Patrick
Posts: 666
Joined: July 2011
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| Quote (keiths @ Sep. 01 2012,20:52) | | Quote (midwifetoad @ Sep. 01 2012,15:13) | OK. I've been hearing search for a search for years and just tuned it out as bullshit. Can someone play devil's advocate and put the best possible face on this? Explain how it could possibly be relevant?
I'm not joking. |
Okay, here's my best straight-faced attempt at presenting Dembski's argument:
| Quote | 1. A search is a process which attempts to find targets within a larger space of possibilities.
2. A search can be run over and over. Each time it is run, it "lands on" one point in the space of possibilities. If that point is one of the targets, then the search has succeeded. If the landing point is not a target, then the search has failed.
3. A blind search is one in which the "landing point" is chosen purely at random out of the space of possibilities, without favoring any points over others.
4. If the possibility space is huge and the target space is tiny, then a blind search will rarely succeed. The odds of hitting the target are just too low. In other words, the cost of finding the target is high with a blind search.
5. If we use a better search, we improve the odds of hitting the target. In other words, we can reduce the cost of finding the target by employing a better search.
6. However, finding a better search is itself a search ("the search for a search"). It has its own cost, which must be factored in.
7. The total cost of finding a target therefore includes both the cost of the search plus the cost of the "search for a search".
8. According to the Law of Conservation of Information, this total cost is always greater than or equal to the cost of finding the target through a blind search. One way or another, you have to pay the piper in order to find the target.
9. Evolution is a search: it looks for viable organisms (the targets) within the much larger space of possible organisms.
10. Evolution obviously cannot succeed as a blind search, because the target space is too small relative to the possibility space. However, evolution uses the fitness landscape as a source of information to zero in on the target space. (A designer may also inject information at crucial moments.)
11. The fitness landscape doesn't come for free. The total cost of the evolutionary search has to include the cost of the information contained in the fitness landscape.
12. The Law of Conservation of Information tells us that the total cost of the evolutionary search, including the cost of the information contained in the fitness landscape, equals or exceeds the cost of a blind search.
13. Purely material processes don't generate information. They merely rearrange information that was already there. Therefore, no material process can "buy" you a fitness landscape.
14. Thus, the information in the fitness landscape comes from an immaterial intelligence. (And so does any information that is injected along the way.)
15. Without this information, evolution could not succeed.
16. One way or another, then, evolution depends for its success on information generated by an immaterial intelligence.
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It's riddled with holes, but that, to the best of my knowledge, is the argument that Dembski is actually making. |
I would love to see Dembski's response to this. However, like Upright BiPed and his semiotic argument, Dembski avoids clarity in order to insulate himself from potential refutation.
| Quote | 5. If we use a better search, we improve the odds of hitting the target. In other words, we can reduce the cost of finding the target by employing a better search.
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This is where Dembski starts to abuse the NFL theorems. He's slipping in the concepts of explicit targets and costs that he'll misapply to evolutionary biology later.
| Quote | 6. However, finding a better search is itself a search ("the search for a search"). It has its own cost, which must be factored in.
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This is just incorrect (Dembski's argument, not your summary.) Some algorithms work better on some fitness landscapes than do others. It is not surprising that we observe an algorithm (known evolutionary mechanisms) that works well in our fitness landscape (reality) actually working in our fitness landscape. Observing an algorithm that works worse than blind search would be the real surprise.
| Quote | 7. The total cost of finding a target therefore includes both the cost of the search plus the cost of the "search for a search".
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Here's where Dembski goes totally off the rails because of the idea of a cost introduced previously. In the only fitness landscape we observe, only those search functions that work in this landscape will be observed. There is no need to search for a search function.
| Quote | 8. According to the Law of Conservation of Information, this total cost is always greater than or equal to the cost of finding the target through a blind search. One way or another, you have to pay the piper in order to find the target.
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Once again, Dembski fails to show that any search for a search function is necessary or observed.
| Quote | 9. Evolution is a search: it looks for viable organisms (the targets) within the much larger space of possible organisms.
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Just because some aspects of known evolutionary mechanisms can be modeled as a search does not mean that evolution is a search. IDCists often make this error of mistaking the map for the territory.
Evolutionary mechanisms explore the "organism space" immediately adjacent to known good solutions. The much larger space of possible organisms is immaterial.
| Quote | 10. Evolution obviously cannot succeed as a blind search, because the target space is too small relative to the possibility space. However, evolution uses the fitness landscape as a source of information to zero in on the target space. (A designer may also inject information at crucial moments.)
11. The fitness landscape doesn't come for free. The total cost of the evolutionary search has to include the cost of the information contained in the fitness landscape.
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This is where Dembski's entire argument falls apart. The idea that the observed fitness landscape (aka reality) represents a cost presupposes his conclusion that it was somehow selected from a set of alternatives.
| Quote | 12. The Law of Conservation of Information tells us that the total cost of the evolutionary search, including the cost of the information contained in the fitness landscape, equals or exceeds the cost of a blind search.
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Leaving aside the fact that Dembski's "Law" doesn't actually describe any observed regularity, this is just another misuse of the NFL theorems.
The bottom line is that, accepting ad arguendo that evolution can be modeled as a search, we have the single fitness landscape that we observe and we see that an algorithm that works better than blind search on that landscape is reified in chemical processes that result in evolution. That's not exactly surprising.
Dembski might be able to construct a theistic evolution argument from his "search for a search" idea, but it certainly doesn't remotely suggest that known evolutionary mechanisms require intelligent intervention.
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