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Author
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Topic: Response to Howard Van Till
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William A. Dembski
Member
Member # 7
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posted 06. September 2002 22:44
Naturalism's Argument from Invincible Ignorance:
A Response to Howard Van Till
By William A. Dembski
Howard Van Till's review of my book No Free Lunch is available at the AAAS Evolution Resources page -- http://www.aaas.org/spp/dser/evolution/perspectives/default.htm. The actual review is available as a pdf file at http://www.aaas.org/spp/dser/evolution/perspectives/vantillecoli.pdf. I respond to Van Till's review here.
Howard Van Till's review of my book No Free Lunch exemplifies perfectly why theistic evolution remains intelligent design's most implacable foe. Not only does theistic evolution sign off on the naturalism that pervades so much of contemporary science, but it justifies that naturalism theologically -- as though it were unworthy of God to create by any means other than an evolutionary process that carefully conceals God's tracks.
Following David Griffin, Van Till distinguishes four types of naturalism. The bottom line with all these types of naturalism is that science qua science must treat nature as a causal nexus that is impervious to any empirically discernible intelligent input from outside of nature. Naturalism, whether of the metaphysical or merely methodological varieties, treats nature as complete in terms of the causal principles inherent in it. Intelligent design, by contrast, questions that completeness, arguing that there can be good reasons for thinking that events happening in nature nonetheless lie beyond the capacities inherent in nature.
There is nothing strange or even counterintuitive about this claim so long as naturalism has not, as C. S. Lewis warned, worked its way into our bones. Howard Van Till, before he became steeped in process theology, would probably have accepted this possibility as well. Is it within the natural capacities of a corpse to come back to life after all physiological function has stopped for three days? The Judeo-Christian tradition is very clear that at least when it comes to salvation history, things happen that lie beyond the capacity of strictly natural forces. But naturalism in all its guises opposes such "supernaturalism."
Supernaturalism is a problem, but not for the reasons Van Till gives. The problem with terms like "supernatural" and "supernaturalism" (and I include here Van Till's variant of "extra-natural assembly") is that they tacitly presuppose that nature is the fundamental reality and that nature is far less problematic conceptually than anything outside or beyond nature. The "super" in "supernatural" thus has the effect of a negation.
But what if nature is itself a negation or reaction against something else? For the theist (though not for the panentheist of process theology), nature is not a self-subsisting entity but an entirely free act of God. Nature thus becomes a derivative aspect of ultimate reality -- an aspect of God’s creation, and not even the whole of God’s creation at that (theists typically ascribe to God the creation of an invisible world that is inhabited among other things by angels). Hence, for the theist attempting to understand nature, God as creator is fundamental, the creation is derivative, and nature as the physical part of creation is still further downstream.
Now, from the vantage of intelligent design, treated strictly as a scientific inquiry, neither naturalism nor theism has a privileged place. Intelligent design, as a scientific research program, attempts to determine whether certain features of the natural world exhibit signs of having been designed by an intelligence. Whether this intelligence is ET or a telic principle immanent in nature or a transcendent personal agent are all, at least initially, live options. The problem with ET, of course, is that it implies a regress -- where did ET come from? The same question doesn't apply, at least not in the same way, to telic principles or transcendent personal agents because the terms of the explanation are different. ET is an embodied intelligence, and that embodiment itself needs explanation. Telic principles and transcendent agents are unembodied. That raises its own issues, but they are a different set of issues.
The key question for intelligent design is whether we can rigorously determine that an intelligence is responsible for certain features of the natural world regardless what form that intelligence takes. This very question, however, raises the possibility that occurrences in nature divide into those that require intelligence and those that don't. It's such a division that Howard Van Till wants at all costs to avoid. Instead of intelligence and nature working in tandem, Van Till limits intelligence (increasingly a process God) to endowing nature with purely natural capacities that then are on their own to work themselves out in natural history. To keep this from degenerating into deism, Van Till invokes the vocabulary of process theology, which describes God as guiding or persuading creation. But all such talk is empty. Absolutely anything that happens in the world is compatible with such divine guidance (the process God always bows to the freedom of creation; by contrast, within classical theism, creation always bows to divine freedom).
