Monday, 31 August 2009

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.

Sunday, 30 August 2009

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.

Wednesday, 26 August 2009

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.

Friday, 21 August 2009

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.

Thursday, 20 August 2009

Swinburne Chapter 2: The nature of explanation

In Chapter 2, The Nature of Explanation, Swinburne looks at what constitutes an acceptable explanation for some phenomenon. He looks at three kinds of explanation

  • Scientific explanation
  • Personal explanation
  • Explanation by action of God

He starts by looking at scientific explanations. He starts by taking the most common kind of scientific explanation, which he calls a Hempel deductive-nomological explanation. In this kind of scientific explanation an event or current state of affairs is explained by the operation of natural laws on some set of initial conditions. The question arises as to where the laws have come from, and Swinburne mentions the “regularity view” originating from Hume, where the natural laws are simply the way things behave - in the past, present and future.

Swinburne finds overwhelming objections to the Humean approach.

Whether some regularity constitutes a law depends, on this account, not merely on what has happened but on what will happen in the whole future history of the universe, it follows that whether A causes B now depends on that future history. Yet, how can what is yet to happen (in maybe two billion years’ time) make it the case that A now causes B, and thus explain why B happens? Whether A causes B is surely a matter of what happens now, and whether the world ends in two billion years’ time cannot make any difference to whether A now causes B.

It seems to me that there is a very simple answer to this. By observation, it appears that this is how natural laws actually work - i.e. that they don’t change over time and as far as we can tell they were the same in the far distant past as they are now, and we have no reason to think that they will be different in the far distant future. It seems that Swinburne is confusing causes with effects. If the same law results in A causing B today as would result in C causing D in two billion years doesn’t mean that the A-B event is caused by the C-D event, but rather both have in some part the same cause - i.e. the operation of the same law.

Anyway, Swinburne goes on to describe another form of scientific explanation which he seems to prefer; the substances-powers-and-liabilities (S-P-L) account, where substances have the power to affect other substances around them, and the liability to exercise those powers under certain conditions. In other words, what we think of as being natural laws are merely the properties of substances. In this, he avoids the use of natural laws as universals. To me, it seems a bit of an angels-on-the-head-of-a-pin distinction, in that it doesn’t matter much whether we think of a law (such as gravity) as existing separate from mass, or of being a property of all massive objects. The equations work in just the same way in either case, and the earth is not going to stop moving round the sun just because you have changed the way you think about these things.

Swinburne claims that with the S-P-L account, there is no necessity to assume that because a particular piece of copper has the power to expand and the liability to do so when heated, all other pieces of copper will behave the same way. But the fact is that all pieces of copper do expand in this way, and again, there is no reason to expect that to change in the future.

Then Swinburne goes on to what he calls personal explanations, in other words explanations of events brought about by human actions. He goes at some length to describe intentions, decisions by humans that bring about some action. He uses the S-P-L account to claim that (unlike inanimate objects) humans are able to choose whether they will exercise their powers or not. He uses the term “event” as follows

An event consists in the instantiation of a property in a substance, (or substances, or in events) at a time or the coming into being or ceasing to exist, of a substance. Events include the table being square now, or John being taller than James on 30 March 2001 at 10.00 am, or me coming into existence on 26 December 1934. In order to fulfil the purpose of the definition of ‘event’, we need so to individuate properties that, if you knew what properties had been instantiated in what when, you would know (or could deduce everything that had happened.

Swinburne goes on to claim that personal explanations are unanalysable scientifically. This is a very big and bold claim to make. One would expect that such a radical hypothesis would be backed by some serious and substantial evidence. This is what he provides:

It follows immediately that having an intention cannot be the same event as having some brain event, for you could know that someone was intending to do such-and-such in his action without knowing that he was in a particular brain state, and conversely. These are two different events connected with a subject, even if perhaps of physical necessity they always go together. It is true that other criteria for the two events being the same event might yield a different result—that the two events were the same; but then, to tell the whole history of the world on those other criteria, it would not be enough to know that some event (for example some brain state) had taken place, you would need to know that it had two different somethings, say ‘characteristics’—a brain characteristic, and an intention characteristic—associated with it. Some sort of dualism is unavoidable here, and I suggest that my proposed use of the word ‘event’ provides a neat system of categories by which we can describe the world fully, a system of categories not too distant from ordinary usage.

So, because you don’t know the inner workings of somebody’s brain, you have to conclude that the person’s brain state is not responsible for his intentions? This seems a remarkably thin line of reasoning, especially when such a momentous conclusion “Some sort of dualism is unavoidable here” is based on it.

It appears that it genuinely doesn’t occur to Swinburne that intentions are a property of the detailed workings of the brain, that we experience some of the operations of the brain as intentions, just as we experience other brain activity as emotions. He appears to regard intentions as sui generis, inexplicable in terms of the detailed operations of simpler entities. He’s perfectly aware of the concept in other contexts. When describing his understanding of the S-P-L account he says

The powers and liabilities of large-scale things (e.g. lumps of copper) derive from the powers and liabilities of the small-scale things that compose them (atoms; and ultimately quarks, electrons, etc.).

