God came to be in the first place. Swinburne argues as follows

God’s being omnipotent, omniscient, and perfectly free is involved in his existing, given that, as we have supposed, these qualities belong to the divine essence. But his existing cannot be due to any contemporaneous factor that makes him exist or allows him to exist. For, if his existence depended on some factor apart from himself, that factor could not depend for its existence on himself (for one cannot have causation in a circle). But if this factor did not depend on God, then God would not have been able to make it exist or not exist, and so would not be omnipotent.

It seems to me that Swinburne has rather painted himself into a corner here. There is no means of explaining the existence of an omnipotent God, since any factor causing God to come into being is by definition not under God’s control, and this would render God not omnipotent. But if he isn’t omnipotent but has circumscribed powers, then the limit of those powers is something which in turn needs to be explained.

Therefore, we simply have to accept the prior probability of a God whose existence (in the form defined by Swinburne) is fundamentally inexplicable without engaging in logical contradictions.

But despite all this, Swinburne grandly concludes.

The intrinsic probability of theism is, relative to other hypotheses about what there is, very high, because of the great simplicity of the hypothesis of theism.

I notice he manages to reach the end of the chapter and conclude that theism is intrinsically more probable than any other hypothesis without considering in detail or even naming any other hypotheses. Moreover he has incorrectly stated the necessary comparison. The correct comparison is the hypothesis of theism against the sum of all hypotheses which do not posit the existence of the theistic God.

Spong: Jesus Beyond Incarnation

In the next two chapters, Spong looks at what can be said of Jesus if he is not the Incarnate Son of God. Spong is aware that there might be no recognisably Christian religion left at the end of the transformation he looks for. But he is certain that if the transformation isn’t undertaken, then eventually there will definitely be no Christian religion left. So in his view the road, however rocky, must be travelled.

Spong goes on a bit more about the discrepancies between the birth stores as provided by Luke and Matthew. They are impossible to reconcile, either with each other or in terms of dates with the other historical evidence in existence. Furthermore, the ancient understanding of reproduction was that the man provided the seed, and the woman the garden in which the new life grew. So it was thought a relatively straightforward matter for a God to plant a divine seed in a woman and have a son of God grow up who was wholly divine. We now know better - the woman provides half the genetic material and contributes equally to the inherited characteristics of the child. So the traditional understanding of the Incarnation is completely inoperative in the face of modern knowledge.

The Ascension fares no better than the Incarnation in terms of modern knowledge. We now know that ancient conceptions of a three-decker universe are far wide of the mark. So the Ascension cannot have been a physical event, since if you simply ascend, you either reach orbit, or the depths of a universe so vast and empty it is hard to comprehend.

The doctrine of atonement is similarly unsupportable, since there never was a first man and woman in a perfect creation who spoiled it all by falling into sin. Creation is as yet unfinished and is continually developing, to ends we do not yet know. If there never was an Original Sin that spoiled the original perfect creation, there cannot be a need for subsequent generations perpetually to atone for it.

Spong claims that many mainstream churches are dying because their congregations find it increasingly difficult to reconcile their modern knowledge of the world with the claims of traditional theistic Christianity, and the members are simply leaving. Some churches try to find other reasons to exist, but most are simply dying of boredom.

The challenge, according to Spong, is to find a new context into which we can put Christ’s life and gain a new understanding of who he was. Looking for this understanding is the task he sets in chapter 8 “Jesus Beyond Incarnation: A Nontheistic Divinity”.

Spong seeks to answer the question which the New Testament suggests Jesus posed “Who do you think I am?”. Peter is said to have answered “You are the Christ, the son of the Living God” (Matt 16:15-16). Spong looks to see if that phrase can be re-interpreted in nontheistic terms.

Not terribly surprisingly, he concludes that this is possible.

When I being to explore the life of this Jesus apart from the theistic framework of the Christian past, I am energized and even enchanted as a whole new vision emerges. What I see is a new portrait of Jesus. He is one who was more deeply and fully alive than anyone else I have ever encountered, whether in my lifetime, in history, or in literature. I see him pointing to something he calls the realm (or kingdom) of God, where new possibilities demand to be considered. I see him portrayed as one who was constantly dismantling the barriers that separate people from one another. I see him inviting his followers to join with him, to walk without fear beyond those security boundaries that always prohibit, block, or deny access to a deeper humanity.