Unlike Van Till's process theology, intelligent design is not compatible with any sort of world. A world in which natural capacities can provide no empirical evidence of anything other than chance and necessity and additionally can do all of nature's design work is not a world in which intelligent design holds. But how can we tell whether natural capacities are able to account for everything that happens in nature? What evidence might count against natural capacities being able to account for all natural occurrences? And if intelligent design can show that natural capacities are in fact limited, does this not only open the door to supernatural interventions and miracles but indeed necessitate them?
Let's consider this last point, because it is one that Van Till thinks is particularly damning to my project and intelligent design generally. I argue in No Free Lunch that intelligent design does not require miracles or supernatural interventions in the classical sense of what I call "counterfactual substitution." Although the term counterfactual substitution is recent, the idea is ancient and was explicitly described in counterfactual terms by the theologian Schleiermacher. The idea is that natural processes are ready to make outcome X occur but outcome Y occurs instead. Thus, for instance, with the body of Jesus dead and buried in a tomb for three days, natural processes are ready to keep that corpse a corpse (= the outcome X). But instead, that body resurrects (= the outcome Y).
Now I claim that intelligent design, in detecting design in nature and in biological systems in particular, doesn't require counterfactual substitution. Van Till takes exception and writes: "How could the Intelligent Designer bring about a naturally impossible outcome by interacting with a bacterium in the course of time without either a suspension or overriding of natural laws? Natural laws were set to bring about the outcome, no flagellum. Instead, a flagellum appeared as the outcome of the Intelligent Designer’s action. Is that not a miracle, even by Dembski’s own definition? How can this be anything other than a supernatural intervention?"
The fault in Van Till's argument centers on an equivocation over what it means to be a "naturally impossible outcome." To see what's at stake, imagine throwing a bunch of Scrabble pieces and seeing them spell Hamlet's soliloquy. Is this a naturally impossible outcome? It certainly is highly improbable, and such improbability often leads us to attribute impossibility (a pragmatic sort of impossibility). But would such a wildly improbable event require a miracle in the counterfactual-substitution sense of impossibility? Not at all. Scrabble pieces thrown at random are not, as Van Till might put it, "set to bring about the outcome, no Hamlet's soliloquy." Randomness, by definition, has free access to the entire reference class of possibilities that is being sampled. Any possibility from the reference class is therefore fair game for the random process -- in this case, the random throwing of Scrabble pieces. It's therefore not the case that this random process was set to bring about "no Hamlet's soliloquy."
Similar considerations apply to the bacterial flagellum. It's not that nature was conspiring to prevent the flagellum's emergence and that a designer was needed to overcome nature's inherent preference for some other outcome (as in the case of counterfactual substitution). Rather, the problem was that nature had too many options and without design couldn't sort through all those options. It's not the case that natural laws are set to bring about the outcome of no flagellum. The problem is that natural laws are too unspecific to determine any particular outcome. That's the rub. Natural laws are compatible with the formation of the flagellum but also compatible with the formation of a plethora of other molecular assemblages, most of which have no biological significance.
To return to the Scrabble analogy, there's nothing in the throwing of Scrabble pieces that prevents them from spelling Hamlet's soliloquy. This is not like releasing a massive object in a gravitational field which, in the absence of other forces, must move in a prescribed path. For the object to move in any other path would thus entail a counterfactual substitution and therefore a miracle. But with the Scrabble pieces there is no prescribed arrangement that they must assume. Nature allows them full freedom of arrangement. Yet it's precisely that freedom that makes nature unable to account for specified outcomes of small probability. Nature, in this case, rather than being intent on doing only one thing, is open to doing any number of things. Yet when one of those things is a highly improbable specified event (be it spelling Hamlet's soliloquy with Scrabble pieces or forming a bacterial flagellum), design becomes the required inference. Van Till has therefore missed the point: not counterfactual substitution (and therefore not miracles) but the incompleteness of natural processes is what the design inference uncovers.
I want next to consider Van Till's concern about the applicability of specified complexity to biology. Van Till writes: "In no case do we know with certainty all relevant natural ways in which some biotic system may have historically come to be actualized." He denotes "all relevant natural causes" that might be responsible for some biotic system X by capital "N" and distinguishes this "N" from lower case "n," which for him denotes "only those natural causes that are known to be relevant." His concern is that we can only calculate probabilities for X based on n rather than N. Yet to attribute specified complexity to X, Van Till contends, we would need to calculate the probability with respect to N and show that it is small enough. He concludes: "The more we learn about the self-organizational and transformational feats that can be accomplished by biotic systems, the less likely it will be that the conditions for complexity ... will be satisfied by any biotic system."