But it appears that he does not apply the same principle to intentions. He makes no mention of psychology in the whole book - the word simply does not appear in the index. Any physical (and scientific) explanation for how intentions might plausibly come about is not even actively rejected -in this chapter, it is not even mentioned.

Here is Daniel Dennett on the subject of intentions and how we interpret the world around us. He speaks of different stances used to understand aspects of the world.

The most concrete is the physical stance, which is at the level of physics and chemistry. At this level, we are concerned with things such as mass, energy, velocity, and chemical composition. When we predict where a ball is going to land based on its current trajectory, we are taking the physical stance. Another example of this stance comes when we look at a strip made up of two types of metal bonded together and predict how it will bend as the temperature changes, based on the physical properties of the two metals.

Somewhat more abstract is the design stance, which is at the level of biology and engineering. At this level, we are concerned with things such as purpose, function and design. When we predict that a bird will fly when it flaps its wings, on the basis that wings are made for flying, we are taking the design stance. Likewise, we can understand the bimetallic strip as a particular type of thermometer, not concerning ourselves with the details of how this type of thermometer happens to work. We can also recognize the purpose that this thermometer serves inside a thermostat and even generalize to other kinds of thermostats that might use a different sort of thermometer. We can even explain the thermostat in terms of what it's good for, saying that it keeps track of the temperature and turns on the heater whenever it gets below a minimum, turning it off once it reaches a maximum.

Most abstract is the intentional stance, which is at the level of software and minds. At this level, we are concerned with things such as belief, thinking and intent. When we predict that the bird will fly away because it knows the cat is coming, we are taking the intentional stance. Another example would be when we predict that Mary will leave the theater and drive to the restaurant because she sees that the movie is over and is hungry.

Dennett’s point is that you can always use the physical stance because everything obeys the laws of physics. But working things out (particularly complex things like humans) by the physical stance is time consuming, and by the time you have made your prediction the event under consideration is long past, so we use shortcuts.

The design stance is a shortcut, a rule-of-thumb that allows us not to concern ourselves with the physical characteristics of materials and look at their purpose, and predict their behaviour accordingly. It doesn’t matter whether an alarm clock is spring-wound or battery-powered, or by what means it keeps accurate time. Provided that you are familiar with alarm clocks, even if you haven’t seen a particular model before, a cursory examination will allow you to work out how to set the alarm correctly. Similarly, although birds’ wings are not actually designed, but have evolved in such a way as to be useful for flying, we can conclude that any creature with wings of a certain size relative to the creature’s weight is probably able to use those wings to fly.

The intentional stance is an even quicker shortcut, available for when we are dealing with things with mind and intention. We can predict a person’s likely next actions (or those of an animal for that matter) by analysing words (in the case of humans), facial expression, movement etc in order to infer his intentions.

Each of these two shortcuts allows for faster predictions, at the cost of being wrong sometimes. But an occasionally inaccurate prediction that a nearby lion intends to eat you and that it would be an extremely good idea to be somewhere else very quickly seems to me to have great survival value. If you sometimes get out of the way unnecessarily because in fact the lion isn’t interested in you, you have lost nothing except a bit of energy. If the lion catches and eats you while you are still working out its physical characteristics, you have lost everything.

So we have two diametrically opposed accounts here. We have Swinburne’s assertion that intentions are separate from physical events and inexplicable in scientific terms, and Dennett’s approach that phrasing explanations in terms of intentions (using the intentional stance) is a rough-and-ready shortcut to making predictions about the world around us that are accurate enough to have survival value.

The complexity and operation of the human brain is still largely a mystery to us. Neuroscience is still in its infancy and there is a huge storehouse of knowledge yet to be explored. So at the moment, the hypothesis that every intention is associated with a particular kind of brain event is a P-inductive argument, and scientists are looking at the linkages now in order to see what underlying laws might govern the operation of the human brain and mind.

One thing is certain. Brains do exist, and physical or chemical changes in and damage to your brain do affect your mind, including your thoughts and intentions. Brains are of such vast complexity that it will take time to unravel all of the connections involved. But it seems reasonable to have as a working hypothesis that our brains are the source of all our thoughts and intentions, and that our brains obey the laws of physics in their operation. There would only be a need to discard this hypothesis if we come across some other source of thoughts and intentions that is definitely unconnected with events occurring within the brain.

In essence, a large part of science is a process of unravelling the design stance (in biology) and intentional stance (in psychology and neurology) and reducing it to the physical stance and explaining these phenomena in terms of underlying physical laws. But this takes time and we have a long way to go yet.

So it seems to me that Swinburne’s inescapable dualism is not inescapable at all. We may not yet have all the answers, but not yet having the answers doesn’t mean that the answers are forever unobtainable even in principle, and that we need therefore to offer dualism as he only possible way to explain intentions.