All very well and good. One hesitates to pour cold water on such an uplifting vision, but a bit of caution I think is called for. First, Spong was rigorous in refusing to accept the literal truth of the Gospel accounts when they were in conflict with scientific an historical knowledge. Having done so, it is not possibly suddenly to turn round and accept their truth in support of his alternate conception of Christ. I’m perfectly sure that Spong is being entirely honest and not deliberately setting up a double standard here, yet that is the effect of his approach.

But perhaps that doesn’t matter too much. After all, stories can be told and written in order to communicate moral or inspirational points, and the point is not lost merely because the events related are known to be fictional. The character of Gollum in The Lord of the Rings is a very fine portrait of the depths of evil to which humans are capable of descending, but to accept it as such does not require you to believe that The Lord of the Rings is history, and that an archaeologist will some day stumble on the ruins of Rivendell. So Spong can treat the gospels as the story of a person more fully alive than any other, without having to accept that the details of the story are all historically true.

This seems to be the approach Spong is taking, though I’m not entirely sure. Judge for yourself.

To the extent that Buddha, Moses, Elijah, Isaiah, Krishna, Mohammed, Confucius, Julian of Norwich, Catherine of Genoa, Hildegard of Bingen, Rosa Parks, Florence Nightingale, Mahatma Ghandi, Martin Buber, Thich Nhat Hahn, Dah Hammarskjöld, or any other holy person brings life, love, and being to another, then to that degree that person is to me the word of God incarnate. No fence can be placed round the Being of God. The suggestion that Jesus is of a different kind of substance and therefore different from every other human being in kind instead of in degree will ultimately have to be abandoned.

It has been very interesting to read and blog Spong in parallel with Swinburne. The contrast between them could hardly be greater. Swinburne is certain of his conception of God, and goes forth to argue in favour of it. You can decide whether he is right or wrong, but at least it is clear what he is being right or wrong about.

With Spong, things are much more uncertain. I get the impression that for all his eloquence and his obvious honesty, he has genuine difficulty in finding words to express the concepts he is struggling towards, and is in many ways not even sure of those concepts in his own mind. For that reason, while I disagree with some of his thoughts, I have far more respect for Spong than Swinburne, because Spong is still learning. In his book, Swinburne gives the impression that he stopped learning long ago. Swinburne’s book is a book of justification, Spong’s is a work of exploration. He has painfully decided he cannot stay where he is, but does not know where his journey will end.

Catholic clerical abuse at Ealing Abbey and St. Benedict's School

This tale of clerical abuse is a bit too close to home for comfort.

Father David Pearce of Ealing Abbey, retired headmaster of the junior school at St. Benedict's School, has pleaded guilty to 10 cases of indecent assault and one of sexual assault against boys at the school, on dates ranging from 1972 to January of this year.

My son went to that school.

He's OK. I've checked with him. He was only in the junior school and nothing happened to him. From what I can gather, the reported assaults were against boys in the senior school. He had heard rumours of goings-on, mostly since he had left the school.

Ever since the sex abuse scandals first hit the Catholic Church, I have wondered how widespread it was, and whether anywhere local would be affected. The abuse elsewhere seemed so widespread and systematic, and there seemed to be nothing particularly exceptional about any of the places where it happened, and before it was made public it seemed that little was done by the church to prevent or deal with it.

I have to say that while I am extremely shocked that this has happened so close to me, I cannot say that I am in the least bit surprised.

I am very saddened but even less surprised that there is no mention of Father Pearce on the St Benedict's school web site - no apology, no contact number for concerned parents of present or past pupils, no offers of pastoral care to other possible victims who haven't yet come forward. It is as if Pearce - former headmaster of the junior school - never existed.

Nor is there any mention of him on the Ealing Abbey website, beyond his continued listing as one of the monks "resident elsewhere".

Nor is there any kind of apology or mention of the matter on the website of the Westminster diocese.

This seems to be a pathetically inadequate public response.

