Monday, October 06, 2014

Plantinga Reviews Dennett

Isn't that what we're all waiting for? Well, he hasn't reviewed the new one yet, but here is a Plantinga "golden oldie" while you wait.

Here's the interesting part of the paper, concerning Dennett's rebuttal to the fine tuning argument.

Dennett's rejoinder to the argument is that possibly, "there has been an evolution of worlds (in the sense of whole universes) and the world we find ourselves in is simply one among countless others that have existed throughout all eternity." And given infinitely many universes, Dennett thinks, all the possible distributions of values over the cosmological constants would have been tried out; [ 7 ] as it happens, we find ourselves in one of those universes where the constants are such as to allow for the development of intelligent life (where else?).


Well, perhaps all this is logically possible (and then again perhaps not). As a response to a probabilistic argument, however, it's pretty anemic. How would this kind of reply play in Tombstone, or Dodge City? "Waal, shore, Tex, I know it's a leetle mite suspicious that every time I deal I git four aces and a wild card, but have you considered the following? Possibly there is an infinite succession of universes, so that for any possible distribution of possible poker hands, there is a universe in which that possibility is realized; we just happen to find ourselves in one where someone like me always deals himself only aces and wild cards without ever cheating. So put up that shootin' arn and set down 'n shet yore yap, ya dumb galoot." Dennett's reply shows at most ('at most', because that story about infinitely many universes is doubtfully coherent) what was never in question: that the premises of this argument from apparent design do not entail its conclusion. But of course that was conceded from the beginning: it is presented as a probabilistic argument, not one that is deductive valid. Furthermore, since an argument can be good even if it is not deductively valid, you can't refute it just by pointing out that it isn't deductively valid. You might as well reject the argument for evolution by pointing out that the evidence for evolution doesn't entail that it ever took place, but only makes that fact likely. You might as well reject the evidence for the earth's being round by pointing out that there are possible worlds in which we have all the evidence we do have for the earth's being round, but in fact the earth is flat. Whatever the worth of this argument from design, Dennett really fails to address it.

7 comments:

B. Prokop said...

Ha, ha, ha, ha, ha!

Nothing to do with this topic, but about a week ago I did something I almost never do, which is post a comment over at Loftus's website. I checked back once a day to see whether anyone had responded to it, and this morning I discover that John has deleted me!

Seems he can dish it out, but he can't take it!

finney said...

Did you see The New Republic's article on Dawkins? It reference's Arthur Balfour's AFR, and Plantinga's. http://www.newrepublic.com/article/119596/appetite-wonder-review-closed-mind-richard-dawkins

Saints and Sceptics said...

What's Dennett's new book?

Victor Reppert said...

This was actually redated from years ago, so it's Breaking the Spell.

Crude said...

Seems he can dish it out, but he can't take it!

No need to exaggerate, Bob.

John can barely dish it out.

Aragorn said...

"Waal, shore, Tex, I know it's a leetle mite suspicious that every time I deal I git four aces and a wild card, but have you considered the following? Possibly there is an infinite succession of universes, so that for any possible distribution of possible poker hands, there is a universe in which that possibility is realized; we just happen to find ourselves in one where someone like me always deals himself only aces and wild cards without ever cheating. So put up that shootin' arn and set down 'n shet yore yap, ya dumb galoot."

The problem I see with the analogy used in the OP is that we know the probability space of poker hands so that getting four aces and a wild card all the time will be surprising no matter which universe is actual. Observing life among the different universes that are actual will have to be constrained by the existence of life itself in that non-observation of life will be out-selected.

A more apt analogy will be a poker game where numerous iterations of hands are quickly dealt and only those showing four aces and a wild card can be shown to the dealer because of a filter. Surely, getting four aces and a wild card in that situation will not tell us whether the deck is stacked. It's only the viewing that's stacked via the filter (life observing life).

Anonymous said...

There's a far more compelling argument against fine tuning. The universe is expanding, at an accelerating rate. Scientists cannot explain this; the best they can do is postulate "dark energy". But it seems to me the explanation is obvious.

Presumably, space is not continuous below the Planck scale. Also, presumably, the Planck units remain constant as the universe expands. This means that space is a countable set of points, with new points continually appearing.

If each point of space contains its own instance of the laws of physics, then the existence of space as an effective continuum depends on the compatibility of those instances. Points with laws that don't fit in will fade away. Thus the overall laws would have evolved so as to maximize the stability of the universe.

Not only does get rid of the Multiverse assumption, but Inflation as well. Near the beginning of time, a partially formed set of laws of physics would have allowed unruly behavior, such as energy traveling at unlimited speeds. Hence no need for a hypothetical process to have spread it around.