I suspect that Swinburne wanted very much to make dualism seem an inevitable part of personal explanations in order to prepare the ground for his third category of explanation: “Explanation by action of God”. If human intentions are inexplicable in scientific terms and require a dualist worldview, then it becomes easy to suggest that some nonhuman disembodied mind also exists, and that this mind has intentions which are similarly inexplicable in scientific terms. Swinburne’s argument is that God is just such a disembodied mind, and that being wholly disembodied, God can directly affect any part of the physical universe with equal ease, and is able to know anything about the physical universe without being dependent on sense impressions impinging on some specific part of the universe.

So, Swinburne’s line of reasoning is that intentional actions (by humans or by God) are of a fundamentally different nature and require a fundamentally different non-scientific mode of explanation from physical events. A whole chapter of explanation seems to boil down to the fact that we don’t have a detailed understanding of the linkage between brain states and intentions, followed by an assertion that no such definite linkage exists, and a resulting conclusion that dualism is inescapable. This seems to me to be God-of-the Gaps reasoning, and as such it is susceptible to embarrassment with every advance made in neuroscience which might offer a causal connection between physical events in our brains and our conscious intentions.

Tuesday, 18 August 2009

Losing and gaining faith

There's an unusually civilised thread over on CiF Belief How did you lose, or find, your faith?

If AB were to refrain from writing and publishing atheist-bashing pieces and do what he claims to want to do, which is foster the kind of respectful atmosphere of this thread, then I would be much more inclined to start commenting there again.

My own situation is quite simple. I was brought up by my churchgoing parents very much in the liberal Anglican tradition. My father eventually became a Lay Reader in the Church of England, entitled to conduct Matins unassisted and to assist with the chalice at communion. And a better, gentler man you couldn't hope to meet. But by the time I was about 12 or so I realised that I had the greatest of problems with accepting all the miracle stuff (and I suspect my parents had similar difficulties, which was why it was never emphasised at home).

I remember being sent off to summer camp one year about this age, and it turned out to be a rather more religious affair than my parents had quite bargained for. At one point in Bible-study classes I asked where Abel's wife had come from, since if Adam and Eve were the first people, and they had no daughter. The answer came back "Good question. I don't know." and that was all the answer I got. When I related the story to my parents they were greatly amused at the question and the lack of answer, and thoroughly approved of me having asked it.

Still, I went through confirmation classes, partly because it didn't occur to me not to, and I didn't want to upset my parents.

Because it was a small village parish in Norfolk, I was the only person undergoing confirmation in the parish at the time, so confirmation classes were one-on-one sessions with the vicar. Apparently my mother asked him at one point how I was doing, and his answer was to the effect that all the right sorts of answers were coming out, but that there was no telling what was going on inside my head. In retrospect, I think that was an extremely perspicacious comment, as in fact I was going though it in exam mode - treating the work between sessions just as any other piece of school homework. Again, it didn't occur to me to do otherwise.

At this time, this kind of gentle liberal Anglicanism was the only experience of religion I had. When I went to university, I quietly abandoned my churchgoing habits, but was persuaded to attend a Christian Union meeting (having previously been asked by a friend to help out in their cricket team against the CU of another college). I have to say I was pretty gobsmacked. It was very evangelical, lots of singing and waving hands in the air, almost as if it was a football match, just a hint of hysteria in the air. There was lots of talk of miracles. One of the students related a story of having found £20 in the gutter just at the time he had had to pay for a replacement rear windscreen on his car, and ascribed the coincidence to God's intervention. I realised that you couldn't justify that connection.

Then I married, and it turned out that my wife's family were Australian Catholics, and my mother-in-law treated her faith in God very much as a superstition in which she genuinely believed. If prayers weren't said at the right sorts of times, all kinds of bad things would happen. This was all a massive turn-off to me, and again, I was undergoing culture shock - it had never occurred to me that there were people who treated their faith this way. In my ignorance, I had thought that almost all Christianity was the kind of gentle liberal Anglicanism I had been brought up in. So all my experiences of religion were in fact gradually persuading me that there wasn't a basis for it all.

On Dawkins' scale, I would have perhaps been a 4 on entering university (i.e. a pretty neutral agnostic) a 5 by the time I left university (an agnostic tending towards atheism). But I wasn't a complete atheist since I acknowledged that there wasn't any way you could disprove God's existence, and I hadn't yet acquired the sophistication of thought on how to deal with unfalsifiable God concepts.

Then in my 30s I joined a private internet forum, which had a bunch of very bright people, and we got discussing just about everything. And when religion came up I found myself arguing against the religious claims most of the time, and increasingly found how threadbare they were. By the time Dawkins published The God Delusion, there wasn't really anything in it that I hadn't already worked out for myself, but it was something of a comfort to see it all written out in black & white in somebody else's words, and to see that others had reached the same conclusions.