It isn't even as if the authorities were unaware of the existence of problems. Back in April 2006, a former pupil won damages against Father Pearce and Ealing Abbey in the High Court.

And yet, according to the BBC report of his arrest, the criminal investigation was into incidents between 2006 and 2007, and according to the Ealing Gazette report the abuse did not finally end until last January when Pearce was arrested.

So, it appears Pearce had contact with children and the opportunity to continue abusing them even after civil damages were awarded against Ealing Abbey for his abuse of children, at least until his arrest.

I don't suppose many of the parishioners at Ealing Abbey are likely to read this blog, but for any who do, I have this plea to make to you.

I know that most of you had no idea this was going on. I know that most of you are in no way responsible for the actions of a few evil individuals. But now that it is known, all the parishioners have a responsibility and a duty to do all you can to ensure that this can never happen again at the Abbey or at any of its schools, and to ensure that everything possible is done to help the victims.

You can demand that the Abbey's records on all matters of complaints or allegations of sexual abuse connected to the Abbey are independently reviewed, to see whether appropriate actions were taken in respect of any and all complaints. Such a review should go back least 40 years. Now, it would clearly be inappropriate for all the Abbey's records to be made public - there are issues of confidentiality with respect to the names of possible victims. But it is perfectly reasonable for all records to be turned over to some independent expert tasked with investigating the matter on behalf of the parishioners.

• An independent external investigation is necessary, because it appears that the Abbey has proved unable or unwilling by itself to guard against this kind of abuse. The report should be as comprehensive as possible subject to maintaining confidentiality with regard to the identities of victims
• The expert should preferably be a non-Catholic, so that there is no reason for people to believe in any complicity by the church to cover up or minimise the extent of any problems.
• The report should state whether there was any lack of co-operation on the part of anybody who in the past or present has acted in an official capacity at the Abbey or any of the schools, and it should name those who failed to co-operate fully and describe the nature of the lack of co-operation.
• The report should should be made public.

As parishioners and as parents and grandparents of present and future pupils at St Benedict's School, you deserve to know the extent of past abuses. Only with this knowledge can you know what measures need to be taken to ensure with the greatest possible certainty that any kind of repetition of this is impossible.

You can demand that provisions are made for counselling and pastoral care to be provided to other victims. If the abuse stretches back to 1972, then it is certain that there are more victims (possibly very many more) than have been mentioned in the criminal and civil cases. Those victims deserve your help and support, whether or not they have yet come forward. The support should probably be provided by people with no official connection to the Abbey, and should include provision for professional counselling of anybody in need of it.

You can demand that a full and unreserved public apology be issued in the name of the Abbey to all victims of Father Pearce. It is incredibly sad that such a public apology has not already been provided unprompted. ut better late than never.

You can demand that the parish and the schools review their child protection policies and ensure that they meet all current legal requirements and conform to all the relevant "best practice" guidelines issued by the relevant expert bodies. You can demand that the policies are independently audited on a regular basis to ensure that that they are kept up-to-date and are consistently adhered to.

You can choose to withhold your planned giving to the Abbey unless and until these actions have been carried out to your satisfaction. You can decide for the time being to divert your charitable giving to secular charities, or you can put your money into a separate bank account to be given to the Abbey only if and when it has demonstrated that it is a fit recipient for your charitable donations, or you can divert your giving to help pay for the cost of the investigation or to the expenses involved in providing the victim support.

The church is not the victim here. The damage to the church has not happened because these matters were made public, the damage has occurred because the events happened in the first place, and has been made far worse because it took so long for it to become public and to be stopped.

Please do not enter into a siege mentality of believing that everybody in the secular world is ganging up against the Catholic Church. That will do a disservice to those who have really suffered in all this. The children at the school, both past and present, are the victims. The victims probably include people you know, and the children of families who are friends of yours. The past abuse cannot be undone. But it is within your power to see to it that something is done to minimise the damage to those who were abused, and to minimise the risk to future children.

Please do what you can for the victims, and to make sure there are no more victims in future.

Swinburne: "Complete" explanations

In chapter 4, Swinburne looks at what makes a Complete Explanation. He starts out by looking at what he regards as possible limits to scientific explanations.