This last statement is wishful thinking. There's no reason to think that as our knowledge of n (i.e., known natural processes relevant to the formation of X) increases, that the probabilities or complexities associated with X become more manageable and that specified complexity thereby gets refuted or dwindles away. Within Van Till's notational convention, he is suggesting that as n approximates N, P(X|n) will continually increase. But that's not how probabilities work. With increasing knowledge, the probability may stay the same or even decrease. What's more, for an omniscient being who actually knows N, P(X|N) may be smaller than we ever imagined.
Van Till's mistake here should give us pause. He admits that increasing knowledge might refute an attribution of specified complexity to some biotic system X. But if that's a possibility, then certainly it's also a possibility that increasing knowledge might fail to refute an attribution of specified complexity and might even lead to increasingly extreme assessments of complexity. What's more, there's an underlying fact of the matter about what probabilities inhere in nature, and this fact of the matter might just be that the complexity/improbability of X is indeed as extreme as it now seems. Why then does Van Till think it's "less likely" that specified complexity will be borne out for biotic systems "the more we learn"? The likelihood to which Van Till is referring here has nothing to do with objective assignments of probability or complexity to biotic systems. Rather, this likelihood merely expresses Van Till's personal conviction that naturalistic explanations must inevitably triumph. Any such likelihood is thus purely subjective and flows from Van Till's precommitment to naturalism.
But what about Van Till's worry that increased knowledge might overturn an attribution of specified complexity? Clearly, increased knowledge need not have this effect -- increased knowledge of natural processes may merely drive the probabilities still lower and thus make the complexity even more extreme. Even so, Van Till finds particularly troubling the mere possibility that new insights into the natural processes surrounding some biotic system might overturn the attribution of specified complexity to it. But why should we take Van Till's worry seriously?
A little reflection makes clear that Van Till's worry cannot be justified on the basis of scientific practice. Indeed, to satisfy his worry is to impose requirements so stringent that they are absent from every other aspect of science. If standards of scientific justification are set too high, no interesting scientific work will ever get done. Science therefore balances its standards of justification with the requirement for self-correction in the light of further evidence. The possibility of self-correction means that science can, and indeed must, work with available evidence and on that basis (and that basis alone) formulate the best explanation of the phenomenon in question. That's why the "relevant" natural processes for the formation of some biotic system are those we already know and not those waiting to be discovered. Yes, we might be wrong in attributing specified complexity to some biotic system (welcome to science -- all of whose claims are subject to revision in light of further evidence). But we also might be right. And in the absence of detailed testable models for how material mechanisms could have formed irreducibly complex molecular machines like the bacterial flagellum, our best evidence suggests that it is indeed complex and specified and that we are right in attributing design.
To attribute specified complexity to a biotic system is to engage in an eliminative induction. Eliminative inductions depend on successfully falsifying competing hypotheses (contrast this with Popper's falsification method, where hypotheses are corroborated to the degree that they successfully withstand attempts to falsify them). Now, for many design skeptics, eliminative inductions are mere arguments from ignorance, that is, arguments for the truth of a proposition because it has not been shown to be false. In arguments from ignorance, the lack of evidence for a proposition is used to argue for its truth. A stereotypical argument from ignorance goes something like "gnomes exist because you haven't shown me that they don't exist."
But that's clearly not what eliminative inductions are doing. Eliminative inductions argue that competitors to the proposition in question are false. Provided that proposition together with its competitors form a mutually exclusive and exhaustive class, eliminating all the competitors entails that the proposition is true. This the ideal case, in which eliminative inductions in fact become deductions. The problem is that in practice we don't have a neat ordering of competitors that can then all be knocked down with a few straightforward and judicious blows (like bowling pins). Philosopher of science John Earman puts it this way (Bayes or Bust, p. 165): "The eliminative inductivist [seems to be] in a position analogous to that of Zeno's archer whose arrow can never reach the target, for faced with an infinite number of hypotheses, he can eliminate one, then two, then three, etc., but no matter how long he labors, he will never get down to just one. Indeed, it is as if the arrow never gets half way, or a quarter way, etc. to the target, since however long the eliminativist labors, he will always be faced with an infinite list [of remaining hypotheses to eliminate]."