About the one thing that TGD did was to make me that much less willing to identify with the liberals against the evangelicals in the Church of England's perpetual tussles between them. Partly as a result of TGD (though I suspect the idea had already been growing in my mind) I concluded that the liberal versions of Christianity were just as irrational as the evangelical versions. Their immediate consequences were less harmful, but in effect they lent cover and respectability to the less reputable forms of religion, and I was not prepared to go along with it.

This weeks Question on CIF includes the following statement:

To gain faith, or lose it, are curiously similar experiences

It is interesting to compare the experiences of those posting with that assertion. It seems to me that gaining faith is very much a sudden and emotional experience. The phrase "born again" captures the essence of it very well. But the various reports of the experiences of losing faith are a very great contrast to that - they are a very gradual process of acknowledgement that the foundations of a person's faith are not fit to bear the structure built on top of them. That is my own experience, and the essence of it seems to have been shared by most others who have described the process of losing faith.

So it appears that gaining faith and losing it are very different kinds of experiences.

I was very struck by the words of Bishop John Shelby Spong when I first came across them.

I do not believe in a deity who can help a nation win a war, intervene to cure a loved one’s sickness, allow a particular athletic team to defeat its opponent, or affect the weather for anyone’s benefit. I do not think it appropriate for me to pretend that those things are possible when everything I know about the natural order of the world I inhabit proclaims that they are not.

That sums me up very well. Spong is still looking for an alternative way of describing his experience of God. I have decided that the God of theism is so thoroughly ingrained as the commonly understood definition of the word that to re-use it with any other meaning is going to cause confusion. So I don't believe in God.

Sunday, 16 August 2009

Swinburne on Inductive Arguments

(I haven't finished with Spong yet, but have decided that I will run the remaining chapters of Spong in parallel with some comments on Richard Swinburne's The Existence of God. Here are some comments on the first chapter of the latter.)

Richard Swinburne is one of Britain’s leading academic theologians. He is a Fellow of the British Academy. From 1985 to 2002 he was Nolloth Professor of the Philosophy of the Christian Religion at the University of Oxford.

Swinburne says in the Preface to the second edition of The Existence of God:

The Existence of God is the central book of all that I have written on the philosophy of religion. It was originally published in 1979. A ‘revised edition’ was published in 1991, but the revision consisted merely in the addition of two appendices; the main text remained intact. The present revision is a far more substantial one.

He goes on to describe the various chapters that have been changed, and the nature of those changes. The book has received good reviews, and it contains material originally published in various academic journals, including Philosophy, Religious Studies, Reason and Religion, American Philosophical Quarterly, Physical Cosmology and Philosophy, Comparative Theology, and Faith and Philosophy. The book is used as a textbook in undergraduate courses on theology and the philosophy of religion.

So this is not some ignorant backwoods preacher who wouldn’t know a philosophical argument if it hit him over the head. This is a serious theologian who sits at or near the top of his academic discipline, and The Existence of God is the book which in his own words is central to his understanding of the philosophy of religion, and which is the result of more than 30 years accumulated thought and wisdom on the subject. If Swinburne had turned up on my blog in response to my invitation to believers to produce an argument in favour of God’s existence, I could hardly have found somebody more qualified to put the case. I’m going to take this book as a kind of response to that invitation.

A bit first on the structure of the book. This is a serious academic work, the language is densely packed - it is not really intended for a popular audience. I don’t mind that - I’m prepared to put in the hard work of reading and understanding it, and explaining to you what it means to the best of my understanding.

If you are looking for simplistic arguments such as arguments from scripture, you will be disappointed. There is little or no biblical quotation, and nothing in the way of argument that “the Bible says X, therefore it must be true”. I’m sure that Swinburne is perfectly well aware that circular arguments (using your assertions as evidence of their own truth) do nothing more than go in circles. Swinburne also makes a deliberate decision to leave aside ontological arguments in this book. All his arguments have as a starting point at least one known and largely undisputed physical fact, such as the existence of the universe.

But it is quite a way into the book before he gets on to any of these arguments. He starts out in the early chapters by describing what he thinks of as being a good structure to an argument. The first six chapters have the following titles:

  1. Inductive Arguments
  2. The Nature of Explanation
  3. The Justification of Explanation
  4. Complete Explanation
  5. The Intrinsic Probability of Theism
  6. The Explanatory Power of Theism: General Considerations

It is only in chapter 7 (after 132 pages of introduction) that he starts on the first of his arguments in favour of God “The Cosmological Argument” using the principles he establishes in the first 6 chapters. He then goes on in subsequent chapters through Teleological Arguments (i.e. arguments from design), Arguments from Consciousness and Morality, The Argument from Providence, The Problem of Evil, Arguments from History and Miracles, and The Argument from Religious Experience. He rounds it all off with a short chapter “The Balance of Probability”.

It would be tempting to skip the first 6 chapters and go straight to the actual arguments. But unless we look first at what Swinburne thinks characterises a good argument, and whether he is right, it is not going to be possible to work out what he is talking about when dealing with the actual arguments.

So it is going to be necessary to look at these early chapters even through they don’t directly address the question of God.