Phenomena of two kinds can be shown not to be explicable scientifically. First there are the phenomena which are too odd to be fitted into the established pattern of scientific explanation, and, secondly, there are phenomena that are too big to be fitted into any pattern of scientific explanation.

This seems to be a variety of the Argument from Personal Incredulity. If Swinburne thinks some phenomenon is too strange or big to have occurred naturally, then God possibly/probably did it. (The phenomena he is thinking of are both too strange and too big to fit into the category of personal explanations in the form of intentional actions by humans.)

The most obvious problem with this approach can be easily shown by a brief look at the history of science, which shows a progressive widening of the scope of things which were previously thought to be the work of God but which have since been shown to be the result of the operation of unchanging natural laws. It seems that our perception of what is too odd to have a natural explanation is constantly changing, a fact which Swinburne seems not to take into account.

Swinburne goes on further about odd phenomena:

To show phenomena too odd to be explicable scientifically, the theist needs to show that there is good evidence for a scientific system h covering a certain range of phenomena, but that it is not a consequence of h (within the general range of h) occur, and that any attempt to amend or expand h that would allow it to predict e would make h so complex that it would be very improbable that it is true.

This is again a gross misuse of the term “improbable”.

Swinburne describes two categories of odd phenomena. One is miracles, and the other is general classes of phenomena for which a scientific explanation is too complex to be plausible.

If a phenomenon can be accurately explained and predicted by means of a theory, I see no reason to be concerned with how complex the equations are. I’m sure I would rapidly get lost in the mathematics of quantum electrodynamics for which Richard Feynmann received his Nobel Prize. Is the fact that the equations for explaining something supposedly very simple (i.e. the behaviour of subatomic particles such as electrons) are very complex a reason for thinking the theory isn’t true? Do we have instead to assume that Feymann’s quantum electrodynamics is wrong (even though its predictions are very accurate) and that it is really God making all those electrons behave in that particular way? Swinburne (at this stage) offers no criteria for deciding whether a scientific explanation for a phenomenon is too complex to be plausible.

Swinburne also makes a description of big phenomena

The other phenomena that cannot be explained scientifically are phenomena that are too big for science, and too big not merely for some particular well-established scientific system, but for any scientific system. … But what, as I shall show more precisely in chapter 7, science cannot explain is why there are any states of affairs at all; it can only explain why, given that there are such states, this state is followed by that state. Nor could it explain, as I shall show more precisely in chapter 8, why the most fundamental natural laws of all hold. Either these are brute facts about the world, or they have an explanation of a different kind.

Quite clearly, we don’t have those scientific explanations yet. But Swinburne’s assertion is that it is fundamentally impossible for science to elucidate these matters at any point in the future.

When making such statements regarding ultimate limits to knowledge (as opposed to the limits of what we have learned so far), it is wise to couch them in something more than a statement to the effect “I don’t see how this could ever be found out”.

Let’s give Swinburne the benefit of the doubt here - all he is so far saying is that he thinks there are ultimate limits - he isn’t (yet) saying where they are or why. We can wait for those later chapters to see him expand on this theme.

Next Swinburne goes on to make several definitions of varieties of complete explanation. I suspect these will get used extensively further on in the book, so we had better be familiar with them.

A full explanation of a phenomenon exists if it includes a cause and a reason, which together necessitate its occurrence. (The cause is the initial condition and the reason is the operation of some law of behaviour.) If a phenomenon has a full explanation, nothing more needs to be described about how the initial condition resulted in the final state.

A partial explanation is where the suggested cause and reason, while necessary to the understanding of the final state, leave unexplained or unstated the operation of some underlying law. (In Dennett’s nomenclature as described previously, the use of the design stance would be a partial explanation of exactly this kind.)

A complete explanation is a full explanation where the details of the causes - the initial conditions, and the manner of operation of the reasons is itself explained.