Earman offers these remarks in a chapter titled "A Plea for Eliminative Induction." He himself thinks there is a legitimate and necessary place for eliminative induction in scientific practice. What, then, does he make of this criticism? Here is how he handles it (p. 165): "My response on behalf of the eliminativist has two parts. (1) Elimination need not proceed in such a plodding fashion, for the alternatives may be so ordered that an infinite number can be eliminated in one blow. (2) Even if we never get down to a single hypothesis, progress occurs if we succeed in eliminating finite or infinite chunks of the possibility space. This presupposes, of course, that we have some kind of measure, or at least topology, on the space of possibilities." To this Earman adds (p. 177) that eliminative inductions are typically local inductions, in which there is no pretense of considering all logically possible hypotheses. Rather, there is tacit agreement on the explanatory domain of the hypotheses as well as on what auxiliary hypotheses may be used in constructing explanations.
I want here to focus especially on Earman's idea that elimination can be progressive. Too often critics of intelligent design charge specified complexity with underwriting a purely negative form of argumentation. But that charge is not accurate. The argument for the specified complexity of the bacterial flagellum, for instance, makes a positive contribution to our understanding of the limitations that natural mechanisms face in trying to account for it. What justifies us in attributing specified complexity to the bacterial flagellum? The bacterial flagellum is irreducibly complex, meaning that all its components are indispensable for its function as a motility structure. What's more, it is minimally complex, meaning that any structure performing the bacterial flagellum's function as a bidirectional motor-driven propeller cannot make do without certain basic components.
Design theorists are therefore closing off possible avenues by which such systems might have evolved naturalistically. In particular, they've shown that no direct Darwinian pathway exists that incrementally adds these basic components and therewith evolves a bacterial flagellum. Rather, an indirect Darwinian pathway would be required, in which precursor systems performing different functions evolve by changing functions and components over time (Darwinists refer to this as coevolution and co-optation; Van Till gestures at such an indirect pathway when he invokes the type III secretory system as an evolutionary precursor to the flagellum -- more on this later). Plausible as this sounds to the committed naturalist, there is no evidence for the efficacy of indirect Darwinian pathways to accomplish irreducible and minimal complexity. What's more, evidence from engineering strongly suggests that tightly integrated systems like the bacterial flagellum are not formed by trial and error tinkering in which form and function coevolve. Rather, such systems are formed by a unifying conception that combines disparate components into a functional whole -- in other words, by design.
In assessing whether the bacterial flagellum exemplifies specified complexity, the design theorist is tacitly following Earman's guidelines for making an eliminative induction work. Thus, the design theorist orders the space of hypotheses that naturalistically account for the bacterial flagellum into those that look to direct Darwinian pathways and those that look to indirect Darwinian pathways (cf. Earman's requirement for an ordering or topology of the space of possible hypotheses). The design theorist also limits the induction to a local induction, focusing on relevant hypotheses rather than all logically possible hypotheses. The reference class of relevant hypotheses are those that flow out of Darwin's theory. Of these, direct Darwinian pathways can be precluded on account of the flagellum's irreducible and minimal complexity, which entails the minuscule probabilities required for specified complexity. As for indirect Darwinian pathways, the causal adequacy of intelligence to produce such complex systems (which is simply a fact of engineering) as well as the total absence of causally specific proposals for how they might work in practice eliminates them. In eliminating indirect Darwinian pathways, design theorists are therefore not merely eliminating what thus far hasn't worked (coevolution and co-optations) but also appealing to causal powers (designing intelligences) that are known to work.
Is this enough to justify asserting that the bacterial flagellum exhibits specified complexity? For the diehard naturalist (and I include here naturalistic theists like Howard Van Till), such an eliminative induction will never be enough and always constitute an argument from ignorance. But in refusing to countenance eliminative inductions that establish specified complexity, naturalists are guilty of their own argument from ignorance. Fearnside and Holther, in their classic Fallacy -- The Counterfeit of Argument, call it the argument from "invincible ignorance." Alternatively, they refer to it as "apriorism."