The first chapter is called “Inductive Arguments”. Swinburne starts out by offering three examples of differing kind of arguments. He offers the following as an example of a valid deductive argument, where the premises (provided they are true) make the conclusion certain.

P1: No material bodies travel faster than light.
P2: My car is a material body.
C: My car does not travel faster than light.

The next example he gives is what he calls a P-inductive argument, where the premises, while not making the conclusion certain, render it probably true. How good the P-inductive argument is depends on how probable the premises render the conclusion.

P1: 70% of the inhabitants of the Bogside are Catholic.
P2: Doherty is an inhabitant of the Bogside.
C: Doherty is Catholic.

The third kind of argument Swinburne describes is what he calls a C-inductive argument.

P: All of 100 ravens observed in different parts of the world are black
C: All ravens are black.

That you have seen 100 black ravens does not by itself render the probability very great that all ravens everywhere (past present and future) all have been, are and will be black. But according to Swinburne each additional black raven you come across increases the probability that the conclusion is correct.

Swinburne states

Most of the arguments of scientists from their observational evidence to conclusions about what are the true laws of nature or to the predictions about the results of future experiments or observations are not deductively valid, but are, it would be generally agreed, inductive arguments of one of the above two kinds.

This is true, but before we see how Swinburne proceeds from here, there are a few things that need to be said about that statement.

First, a P-inductive argument can only be built if you have statistical data to work from, in the form of a population of some entities whose characteristics vary, and about which one can draw conclusions based on statistical mathematics. The mathematics of statistics has been well developed over the past 100 years or so, to the extent that a decent understanding of statistics is a necessary part of the syllabus in most scientific subjects at degree level. This is not merely the physical and biological sciences, but also all the engineering disciplines, computer science, and social sciences including sociology, geography and history.

If you want to be a mathematician in this field, it is necessary to know precisely how the mathematics works in order to make new discoveries (otherwise you can end up re-inventing old discoveries). If you merely want to make use of statistical techniques, in order to draw justified conclusions in other fields, then the vital knowledge needed is whether and under what circumstances it is valid to use a particular technique. If you use a statistical technique in circumstances it is not valid for, then your conclusions are worthless - though anybody who doesn’t understand statistics would be unaware of the fact.

Secondly, a C-inductive argument is only valid if you have not come across any contrary observations. In the example given, the observation of a 100 or any larger number of black ravens doesn’t contribute at all to the probability that all ravens are black if you are already aware of the existence of an albino raven. Therefore, conclusions that you draw on the basis of C-inductive arguments are always provisional, until they are overthrown by a contrary observation (i.e. a raven of another colour), or are explained by the discovery of some underlying natural law which explains why all ravens must be black and that it is not possible for ravens to be any other colour. If scientists have a natural law which has been established by means of a C-inductive argument, they always continue to look for that underlying explanation.

Thirdly, to use the term “probability” in the context of C-inductive arguments is misleading, because it suggests you are dealing with statistical mathematics when in fact you aren’t.

This is all very important. Swinburne in the first chapter states that he believes there to be no valid deductive arguments either for or against the existence of God which are based on premises universally accepted to be true. Therefore, the entire book consists of an estimate of the balance of probability of God’s existence, based on the strength of the various P-inductive and C-inductive arguments he works his way through.

The main tool that Swinburne uses is Bayes’ Theorem. In brief summary, Bayes’ Theorem is a mathematical tool that allows you to work backwards when calculating conditional probabilities. Even without Bayes' Theorem, it is easy to work out the probability of some overall outcome consisting of some combination of individual events by multiplying the probabilities of individual events.

Bayes’ Theorem allows you to work in the opposite direction. If that you know that various combinations of events of different probabilities that can lead to a particular outcome, Bayes’ Theorem allows you to calculate the relative probability of the various possible routes to that outcome, given that it has actually happened.

Swinburne doesn’t mention Bayes’ Theorem by name until Chapter 3 and page 66, but he starts using concepts and terms from it right in the first chapter. This is clear from the fact that the index contains the term “confirmation theory” giving page ranges in the first chapter, and then also says under the term “see also Bayes’s Theorem”. Let’s let Swinburne take up the narrative in his own words.

My strategy will be as follows. Let h be our hypothesis - ‘God exists’. Let e1, e2, e3, and so on be the various propositions that people bring forward as evidence for or against his existence, the conjunction of which form e. Let e1 be ‘there is a physical universe’. Then we have the argument from e1 to h - a cosmological argument. In considering this argument I shall assume that we have no other relevant evidence, and so k will be mere tautological evidence [i.e. all other irrelevant knowledge]. Then P(h|e1 & k) represents the probability that God exists given that there is a physical universe - and also given mere tautological evidence, which latter can be ignored. If P(h|e1 & k) > 1/2 then the argument from e1 to h is a good P-inductive argument. If P(h|e1 & k) > P(h|k), then the argument is a good C-inductive argument. But when considering the second argument, from e2 (which will be the conformity of the universe to temporal order), I shall use k to represent the premiss of the first argument e1; and so P(h|e2 & k) will represent the probability that God exists, given that there is a physical universe and that it is subject to temporal order.