Quite why this deserves a separate definition is not clear, but there it is. It seems to me that there are varying degrees of partial explanation which are described at varying levels of abstraction, and the varying levels don’t really need separate definitions - you merely need to know what level of abstraction you are working with and therefore what assumptions are being made about the underlying physical laws whose operation has been abstracted. For instance, laws of chemistry assume that the laws of physics are in operation, laws of cell biology in turn assume the operation of the laws of chemistry, and the laws of botany or zoology assume that the laws of cell biology are working. When explaining something, you choose the level of abstraction that is appropriate to the situation. Of course, there is a need to ensure that your abstractions are correct, and that nothing that you postulate within your chemical theories actually violates any known laws of physics.

Then an ultimate explanation is a complete explanation which traces itself back to original causes - ultimate brute facts for which there is no further explanation.

Finally there is an absolute explanation which is an ultimate explanation in which all the factors cited are either self-explanatory or logically necessary.

We don’t yet have ultimate or absolute explanations for the universe, and might never discover them. Nevertheless, Swinburne is confident that it is possible to decide on the basis of balance of probability whether the ultimate explanation for the universe is God. He shies away from claiming that God is an absolute explanation, since he considers it impossible for anything to explain itself.

Swinburne then describes how Newton’s laws of motion were so delightfully simple and so powerful in their explanatory scope that the scientists of the day genuinely believed that science had reached a terminus in Newton’s laws. We aren’t in that position today, but Swinburne suggests that if and when a theory of that explanatory power is devised that explains all the phenomena we know of today, then we will have good reason to believe we are at a terminus. Quite why a mistaken past belief of the existence of a terminus in explanation should be regarded as a model for defining criteria for a future belief that a terminus has been found is left unexplained. It seems to me that something more than simplicity and explanatory power is going to be needed if we are to be sure we haven’t fooled ourselves into thinking that there are no new unexplained phenomena to be discovered.

Although simplicity is regarded by Swinburne as an indicator of “prior probability” (a term I dislike for reasons stated before) he gives no indication as to what level of complexity in his view rules out a natural law as being a plausible explanation. Trying to work out what he means in all this is a bit like trying to wrestle with fog. One always harbours the suspicion that these criteria will get refined at a later stage so that God just so happens to turn out to be really quite probable.

Swinburne now turns again to personal explanations. Time for another quote.

Scientific and personal explanations are on a level—that is, are rivals for the explanation of phenomena—it would seem to follow that a scientific explanation could explain a personal one, and conversely; and that the criteria that it does so are any gain of prior probability and explanatory power that would result from supposing that it does. By a scientific explanation explaining a personal explanation, I do not mean the one being analysed in terms of the other—we saw in Chapter 2 that a personal explanation cannot be explained in terms of a scientific explanation, and it is surely equally plausible to suppose that a scientific explanation cannot be analysed in terms of a personal explanation. What, rather, I do mean by a scientific explanation explaining a personal explanation is the existence and operation of the factors being involved in a personal explanation being explained by the existence of factors involved in a scientific explanation. A scientific explanation might be given of how people come to exist, and to have the intentions, beliefs and basic powers that they have.

Hang on! Back in chapter 2 he was saying that personal explanations aren’t scientifically analysable, and now he is saying that they are. Or perhaps he is saying that they both are and aren’t. If intentions are analysable in the terms he has just described (and which by the way agrees quite nicely with Dennett’s approach), then there is no need to posit the inescapable dualism he brought up in Chapter 2. It seems that this argument is in danger of disappearing up its own fundament.

But let us go on and see what more he has to say on this.

It is the programme of physicalism to effect a reduction of just this kind. The theist who tries to explain why the world is and works as it does is attempting the reverse programme—to give a personal explanation in terms of God, of the existence and operation of the factors involved in scientific explanation.

In what sense would such an explanation be an ultimate or absolute explanation which Swinburne is seeking? By his own definitions, complete explanations work by taking full explanations pitched at a high level of abstraction, and explaining them by means of the operation of physical laws at a lower level of abstraction. By all appearances, explanations expressed in terms of intentions are an extremely high level of abstraction, depending in turn on the laws of biology, of chemistry and physics for progressively more detailed levels of explanation.

So if we are looking for an ultimate explanation expressed in terms of theism, we would need to explain how God’s intentions (unlike human ones) operate at the lowest level of abstraction – below that of physics, instead of at a very high level of abstraction – above that of biology. Let’s see what Swinburne makes of that in future chapters.

