Let us continue with our discussion of Winston Ewert’s defense of the concept of “specified complexity.”
In Part One we saw that Ewert’s defense was actually rather tepid. He mostly gave away the game by writing:
It is true that specified complexity does not in any way help establish that the probability of complex life is low under natural selection. You must have another way of showing that, for example Michael Behe’s irreducible complexity, Doug Axe’s work on proteins, or Stephen Meyer’s work on the Cambrian explosion.
However, all these methods only seek to show that various biological systems are improbable under Darwinian evolution. That is a logical claim distinct from arguing that Darwinian evolution is false. Specified complexity exists to bridge this gap, arguing that we are justified in inferring the falsity of Darwinian evolution on the basis of the low probabilities established by these other arguments.
As we saw last time, this is really just a concession that assertions of specified complexity add nothing to the argument for ID. Such assertions are always parasitic on other ID arguments, and it is those other arguments that are doing all the work.
We also saw that Ewert kept digging by writing this:
Some critics of intelligent design regard this as an obvious point. If complex life were prohibitively improbable under Darwinian evolution (an idea these critics certainly reject), Darwinian evolution would clearly be false. They find it difficult to believe that specified complexity was developed to defend such an obvious point. However, other critics insist that low probabilities of complex life would not provide evidence that we should reject Darwinian evolution.
That sure looks like an admission that “specified complexity” serves only to establish an obvious point. Considering that ID proponents are sometimes fond of referring to William Dembski as the “Isaac Newton of Information Theory,” that’s a pretty damning admission.
But who are these critics who need to have specified complexity explained to them? Well, it turns out that I am one of them. Ewert writes:
In “Can Probability Theory Be Used to Refute Evolution,” Jason Rosenhouse writes:
For suppose that somehow we did manage to carry out such a calculation and suppose we found that it really is terribly improbable than our eye evolved by natural means. What would we learn from such a result?
Almost nothing. Improbable things happen all the time, you see, and the fact that something is improbable does not mean that it cannot happen.
This comes after a quote from philosopher Ingo Brigandt expressing a similar thought, and just before another similar quote from mathematician John Allen Paulos. Ewert then closes with this:
All of these critics argue that we cannot draw conclusions about Darwinian evolution from small probabilities. To be fair, many critics would not agree with these simplistic criticisms of probability arguments. They would in fact argue that evolution makes complex biological systems highly probable. It is unfortunate that these writers feel the need to disparage specified complexity, which exists to defend against an argument they would not make.
Winston Ewert was a student of William Dembski. When it comes to the art of misquotation, it seems he has truly learned at the feet of the master.
Let me begin my reply by noting that Ewert decided for some reason to change the title of my essay. The actual title was, “Can Probability Theory Be Used to Refute Evolution? (Part One).” This is significant, since it was Part Two, not Part One, that discusses the notion of specified complexity.
Part One, by contrast, had nothing to do with specified complexity. I don’t even mention it, much less disparage it. The essay wasn’t even about intelligent design. I don’t mention intelligent design at all until the very end, and I only mention it there to set up Part Two. Part One was specifically about creationist arguments, and since the ID folks are always keen to assert that they are not creationists I am surprised Ewert would make this particular error.
In the essay Ewert links to, I am discussing the especially naïve uses of probability used by creationists. Most of the essay explains why their probability calculations, which entirely ignore the role of natural selection in the evolutionary process, are simply invalid. I also explain why it is impossible to carry out meaningful calculations of the sort they require.
The part Ewert quotes is from near the end of the essay, where I note that even if by some miracle the calculation were valid, it would still tell us next to nothing since improbable events happen all the time. My very next paragraph begins with:
But perhaps the situation is not as simple as I am suggesting.
It builds up to this climax:
This suggests that, while improbability by itself does not suggest anything extraordinary, the combination of improbability with a recognizable pattern does require a special explanation. Could we use this strategy to revive our probabilistic critique of evolution?
Many proponents of Intelligent Design believe that we can. In the second part of this essay, I will show why they are wrong. We will also consider some ways in which evolutionary biologists make legitimate use of probability theory in their work.
And this brings us to the best part. I am surprised that Ewert would think that the statement he quoted makes me look bad. I suspect that Ewert, like most other ID proponents, actually agrees entirely with what I am saying there.
The whole point of talking about specified complexity was that complexity by itself is not enough to indicate design. William Dembski writes, in No Free Lunch, “Even so, complexity (or improbability) is not enough to eliminate chance and establish design (9),” and later, “One concern is that the filter assigns merely improbable events to design. But this is clearly not the case since, in addition to complexity or improbability, the filter needs to assess specification before attributing design (12).” But this is just precisely the point I was making in the statement Ewert quotes.
Of course low probability by itself does not rule out chance. This is obvious and entirely non-controversial even for ID folks. No one thinks that discovering after the fact that the human eye was improbable shows that Darwinian evolution is false, or even challenges the theory in any way.
So why is Ewert pretending not to understand that?
from ScienceBlogs http://ift.tt/1Ttip27
Let us continue with our discussion of Winston Ewert’s defense of the concept of “specified complexity.”