You should be able immediately to spot the problem. Since we aren’t dealing with statistical propositions, Swinburne has no statistical data to work from, and so has no numbers to plug into Bayes’ equations.

Moreover, Bayes’ Theorem works only on known causes with known probabilities, (known at least to some degree of precision). Swinburne’s situation is that we don’t know the causes of the universe. Because we don’t know, we have no means of allocating probabilities to this or that hypothesis. All we can do is keep looking for more evidence that enables us to form a hypothesis that goes further than our present knowledge. And when we do so, we still won’t be able to assign a probability to it, since we don’t have a population of universes of differing characteristics from which we can draw statistical conclusions. Any attempt to put a number on it is entirely arbitary, nothing more than saying "I think this is 60% probable because I think that number sounds about right."

This to me seems to be a misuse of statistical techniques so basic that it ought to go into statistics textbooks as a classic example of how not to do it.

I find it hard to account for this remarkable state of apparent ignorance on Swinburne’s part. It seems that he really doesn’t understand the limits of Bayes’ Theorem and the purposes to which it can be put. This would require that in the 17 years in which he was Nolloth Professor at Oxford, surrounded by some of the world’s leading academic experts on almost every topic under the sun, no academic with any knowledge of statistics was invited to read the first chapter of his book (for instance when he was preparing the Revised Edition while at Oxford) and advise whether the use of Bayes’ Theorem in this context was appropriate, and that Swinburne, though surrounded by all these experts, never consulted any of them in order to ensure that he had a correct understanding of Bayes’ Theorem.

Furthermore it would appear that none of the journals which published material subsequently incorporated into this book noticed anything amiss, and likewise none of those who conducted peer review of any of his papers noticed any problem.

If this is the case, then this doesn’t merely reflect extremely poorly on Swinburne himself, but on the whole academic study of theology, and the extent to which it has walled itself off from any other field of knowledge.

There is another possibility: that I’m mistaken in my own understanding of Bayes’ Theorem, and that Swinburne’s use of it is in fact justified. I’ve given my reasons for thinking I’m right. Bayes’ Theorem is well enough documented. You can look it up and judge for yourself.

Thursday, 6 August 2009

Theo Hobson on Faith & Evidence

You might almost think he had been reading my last blog. In Falling into the literalist trap he criticises Bishop Tom Wright for his literalist approach to claiming that the Resurrection is a well-attested historical fact, on grounds not all that dissimilar to those I used. As Theo says:
This is a mug's game: trying to show how strong the historical case is for an empty tomb, for post-death appearances that were not mere hallucinations. In his final paragraph he says: "It is possible to argue historically for the truth of Jesus' resurrection. I and others have done so and the case is remarkably good." My point is that the attempt to argue in this way is bad theology.

Instead we should say to the likes of Rutherford: of course it is not historically likely. We are talking about a miracle, a mystery – something that defies reason. When we assert that this thing happened we are talking in a different way from normal.

That is very much the kind of honest approach I called for in my last blog, and it is to Theo's credit that he is prepared to say it.

Of course, Theo also accurately points out that to accept the Resurrection requires that you abandon reason, at least in the context of this specific belief and those associated with it. You have to accept the truth of something extremely unlikely or even impossible by all scientific knowledge now available to us (we know that the dead don't rise). That is even the case if you refuse to accept the more physical versions of the resurrection story (e.g. Jesus telling Mary Magdalene not to cling to him) and hold more towards the poetic imagery of Paul.

That may be the reason Theo Hobson finds the Resurrection "a difficult thing to talk about, to know what to think about". I can sympathize to a degree, but that sympathy doesn't extend to being willing to abandon reason for this or any other irrational proposition.

Monday, 3 August 2009

Faith and evidence

Both the Tom Wright and Francis Collins stories illustrate an interesting phenomenon. People of faith seem to have remarkably little of it - they are always looking for evidence. You would have thought that they would have the faith the Bible exhorts them to. As Hebrews 11 says:
Now faith is being sure of what we hope for and certain of what we do not see. This is what the ancients were commended for.

By faith we understand that the universe was formed at God's command, so that what is seen was not made out of what was visible. By faith Abel offered God a better sacrifice than Cain did. By faith he was commended as a righteous man, when God spoke well of his offerings. And by faith he still speaks, even though he is dead.
And yet, those supposedly of faith are not prepared simply to say "I believe this, and I don't care what the evidence says." Instead, they see how science, by its careful marshalling of evidence, has gained great prestige in the eyes of the people as a way of explaining the world, and they want some of that prestige to rub off on them. So Creationists try to persuade us of the "evidence" of design, and theologians offer arguments to buttress the assertion of God's existence, and religious scientists talk of scientific discoveries making them feel that God's existence is more plausible.