According to Van Till, design theorists have failed to take into account indirect Darwinian pathways by which the bacterial flagellum might have evolved through a series of intermediate systems that changed function and structure over time in ways that we do not yet understand (hence his appeal to the type III secretory system). But is it that we do not yet understand the indirect Darwinian evolution of the bacterial flagellum or that it never happened that way in the first place? At this point there is simply no evidence for such indirect Darwinian evolutionary pathways to account for biological systems that display irreducible and minimal complexity.
Is this, then, where the debate ends, with design critics like Van Till chiding design theorists for not working hard enough to discover those (unknown) indirect Darwinian pathways that lead to the emergence of irreducibly and minimally complex biological structures like the bacterial flagellum? Alternatively, does it end with design theorists chiding design critics for deluding themselves that such indirect Darwinian pathways exist when all the available evidence suggests that they do not. Although this may seem like an impasse, it really isn't. Science must form its conclusions on the basis of available evidence, not on the possibility or promise of future evidence. This means that eliminative inductions need to be local inductions, based on detailed testable models and hypotheses that are currently available.
If evolutionary biologists can discover or construct detailed, testable, indirect Darwinian pathways that account for the emergence of irreducibly and minimally complex biological systems like the bacterial flagellum, then more power to them -- intelligent design will quickly pass into oblivion. But until that happens, the eliminative induction that attributes specified complexity to the bacterial flagellum constitutes a legitimate scientific inference. The only way to deny its legitimacy is by appealing to some form of apriorism. The apriorism of choice these days is, of course, naturalism. And that apriorism engenders an argument not just of ignorance but of invincible ignorance. Indeed, any specified complexity (and therefore design) that might actually be present in biological systems becomes invisible as soon as one consents to this apriorism. If biological systems actually are designed, not only won't Van Till see it but he can't see it. This is invincible ignorance.
The remainder of Van Till's criticisms of No Free Lunch can be dispatched more quickly:
(1) Van Till is concerned that my use of chance encompasses all natural processes. But as he knows, I approach natural processes as a mathematician, and natural processes are modeled mathematically using stochastic processes. At any rate, Van Till's quibble is not with my definition but with the label to which I'm assigning the definition.
(2) Van Till claims that my probabilistic analysis of the bacterial flagellum is "radically out of touch with contemporary genetics and developmental biology." I'm not sure what developmental biology has to do with it (bacteria don't have embryos that develop into adults). As for genetics, he would have preferred to see the probabilistic analysis of the flagellum center on the genes that code for its proteins rather than the proteins that go into its assembly. But the genes follow the proteins which follow the function, and not vice versa, so my analysis is the correct one. Even so, since genes map to proteins, the probabilities assigned to the flagellum's proteins and assemblage can easily enough be backtracked to the genes themselves (this is standard probability theory, in which probabilities on the space mapped into backtrack to probabilities on the space mapped out of).
(3) Van Till is confused about how the detachability condition applies if the probabilistic analysis of the flagellum is confined to the genome. As he sees it, if the search for a detachable pattern is directed toward the base-pair sequence coding for the flagellum, then any such pattern could not be detached from the actual occurrence of that sequence. But this is false. The pattern is that collection of sequences which codes for a functioning bidirectional motor-driven propeller. This is no different from a cryptographic scheme in which the plaintext (cf. protein assemblage) is detachable only if the ciphertext (cf. base-pair sequence) that maps onto it is likewise detachable.
(4) Van Till seems to think that because the historical pathways by which biological systems evolved are almost invariably occluded, this gives credence to mechanistic theories of evolution. He writes: "Full causal specificity is, of course, the goal of all scientific explanations, but it is often very difficult to achieve, especially in the reconstruction of life’s formational history. That’s just a fact of life in evolutionary biology, as well as in many other areas of science." To see this absence of evidence as providing support for biological evolution itself constitutes an argument from ignorance. The only way to test whether material mechanisms are capable of driving biological evolution is by placing it in competition with something like intelligent design. Van Till's naturalism conveniently closes the door to any such competition.
