Friday, September 22, 2006

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 (http://www.butterfliesandwheels.com/notes.php) 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.

2 comments:

G. Tingey said...

Thank you, for saying..."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)."

I assume that came from reading my repeated "No god is detectable (even if that "god" exists)" on B&W repeatedly!

Seriously though, if this IS the case, then why bother.
If this is not the case, then let's see the evidence.

Anonymous said...

I've just been making much the same point today. Merlijn disagrees with me - but really - it just seems to me far too easy simply to say god can be both transcendent and immanent. It's just some words. Why should anyone believe them? One and the same god walked in the garden with Eve and Adam and created the entire universe? Why should anyone believe that?

OB