If they were sufficiently secure in their faith they wouldn't need to bother with this. And if they were sufficiently certain, the example of their faith ought (by their own line of reasoning) to be sufficient to attract others to share in it. But they don't. Curious.

Andrew Brown trolling on his own blog

For somebody who claims to be bored by ya-boo discussions between believers and atheists, Andrew Brown is remarkably keen on stirring them up. His latest effort Sam Harris and Francis Collins is a bash at Sam Harris' NYT article expressing reservations about Collins' nomination as head of the NIH.

Most of what AB says is unworthy of the dignity of any reply, so I'm not going to even bother making any attempt at it. Most of the article is based on quote mining and taking out of context, and as an experienced journalist AB ought to have higher professional standards than that.

But there is one point he makes in the comments which I think is worth highlighting. In response to ChrisWhite3's comment that "surely a scientist who refuses to change his stance in light of fresh evidence is a fairly poor scientist?", AB responds as follows.
Your point would have force if belief in God were a scientific hypothesis. But it isn't. So there's no reason for scientific evidence to affect it.
Let me see if I understand this. Francis Collins is talking as a scientist, explaining how his scientific knowledge has increased his belief in the existence of God, moreover of the existence of a God who intervenes in the universe in miraculous ways, for instance by giving humans souls once their brains had evolved to the point of being able to receive them, or by fine-tuning the universal constants in order to design a universe capable of supporting life. And this not not a matter for scientific enquiry?

Pull the other one! Of course science can investigate such questions using scientific methods.

Now, you can say if you choose "I don't care what the evidence is, I believe that God exists and that Jesus rose from the dead to save me." If Francis Collins had said words to this effect, then I don't think anybody would have thought twice about it - people (even scientists) believe all sorts of irrational things, and by clearly saying he wasn't basing his belief on evidence, it would be equally clear that he wasn't speaking in his professional capacity as a scientist. We're all allowed a private life.

But Collins isn't doing that - he's trying to offer a scientific justification for belief in God. In other words Collins himself is making God a scientific hypothesis. I think that in fact he is correct to do so. Whether God exists, what evidence there is for it, and what sorts of miracles he does if he does exist is a perfectly justifiable line of scientific enquiry.

But Collins seems to be wanting to have his cake & eat it - he is claiming a scientific justification for belief in God, but avoids stating the alternative naturalistic explanations (and they most certainly do exist) for the phenomena he claims to persuade him of the existence of God. In doing so, he is committing the scientific sin of cherry-picking evidence.

That is a serious cause for concern in somebody who is being proposed for a senior scientific management post in charge of billions of dollars of scientific funding. It isn't that he believes in God, but rather that in doing so he is prepared to act unscientifically while talking as a scientist. Big no-no.

Tom Wright and the Resurrection

In an article on CiF, Tom Wright, Bishop of Durham, has a go at Adam Rutherford over the latter's scepticism over the historicity of the resurrection, in The resurrection was as shocking then as it is now.

Tom Wright makes 9 points. Never let it be said that atheists don't seriously consider what is said by Christians in support of their faith.
1. The historical basis of Christianity is vital precisely because Christianity isn't just a moral philosophy or a pathway of spirituality, however much many in late western culture (including in the church) have tried to belittle it by treating it as such. Of course sceptics want Christianity to be "simply a moral philosophy". That's not nearly so challenging as what it actually is.
I'm perfectly prepared to judge Christianity by the claims that Christians make on its behalf. If you want to make a claim concerning the historicity of its founding events, that I'll judge that claim by the same standards of evidence as any other historical proposition. But I suspect you wouldn't like the answer I come up with!
2. The reason many of us refer to the New Testament in dealing with early Christianity is not just that it's "The Bible", but that it's the close-up, often first-hand evidence both for what happened and for what Jesus' first followers made of it all.
It's not first-hand evidence of what happened. None of the Gospels was written within 50 years of the death of Jesus. Most of the earliest books of the New Testament were written by Paul, who never met Jesus and strongly disagreed with those who had met Jesus in respect of what Christian doctrine should be. Paul was converted, made all his journeys, wrote all his epistles, was imprisoned and executed before any of canonical Gospels was ever written.
3. The historical evidence for Jesus himself is extraordinarily good. I have no idea whether the Alpha teachers have gone into the detail of how we know about things in Palestine in the first century, but the evidence dovetails together with remarkable consistency, as I and many others have shown in works of very detailed historical scholarship. From time to time people try to suggest that Jesus of Nazareth never existed, but virtually all historians of whatever background now agree that he did, and most agree that he did and said a significant amount at least of what the four gospels say he did and said.
This is one of those weasel statements that can be interpreted a number of ways. One can argue that the evidence is pretty good that there were itinerant preachers in Palestine at about that time, and that one of them might have even had a name something like Jesus. And on that basis one can claim that the "historical evidence for Jesus himself is extraordinarily good", and extrapolate that to the claim that the evidence is "extraordinarily good" that the Jesus described in the Gospels lived and died and was resurrected as claimed there.