Swinburne chapter 3, The Justification of Explanation

In chapter 3, The Justification of Explanation, Swinburne looks at the grounds for deciding whether a particular explanation of some phenomenon is a good one.

Swinburne is more interested in his scientifically unanalysable personal explanations, but starts out with scientific explanations. And he seems to have some very odd ideas about how scientific theories are developed.

He starts out by defining a term he uses a great deal from here on: prior probability. According to Swinburne:

The prior probability of a theory is its probability before we consider the detailed evidence cited in its support. The prior probability of a theory depends on its degree of fit with background knowledge (an a posteriori matter), and on its simplicity.

This is so wrong and backwards that it is hard even to start explaining how terribly bad this line of reasoning really is.

Firstly, the fact is quite simply that scientific theories aren’t devised this way. As a scientist, you don’t start with a theory and then go looking round for detailed evidence which might or might not end up fitting it. You start with the detailed evidence which is so far unexplained by existing theories, and see if you can work out a theory which explains it. Starting with a theory and then looking around for evidence for it is what many religious people imagine scientists do (as I have mentioned before), but I hadn’t expected somebody of Swinburne’s academic achievements to fall into this particular trap.

Next we have this dread word probability again. We aren’t dealing with statistical data, nor are we dealing with known causes. When we develop a new scientific theory, we are trying to elucidate previously unknown causes. The techniques of probability mathematics are entirely inappropriate here. When your causes are unknown, even if you think that you are developing a probabilistic theory, such as used in quantum mechanics, you do not and cannot evaluate the prior probability of a theory in this way.

And even in those cases where you do use probability and statistics a lot, such as in the analysis of clinical trial data to assess the effectiveness of some new drug, you can’t go back into your data and revise your hypothesis so that the data is now being used to answer a different question from the one you were asking before you collected the statistics, so that you get some kind of positive answer. Games like that make the mathematics go all wonky, even when the use of statistical techniques is appropriate.

Lastly, the scientific understanding of simplicity is quite different from Swinburne’s. A scientific theory is regarded as appropriately simple if it includes no more than is necessary to explain the phenomena in question and make predictions concerning the future behaviour of them and possibly also of other phenomena so far unobserved. So Newton’s theory of gravity is appropriately simple because it talks of a gravitational force, and describes its strength. It doesn’t make the claim that the sun exerts its force on the planets by sending out teams of invisible horses to drag the planets along their orbits. Such a claim (whether or not it happened to be true) offers no predictive power and no additional explanatory power relative to the phenomena addressed by the theory.

It is utterly meaningless to say that the theory would have been “simpler” had the gravitational force been inversely proportional to the distance between bodies rather than to the square of the distance. That greater supposed simplicity has no effect on whether the theory has a higher “prior probability” of being right before you look at the detailed evidence, because you already know that the detailed evidence doesn’t fit the simpler theory, and so you know (without any kind of evaluation of probability) that the simpler theory is simply wrong. In any scientific theory, you make our explanation as complex as is necessary to provide a generalisation which allows you to explain existing phenomena and predict future phenomena.

Swinburne then goes on to look at personal explanations and the use of prior probability. Leaving aside his dubious claim that personal explanations cannot be analysed scientifically, he is on somewhat firmer ground here, because there are lots of people in the world, and you can make statistical analyses of the sorts of things they do, and “prior probability” can return to its traditional meaning within the realms of statistical mathematics, particularly of Bayes’ Theorem. In other words, when making theories about humans behave, it is perfectly possible to create those theories in the form of P-inductive arguments.

But this doesn't help much, since Swinburne isn’t much interested (at least not in this book) in the prior probability of events caused by humans. He is interested in the “prior probability” of events of unknown ultimate cause and which he thinks might have been caused by God. At this point he is back into the realms of serious abuse of mathematics and statistics. All the equations he quotes are all perfectly good equations – when used within their appropriate context. As far as I can tell, he hasn’t made any obvious mathematical howlers, though quite frankly I haven’t looked all that hard because it really doesn’t matter whether he has the algebra right or not. The use of Bayes’ equations in this context is totally inappropriate and any conclusions based on them are completely worthless.