(5) Van Till has a problem with my characterization of the bacterial flagellum as a discrete combinatorial object. Nonetheless, that's what it is. Moreover, the probability I describe for such objects, which decomposes into a product of an origination, localization, and configuration probability, does in fact constitute the probability for such objects. That decomposition holds with perfect generality and does not presuppose any independence or equiprobability assumptions. Now, how one assigns those probabilities and sorts through the different possible estimates of them is another matter. Thus, for Van Till to remark that "no biologist has ever taken the bacterial flagellum to be a discrete combinatorial object that self-assembled in the manner described by Dembski" is besides the point. The bacterial flagellum is indeed a discrete combinatorial object, and the self-assembly that I describe is the one we are left with and can compute on the basis of what we know. The only reason biologists would refuse to countenance my description and probabilistic calculations of self-assembly is because they show that only an indirect Darwinian pathway could have produced the bacterial flagellum. But precisely because it is indirect, there is, at least for now, no causal specificity and no probability to be calculated. Design theorists are closing off possible mechanistic routes for biological evolution. Van Till's biologists, by contrast, handwave at mere conceptual possibilities.
(6) In line with the previous concern, Van Till offers the type III secretory system as a possible precursor to the bacterial flagellum. This ignores that the current evidence points to the type III system as evolving from the flagellum and not vice versa (cf. Milt Saier's recent work at UCSD). But beyond that, finding a component of a functional system that performs some other function is hardly an argument for the original system evolving from that other system. One might just as well say that because the motor in a motorcycle can be used as a blender, therefore the motor evolved into the motorcycle. Perhaps, but not without intelligent design. Even if it could be shown that the type III system predated the flagellum (contrary to Milt Saier's work), it could at best represent one possible step in the indirect Darwinian evolution of the bacterial flagellum. But that still wouldn't constitute a solution to the evolution of the bacterial flagellum. What's needed is a complete evolutionary path and not merely a possible oasis along the way. To claim otherwise is like saying we can travel by foot from Los Angeles to Tokyo because we've discovered the Hawaiian Islands. Evolutionary biology needs to do better than that.
(7) Van Till would have liked more detail showing that how bacterial flagellum is specified. Briefly: consider the reference class of possibilities to be all molecular assemblages (to keep things manageable let's limit them to a billion subunits). Now consider the pattern "bidirectional motor-driven propeller." This is a specification (I leave this as an exercise to the reader). Now do a perturbation tolerance and identity analysis as I describe it in section 5.10 of No Free Lunch. This restricts both the reference class and the specification to the actual flagellum for E. coli. Moreover, it allows us to estimate the probabilities for the naturalistic formation of the flagellum in line with John Leslie's fly-on-the-wall methodology.
(8) Finally, Van Till attributes an argument to me that I never made. He writes: "If, as Dembski implicitly accepts, forming the majority of the E. coli genome -- including the portion dedicated to the actualization of the type III secretion apparatus -- did not need the form conferring intervention of a designer, then why would intervention be necessary for the small additional portion that codes for a flagellum?" I argue that the bacterial flagellum is designed because it exhibits specified complexity. But such an argument says nothing about the design or absence of it in the rest of the bacterium. Design and specified complexity must be established on a case-by-case, system-by-system basis. Moreover, the design of one thing need not preclude the design of another. I can, for instance, argue that the cassette player in my car is designed. But that leaves the design of the rest of my car untouched. Thus, when Van Till asks, "Does it not seem odd that the flagellar 2% needed supplementary designer-action while the other 98% did not?" he is certainly correct that it is odd. But the oddness here is of Van Till's own doing, attributing to me a position that I don't hold and for which I never argued.
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I close with a quote by the late philosopher Willard Quine. Quine, though a naturalist, was not wedded to the methodological and metaphysical naturalism of Van Till. Quine was a pragmatic naturalist. This pragmatism allowed him to entertain the following possibility: "If I saw indirect explanatory benefit in positing sensibilia, possibilia, spirits, a Creator, I would joyfully accord them scientific status too, on a par with such avowedly scientific posits as quarks and black holes" (from "Naturalism; or, Living within One's Means," Dialectica 1995, vol. 49).
Quine's pragmatic naturalism is far more intellectually nimble than Van Till's naturalism, which, as we've seen, is scientifically stultifying and when pushed to extremes, as Van Till does, commits an argument from invincible ignorance. I would, therefore, that the scientific community take seriously the possibility raised by Quine of joyfully according intelligent design full scientific status. At issue is not the endless list of quibbles that Van Till raises, but whether intelligent design can confer explanatory benefit in understanding biological systems. That is now happening. To be sure, design theorists still have their work cut out. But it is an intellectual project that is fast gaining momentum and that promises shortly to displace Van Till's naturalism.
