Friday, September 22, 2006

Religious experiences

According to the argument from religious experience, we are supposed to accept religious experiences as evidence for the supernatural, in the absence of positive reasons for thinking that experiencers are deluded. However, this argument is unconvincing, for the following reasons:

Firstly, in the cases of people who claim to have communicated with God, further scrutiny never uncovers any convincing evidence. None of these experiences has ever been independently proved beyond any reasonable doubt to be true – they can always be explained by more mundane, non-supernatural means.

Secondly, religious experience is present in many different religions, and produces largely contradictory and inconsistent claims. As an extreme example, the Yorkshire Ripper claimed that God told him to murder prostitutes. If we are to allow claims of personal religious experience, how are we to determine the false from the supposedly true?

Thirdly, religious experiences typically generate claims that cannot be corroborated by independent evidence (e.g., metaphysical claims, clichés, banalities etc.).

Finally, no new and important scientific, mathematical, or medical knowledge is ever revealed. If an experiencer was ever told something of this nature that is clearly beyond our current knowledge, then this might suggest a phenomenon that needs explaining. Alas, this does not happen.

And, how would we investigate any such supposed claims? Well, for a start, we need to look for reliable, independent evidence that there is indeed some unexplained phenomenon going on here. That’s even before we address the question of whether this phenomenon is in any way supernatural in origin. So far, none of the supposed experiences has even passed the first test.

Theists often cry foul at this point. This type of experience is not amenable to scientific investigation, they say. In their minds, the world in split into those things that can be investigated scientifically, and those that cannot. Religious experiences definitely fit into the latter category, they think. However, under these rules, anybody would be entitled to claim anything that they want, so long as they then rule it off limits to scientific enquiry. I might say that I can communicate telepathically with rocks, or that I can make myself invisible (of course, only when nobody is present, and there are no cameras recording me), or that I can travel through higher dimensions. Obviously, none of these supernatural phenomena is amenable to scientific enquiry, so you’ll just have to take my word for it! This way of trying to fathom the universe is a non-starter.

But even theists don’t apply their logic universally. In general (in the western world), when they are ill they don’t call for an exorcist to expel their demons (even though demons could theoretically be the cause of illness, if we were ignore all of the scientific explanations and evidence); when their car breaks down, they don’t call for a witch doctor to utter some incantation over it (even though, again, this could be the best choice of action if we ignore all of the evidence and rational explanations). Why is this? One could say that it is hypocrisy. But, I think that it goes deeper than this. I think that they know, deep-down, that the world doesn’t work that way, and that the scientific and evidentially-based approach is best choice. They just ask for special pleading in the case of the god of their chosen superstition.

Hume's dictum is apposite here:

"When anyone tells me, that he saw a dead man restored to life, I immediately consider with myself, whether it be more probable, that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous, than the event which he relates; then, and not till then, can he pretend to command my belief or opinion."

In other words, when someone claims the miraculous, is it more likely that they are right or, rather, that they are mistaken or lying?

And, on the subject of evidence, some may hold that this is just question-begging and ultimately illusory. However, how many of them would have the courage of their convictions and call for a complete overhaul of the legal system, to create one in which no evidence is ever examined? How would crimes be tried? That’s a good question. Maybe guilt would be determined by the roll of a die, or by the judge communing privately with god. Then again, maybe not!

The mistake here is to demand absolute certainty in our beliefs. In the real world, this can never be achieved, even in principle. However, predictions made by our beliefs can be more or less in agreement with the evidence; beliefs can be more or less powerful in their explanatory power; and they can be more or less parsimonious. Our understanding of the universe as expressed by our scientific theories is always going to be provisional in nature, and is always subject to further revision. However, to just throw our hands up in the air in resignation at this realisation is futile. Application of reason and the scientific method is still our best hope of making progress in this endeavour. Our attempts to fathom the universe are definitely still a ‘work in progress’, but there is no value in allowing supernatural explanations to fill the gaps in our knowledge, as this has always proved to be premature so far.

Anthropic coincidences

Something that is sometimes mentioned as support for the belief in a god is the so-called anthropic coincidences. Otherwise known as the cosmological fine-tuning argument, this states that even if the origin of all life on Earth can be explained in terms of impersonal natural processes, the mere fact that the universe allows life to exist in the first place is evidence of intelligent design. For instance, for life as we know it to evolve, there must be an unlikely combination of just the right initial conditions and just the right values of a wide variety of physical constants. If any one of the values of several dozen physical constants weren’t "set" to a value extremely close to the actual value we find, then life would not be possible in our universe. The unlikelihood of the universe forming with just the right conditions to allow life by chance is presented as evidence that those conditions were actually set by an intelligent being in order to produce life.