In Part One we saw that Ewert’s defense was actually rather tepid. He mostly gave away the game by writing:
It is true that specified complexity does not in any way help establish that the probability of complex life is low under natural selection. You must have another way of showing that, for example Michael Behe’s irreducible complexity, Doug Axe’s work on proteins, or Stephen Meyer’s work on the Cambrian explosion.
However, all these methods only seek to show that various biological systems are improbable under Darwinian evolution. That is a logical claim distinct from arguing that Darwinian evolution is false. Specified complexity exists to bridge this gap, arguing that we are justified in inferring the falsity of Darwinian evolution on the basis of the low probabilities established by these other arguments.
As we saw last time, this is really just a concession that assertions of specified complexity add nothing to the argument for ID. Such assertions are always parasitic on other ID arguments, and it is those other arguments that are doing all the work.
We also saw that Ewert kept digging by writing this:
Some critics of intelligent design regard this as an obvious point. If complex life were prohibitively improbable under Darwinian evolution (an idea these critics certainly reject), Darwinian evolution would clearly be false. They find it difficult to believe that specified complexity was developed to defend such an obvious point. However, other critics insist that low probabilities of complex life would not provide evidence that we should reject Darwinian evolution.
That sure looks like an admission that “specified complexity” serves only to establish an obvious point. Considering that ID proponents are sometimes fond of referring to William Dembski as the “Isaac Newton of Information Theory,” that’s a pretty damning admission.
But who are these critics who need to have specified complexity explained to them? Well, it turns out that I am one of them. Ewert writes:
In “Can Probability Theory Be Used to Refute Evolution,” Jason Rosenhouse writes:
For suppose that somehow we did manage to carry out such a calculation and suppose we found that it really is terribly improbable than our eye evolved by natural means. What would we learn from such a result?
Almost nothing. Improbable things happen all the time, you see, and the fact that something is improbable does not mean that it cannot happen.
This comes after a quote from philosopher Ingo Brigandt expressing a similar thought, and just before another similar quote from mathematician John Allen Paulos. Ewert then closes with this:
All of these critics argue that we cannot draw conclusions about Darwinian evolution from small probabilities. To be fair, many critics would not agree with these simplistic criticisms of probability arguments. They would in fact argue that evolution makes complex biological systems highly probable. It is unfortunate that these writers feel the need to disparage specified complexity, which exists to defend against an argument they would not make.
Winston Ewert was a student of William Dembski. When it comes to the art of misquotation, it seems he has truly learned at the feet of the master.
Let me begin my reply by noting that Ewert decided for some reason to change the title of my essay. The actual title was, “Can Probability Theory Be Used to Refute Evolution? (Part One).” This is significant, since it was Part Two, not Part One, that discusses the notion of specified complexity.
Part One, by contrast, had nothing to do with specified complexity. I don’t even mention it, much less disparage it. The essay wasn’t even about intelligent design. I don’t mention intelligent design at all until the very end, and I only mention it there to set up Part Two. Part One was specifically about creationist arguments, and since the ID folks are always keen to assert that they are not creationists I am surprised Ewert would make this particular error.
In the essay Ewert links to, I am discussing the especially naïve uses of probability used by creationists. Most of the essay explains why their probability calculations, which entirely ignore the role of natural selection in the evolutionary process, are simply invalid. I also explain why it is impossible to carry out meaningful calculations of the sort they require.
The part Ewert quotes is from near the end of the essay, where I note that even if by some miracle the calculation were valid, it would still tell us next to nothing since improbable events happen all the time. My very next paragraph begins with:
But perhaps the situation is not as simple as I am suggesting.
It builds up to this climax:
This suggests that, while improbability by itself does not suggest anything extraordinary, the combination of improbability with a recognizable pattern does require a special explanation. Could we use this strategy to revive our probabilistic critique of evolution?
Many proponents of Intelligent Design believe that we can. In the second part of this essay, I will show why they are wrong. We will also consider some ways in which evolutionary biologists make legitimate use of probability theory in their work.
And this brings us to the best part. I am surprised that Ewert would think that the statement he quoted makes me look bad. I suspect that Ewert, like most other ID proponents, actually agrees entirely with what I am saying there.
The whole point of talking about specified complexity was that complexity by itself is not enough to indicate design. William Dembski writes, in No Free Lunch, “Even so, complexity (or improbability) is not enough to eliminate chance and establish design (9),” and later, “One concern is that the filter assigns merely improbable events to design. But this is clearly not the case since, in addition to complexity or improbability, the filter needs to assess specification before attributing design (12).” But this is just precisely the point I was making in the statement Ewert quotes.
Of course low probability by itself does not rule out chance. This is obvious and entirely non-controversial even for ID folks. No one thinks that discovering after the fact that the human eye was improbable shows that Darwinian evolution is false, or even challenges the theory in any way.
So why is Ewert pretending not to understand that?
from ScienceBlogs http://ift.tt/1Ttip27
Aucun commentaire:
Enregistrer un commentaire