But the historical evidence for that is not nearly so good.
4. Just as Christian faith is far more than a moral philosophy or spiritual pathway (though it includes both as it were en passant), so it is more than a "how to get saved" teaching backed up by a dodgy "miracle". Christian faith declares that, in and through Jesus, the creator of the world launched his plan to rescue the world from the decaying and corrupting force of evil itself. This was (if it was anything at all) an event which brought about a new state of affairs, albeit often in a hidden and paradoxical way (as Jesus kept on saying): the "kingdom of God", that is, the sovereign, rescuing rule of the creator, breaking in to creation. If this stuff didn't happen then Christianity is based on a mistake. You can't rescue it by turning it into a philosophy.
I think the key phrase here is "Christian faith declares". It can declare all it wants to so far as I'm concerned, but unless you are going to produce a bit of evidence to support the truth of the declaration, I'll take it about as seriously as a declaration that the moon is made of green cheese.
5. Of course, this was nonsense in the ancient pagan world, as it is nonsense in the modern pagan world. Nothing new there. The Jewish worldview (in which there is a creator God who has promised to rescue the world, and whose people are somehow a vehicle of this rescue operation) was and is always offensive to pagan worldviews of every sort. The sceptics of today add nothing to the sceptics of the first and second century AD.
Well it depends what you mean by "add nothing". I would suggest that the sceptics of today have a far better understanding of how the world works as compared to those of the first century AD, and that this improved understanding adds something to the the basis for their skepticism.
6. And, of course, we all know that dead people don't rise. Actually, the early Christians knew that too; they didn't suppose that people did rise from the dead from time to time and that Jesus just happened to be one of them. (The other "raisings" in the NT are of course what we would call "near death experiences" – people who are clinically dead and then find themselves called back.) Rather, they claimed that Jesus had as it were gone through death and out the other side into a new form of physicality for which there was no previous example and of which there remains no subsequent example. They knew as well as we do how outrageous that was, but they found themselves compelled to say it. As one of the more sceptical of today's scholars has put it, "It seems that they were doing their best to describe an event for which they didn't have the right language."
Quite frankly, a far more plausible approach to this is that they made the classic is/ought error. When Jesus was crucified, they collectively decided that it couldn't possibly have happened that Jesus was dead, therefore he must have risen. When they had concluded that, it is easy to see how the stories of his rising would have grown in the telling.
7. You can't explain how they came to say what they said unless there were both several "sightings" of and meetings with someone they took to be Jesus, alive again, and an empty tomb where he had been. Without the first, they would have said the grave had been robbed. Without the second, they would have known it was a hallucination (they knew as much about those as we do). But if both occurred, how do we explain them? All other explanations fail to account for the reality of what they said and the change in their lives and their sense of call. (Which can't, by the way, be rubbished by likening it to Jones or Koresh; read Acts and compare and contrast with that sort of stuff.)
You are making the unjustifiable assumption that the events actually happened precisely as described in the Bible. There is every reason to think that this is not so. Therefore your claims that other explanations fail to account for the sense of call of the early Christians isn't true. Many of the followers of Jesus would have had a great emotional investment in believing that nothing bad ultimately could happen to him, and so it is easy to see how miracle stories would grow up around him. For a story to spread it doesn't have to be true, it merely needs to be persuasive.
8. Jesus' resurrection was not, for them, a kind of odd phenomenon which validated a particular atonement theology (though of course all these things are joined up). It isn't an extra thing, bolted on to the outside of a moral philosophy. It is the launching-pad for God's new creation. "Christian spirituality" is learning to live in that new creation. "Christian ethics" is learning to let the power of that new creation shape your life. A Christian political theology is discovering what it means that, through the resurrection, Jesus is the world's true Lord.
Wrong way round. The atonement theology grew up as a result of Jesus death and th stories of his resurrection. And so the atonement theology would be consistent wit the stories that had already developed, wouldn't it? It would have to be, otherwise it wouldn't be persuasive.
9. Ridiculous? Of course. It was in AD 35 and it is today. But actually it makes sense – historically, culturally, philosophically and even dare I say politically. We've tried all sorts of other stuff recently and got fairly stuck, haven't we? But actually that shoulder-shrugging pragmatism, though it might alert people to the fact that normal western scepticism may not have the last word, isn't enough. It is possible to argue historically for the truth of Jesus' resurrection. I and others have done so and the case is remarkably good. But I'm not sure, to be honest, that the writer attending the Alpha course is really interested in the historical argument. If he is, he might look at Surprised by Hope, especially chapters 3 and 4. And if he wants a fuller account, he could tackle The Resurrection of the Son of God.
You seem to want to have your cake & eat it. You want to claim that the historical evidence is good (and therefore good enough to overcome Western shoulder-shrugging pragmatism) and yet it seems to me that you would in such an article would want briefly to put the best of your case, and yet the case is curiously unmade except for ad hominem attacks suggesting that Adam Rutherford isn't interested in the historical argument.