There are a number of issues with this argument. Firstly, it is not at all evident that these constants are so fine-tuned at all. Stephen Hawking says, "The present state of the universe could have arisen from quite a large number of different initial configurations ... so the initial state of the part of the universe that we inhabit did not have to be chosen with great care". We don’t know at present whether all of these fundamental constants are independent of each other. Perhaps it will transpire that there is actually really only one fundamental constant which, once set, determines the values of all of the others. Further, we don’t know what possible ranges of values these constants can take. It may be that the set of possible values is actually very small – making our type of universe not at all unlikely.

Secondly, various multiverse theories that have been proposed by cosmologists that get around the fine-tuning issue completely. According to the 'chaotic inflation' theories of André Linde and others, the expanding cloud of billions of galaxies that we call the big bang may be just one fragment of a much larger universe in which big bangs go off all the time, each one with different values for the fundamental constants. In such a picture, in which the universe contains many parts with different values for what we call the constants of nature, there would be no difficulty in understanding why these constants in our universe take values favourable to intelligent life. There would be a vast number of big bangs in which the constants of nature take values unfavourable for life, and many fewer where life is possible. You don't have to invoke a benevolent designer to explain why we are in one of the parts of the universe where life is possible: in all the other parts of the universe there is no one to raise the question.

An interesting point here is that, as mentioned by Victor Stenger, one needs to introduce additional assumptions in order to prefer a single universe over a multiverse

But, apart from this, perhaps proponents of the fine-tuning argument are guilty of committing the lottery fallacy. If one plays the lottery in the UK, then there is an approximately 1 in 14,000,000 chance of any particular set of six numbers being drawn. So, each time the lottery is run, an event with a one in 14,000,000 probability is going to occur. However, when someone wins the lottery can we therefore infer that the unlikelihood of the event suggests that the lottery is rigged? The answer, of course, is no. Although each particular set of numbers has a 1 in 14,000,000 chance of coming up, there is a 100% chance that one set or other of 6 numbers will be drawn.

Likewise with the anthropic coincidences. Although the chance of the particular set of fundamental constants found in our universe may be infinitesimally small (or, then again, maybe not), some set of fundamental constants may have been inevitable. So, perhaps the fact that there is a particular set of fundamental constants in our universe needs no explaining at all. If the constants were different, then an entirely different type of life might have been pondering the same question.

Of course, the fine-tuning proponent might argue that the true situation is more analogous to buying one lottery ticket, and winning first time – an extremely unlikely event. However, this implies that a universe with us in it is the ‘winning ticket’. Are we really so anthropocentric as to think that our universe is somehow ‘special’, just because it led to us? Actually, I think it would even be difficult to justify the belief that a universe with any type of life is somehow more special than one without. That line of reasoning seems to beg the question. If you specify life as being special – and particularly human life as such – then our universe will necessarily appear to be special. If I roll a die and get a 6, am I then entitled to say, post fact, that a 6 is ‘special’. This type of backwards reasoning is not allowed.

However, even if we assume that a life-producing universe is somehow more special, then we still don’t know how in how many ways a life-producing universe could have emerged from the Big Bang. Perhaps it is not unlikely at all. And, if we look at the subset of all life-producing universes, are we justified in thinking that this particular one is a best case? Our universe is almost entirely lethal to life. By far, most of existence is a radiation-filled vacuum. Life is clearly an extremely rare and unusual product of the universe. We also know it took the universe billions of years to produce any life at all, and then only an extremely simple single-celled life form. Then it took billions more years of a long, meandering and often catastrophically failing process of evolutionary trial-and-error to produce human beings.

So, to conclude, I think that the fine-tuning argument is not at all as persuasive as some believe.

Transcendental god, falsifiability, and Ockham’s razor

I would like to address several points raised recently on the Butterflies and Wheels Notes and Comments section ( with regard to the existence of a transcendental god. I won’t cover each point individually, but will make some general comments.

Here is an example of the type of comment that I am replying to -

"And that's why demands for empirical evidence of its existence are question-begging: by definition, transcendent categories such as God cannot be part of the scientific model of the world."

As far as I can see, one of the issues here is parsimony of explanation or, if you like, Ockham’s razor. Another is falsifiability. It is certainly possible define logically a god who created the universe and who has the following characteristics:

- Transcendental
- Eternal
- Immaterial
- Intangible
- Undetectable by any scientific means, ever (even in principle)
- Not verifiable or falsifiable (even in principle) as the hypothesis makes no predictions about what one would expect to see if it were true, and no predictions about what one would not expect to see if it were true (other than predictions that would equally made by an infinity of other competing hypotheses).
- Etc.

However, I think that one really has to ask at this juncture whether constructing such a hypothesis is anything other than just a meaningless logical exercise? Is it in any way useful in trying to fathom the world around us if one’s working hypothesis is unfalsifiable? (Of course, the god definition given above is not the one generally used by Christians. Their god has other characteristics, and these do make predictions about the world, which are testable) If your one brute fact is that God exists, then it is always possible to interpret everything we see around us in a way that fits with this fact. For such people, it is likely that nothing will ever convince them that they are wrong. However, if one is starting from an impartial position, is it helpful to take the above definition of a universe-creating god as our working hypothesis of the world?

