Sunday, October 4, 2009

Admiration and disagreement...

Mark Chu-Carroll has an excellent blog, Good Math, Bad Math - (I get the feed, which I don't do with all that many blogs). It's reliably intelligent, clear, unfailingly educational and tolerates fools not at all.

But I have to note a point of disagreement with him now.

Mark takes Phil Plait of BadAstronomy to task over what he sees as Plait employing dualism.

Actually, I don't object so much to that, though I think he's making slightly more of it than was necessary; and especially given Phil was in the process of debunking nonsense.

But then he commits what I see as a much graver error than Phil's fairly weak expression of dualism (which he refers to as "sloppy dualism").

In discussing "sloppy dualism" he says:

"But moving from non-determinism to choice is a problem. If you're consistent, and you reject non-physical entities and influences in the world, then you are no exception.

There's no scientific reason to believe that we have free will."

No problem so far - there is really little to no evidence that we have it - and indeed, some experiments do seem to suggest that we in fact may not have it. I know it *feels* like we have it, and we certainly base our society around the assumption that we possess it - but neither of those things means that we do. Our choices can certainly be influenced, that much is clear (which is why so much money is spent on advertising, for example).

He goes further:
"There's non-determinism; but there's not choice."

Okay, fine. We haven't demonstrated that we really choose in the sense of exercising free will -- though I can make some arguments - a series of thought experiments (though you could easily carry them out) - that seem to show we can at least simulate something like that. But that's a post for another time.

He's already begun to push the boundary here - he's gone from saying "we haven't demonstrated choice" to seeming to assert that we can't have choice in a purely naturalistic framework.

[This is not necessarily the case, of course. For example, Penrose suggested that quantum effects come into it. I happen to think Penrose was utterly wrong (not just about microtubules, but the whole quantum-consciousness concept), but the point still stands - there may be ways to have a natural/materialist explanation of these matters, Chu-Carroll's assertions notwithstanding. The onus is on him to make a much better demonstration of impossibility.]

But let's be generous - maybe he's not asserting that - maybe I'm misreading him?

Well, no, he really is. Here's where he goes completely off the rails:

"Choice is the introduction of something, dare I say it, supernatural: some influence that isn't part of the physical interaction, which allows some clusters of matter and energy to decide how they'll collapse a probabilistic waveform into a particular reality."

He has certainly gone beyond anything you can reliably infer fromn Plait's words there. He's also snuck in a whole load of extra stuff with little justification.

But he goes on:

"The funny thing is that at the end of the day, I agree with him. I've mentioned before that I'm a theist. The reason that I'm a theist is because I believe in consciousness."

I have no problem with Chu-Carroll's variety of theism. He's (with the possible tiny exception, which I don't begrudge him) entirely rational - his theism is utterly beside the point here; my problem is with his reasoning.

The progression appears to be (someone please nudge me if you detect a straw man):

- "consciousness is complex" (granted)

- "choice requires consciousness. We don't see a possibility for that to happen in physics" (not granted - I don't see that it's been ruled out even if we can't see a mechanism for it)

- "I therefore have no natural explanation for consciousness" (I don't agree, but let's pretend his argument goes through for now)

- "therefore god"

Wait. WHAT?

This is hoary old argument-from-ignorance - specifically, it's argument from personal incredulity:


The favourite canard of every YEC, every evolution-denier, every muddle-headed biblical literalist...

...from Mark Chu-Carroll? Colour me amazed. Stunned.

Natural explanations are sufficient for everything we can reliably, demonstrably explain at all. But he throws it over rather casually.

The fact is, as Greta Christina points out,

"When you look at the history of what we know about the world, you see a very noticeable pattern. Natural explanations of things have been replacing supernatural explanations of them... as we understood the world better, and learned to observe it more carefully, the religious explanations were replaced by physical cause and effect."

"The number of times that a supernatural or religious explanation of a phenomenon has been replaced by a natural explanation? Thousands upon thousands upon thousands."

"The number of times that a natural explanation of a phenomenon has been replaced by a supernatural or religious one? The number of times humankind has said, "We used to think (X) was caused by physical cause and effect, but now we understand that it's actually caused by God, or spirits, or demons, or the soul"?

Zero Exactly zero."

I commented on his blog (from which I have taken the liberty of extracting part).
The below is simply suggesting a possibility for what we perceive as consciousness - because I am not convinced we have really established consciousness is *real*, let alone that we can't ever explain it naturally:

- Let's take as given (I hope) that the ability to infer intent in the action of other animals has useful survival benefits (as in "that tiger is heading toward the river - it's probably looking for a meal" vs "that tiger's just gone toward its cave after a feed - it's probably looking to have a sleep"), whether the animal in question actually possesses consciousness or even actual intent. Such an ability becomes even more critical in an intelligent social species, like say, wolves or baboons, or even more so in bonobos, chimps, or ourselves, of course.

- Given that inferring intent is potentially useful for survival, demonstrate that what you call consciousness is not something as simple as say, our intention-inferring brain's attempt to rationalize what it observes itself doing.

If it's potentially something reasonably trivial (almost a side effect, perhaps), why invoke something complex without a reason to do so?

- -

Make no mistake, "god" is the most complex possible explanation. Or rather, it's the ultimate non-explanation, because we are never presented with a set of observations with which it's inconsistent. Because it can be plunked down to "explain" any observation, it's completely useless. It's the end of inquiry. It must therefore be the absolute last resort as an explanation, because its the worst possible explanation. And we're nowhere near a last resort.

So the point I was making up there is, before we start saying "consciousness is tricky, therefore god", we need first to demonstrate that there's some "there" there - that consciousness is something "real", something big - not something relatively simple, like a side effect of other brain processes - that we need a complex explanation for.

And then we need to demonstrate that natural explanations are utterly ruled out - and because we have yet to find a single case where we demonstrably can't have a natural explanation, or require a supernatural one, it had better be a very good demonstration.

Mark Chu-Carroll hasn't even come close to making his case.

[As noted before - I can post, but I can't read my blog at the moment. So I can't really see how this looks, except for a rough preview. Apologies if there are errors; as a result I will probably make a lot of tiny edits without specifically marking them as edits, as I notice them from the preview. Please excuse that.]

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