A few analogies might illustrate the point that I am trying to draw out here. For example, it is theoretically possible that I exist only as a brain in a vat, and that all of my physical experiences are illusory - being artificially generated. It would be possible to define this hypothesis in such a way that it is logically watertight, and that it could never, even in principle, be tested, verified, or falsified in any way. Nevertheless, would it be reasonable or fruitful to make this one’s working hypothesis? Or, would it instead be just perverse and futile?

Or, consider the following. Perhaps the whole universe, with me in it, came into existence 5 seconds ago, with my and everyone else’s memories already present. It would be possible to make this hypothesis logically unassailable, and define it in such a way that it could never be verified or falsified, even in principle. Again, would it be reasonable or fruitful to make this one’s working hypothesis? Or, would it instead be just perverse and futile?

In fact, how would we in practice discriminate between the likelihood of either of these two hypotheses? If they are both equally logically consistent, and neither can ever be tested in any way in order to verify or falsify them, then how would we decide which hypothesis to favour? Further, an infinite number of such competing hypotheses could theoretically be concocted. Each would be logically incontrovertible, and none could ever be verified or falsified in any way. So, which one, if any, is correct? The effective odds of any one of them being correct (without any means of testing them) are infinity to one against! If one’s hypotheses are unfalsifiable, then these are the types of problems that need to be solved.

Now, on the subject of parsimony, how about this one (courtesy of Julian Baggini)? Imagine that you are a police officer called to investigate the sound of shooting. You arrive at the house in question, and find a bullet-shaped hole in one of the windows. You enter the house, and look at the wall opposite the window in question. There you find a single bullet embedded in the wall. Now, without any further information, which of the following hypotheses is more reasonable?

1. A single bullet was fired, and this bullet is the one embedded in the wall.
2. A hundred bullets were fired through the same hole. The gunman then broke into the house, leaving no trace whatsoever, and removed all of the bullets save one.

I think most people would elect for hypothesis 1. But, why is that so? The second hypothesis is theoretically possible, so why not judge either hypothesis equally likely? How about if I introduce a third hypothesis that is a variation on the second hypothesis - such that 99 bullets were fired instead of 100? Why stop there? How about hypotheses where 101, 102, 103,… bullets were fired. I could go on indefinitely. Do you see the problem? I have framed the hypotheses in such a way that there is no way to discriminate between them. In such a case, it seems reasonable to go with the most parsimonious theory – the one that introduces the fewest ad-hoc assumptions.

Another example (this one courtesy of Stephen Law). If I look out of my window and see the compost heap at the bottom of the garden, is it more reasonable to think –

1) There is just a compost heap there.
2) In addition to the compost heap, there is also a family of invisible, intangible, immaterial fairies?

The second hypothesis is a logical possibility, so why not make it my working hypothesis, or at least keep an open mind on the subject? Again, Ockham’s razor dictates that in such cases, and with no other information to hand, one should provisionally accept the more parsimonious hypothesis i.e. that there is just the compost heap. Similarly, when we examine the world around us and find that it seems to operate by purely naturalistic processes, do we propose that there exists:

1) Only a naturalistic universe. Or,
2) A naturalistic universe, together with the addition of some unseen, immaterial, transcendent supernatural entity?

In the absence of any other information, I would say that the first option is the more reasonable one.

These analogies illustrate the type of problems that believers in a god face. Either they define their hypothesis in such a way that it can be falsified – and take their chances – or they define it in such a way that it is unfalsifiable. In the former case – such as with the Christian god’s characteristics of omnipotence, omniscience and omnibenevolence, amongst others – predictions are implied about the way that the world would be expected to operate if such a god exists. These predictions can be compared to reality, and are found to be severely wanting – e.g. the notorious problems of suffering and divine hiddenness.

This latter option allows theists to hold onto their beliefs, satisfied in the knowledge that scientists and secular philosophers will never be able to prove them wrong. However, it is really just a bogus victory, as their definition of god is so tenuous and vacuous that it serves no purpose whatsoever. An infinite number of competing hypotheses could be similarly defined, with no way to ever discriminate between them. So, every sentient adult on Earth could theoretically define their own similarly unfalsifiable god hypothesis, and subscribe to that. This way forward seems to me to be futile in the extreme. If our goal is to fathom the universe, rather than engage in logical exercises or to delude oneself in order to preserve one's 'faith', then in my opinion the naturalistic approach is the best bet currently on offer. Saying that an immaterial, transcendent god did it is in no way preferable to just admitting that we don't know the answer yet, but that we are working on it.