Van Till's naturalism is not an aid to intellectual clarity but a wet blanket designed to stifle inquiry. Not only is his naturalistically inspired critique consistently off the mark, but it makes a virtue of maintaining the status quo. The problem with web blankets and the status quo is, or course, that they are boring. Intelligent design, by contrast, as Karl Giberson and Donald Yerxa point out in their forthcoming Species of Origin (Rowman & Littlefield, 2002), is setting the agenda for the origins question in biology (and specifically for the emergence of biological complexity). Scientists therefore have a choice to make: to consider the possibility of intelligent design as a live option (if only for pragmatic reasons like Quine's) or to retreat into a naturalistic apriorism that eternally blinds itself to the very possibility of design. The choice here is between unfettered inquiry (with all the risks that entails) and invincible ignorance (with all the security and boredom it confers). It's clear which option Van Till has chosen.
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nobody
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posted 07. September 2002 03:06
quote:
Van Till's naturalism is not an aid to intellectual clarity but a wet blanket designed to stifle inquiry. Not only is his naturalistically inspired critique consistently off the mark, but it makes a virtue of maintaining the status quo. The problem with web blankets and the status quo is, or course, that they are boring. Intelligent design, by contrast, as Karl Giberson and Donald Yerxa point out in their forthcoming Species of Origin (Rowman & Littlefield, 2002), is setting the agenda for the origins question in biology (and specifically for the emergence of biological complexity). Scientists therefore have a choice to make: to consider the possibility of intelligent design as a live option (if only for pragmatic reasons like Quine's) or to retreat into a naturalistic apriorism that eternally blinds itself to the very possibility of design.
I agree completely. The attempts to stifle inquiry seem quite blatant in some cases, to me. I don't think they will ultimately succeed though.
As for being blind to intelligent design, your comment reminds me a great deal of the old story about some Church officials and Galileo's telescope. They were afraid of what they would see. Nowdays we have some in science who are doing the rough ID equivalent of refusing to look through the telescope.
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Moderator
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posted 07. September 2002 12:05
Second Warning to Nobody:
I've already warned you about short posts in the past. They are especially distressing when you use them to take potshots at certain groups of people.
This is the last warning before we ban you for 30 days. Either make substantial, good-natured posts, or don't post on our board.
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nobody
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posted 07. September 2002 12:21
Sorry. I certainly never intended to cause you a problem here. I guess I need to take a break.
Bye.
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Frances
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posted 08. September 2002 23:14
Dear William,
I will be using your response to van Till as the stepping stone to accept your offer for me to present an alternative ID filter which includes as one of the inferences, "we don't know". This filter is based on the work of Wilkins and Elsberry as published recently (Wilkins, J. S. and W. R. Elsberry (2001). "The advantages of theft over toil: the design inference and arguing from ignorance." Biology and Philosophy 16(November): 711-724)
I will be on vacation until the end of the month but I would like to present the forum with a preview of my argument.
I believe that Dembski, in his latest response to van Till, has identified a major short comming in the ID filter as proposed in the design inference and No free Lunch.
When van Till points out that one has to differentiate between an inference based on all natural cases versus known natural causes. Van Till denotes the former one with N and the latter one with n. Dembski argues that if our knowledge increases the probability may in fact decrease rather than increase. One may argue however that science has been quite exemplary in showing that in many cases the probability increased when a natural explanation was found for something which was initially attributed to design. History is full of examples. The question remains, may there be examples in which science will fail? Surely that possibility can not be eliminated but science unlike ID does not deal in proof by elimination.
So we need to accept that there will be instances in which our lack of knowledge may lead us to infer design where design is not the explanation when we gain a fuller understanding of the facts.
We also may find that our lack of knowledge is not going to be resolved by science and we may have to infer design. In such cases however should we infer design or chance? Why should one be privileged over the other? Yet Dembski seems to suggest that ID has to deal only in known processes, not yet to be discovered processes, but if I am correct then ID has opened itself up to false positives. Indeed the best way to avoid false positives is to allow "we don't know" as an explanation.
Another important factor to consider is that ID is inherently based on elimination and thus has no predictive powers, does not provide us with mechanisms, historical pathways. I would say that using Dembski's own arguments "in the absence of detailed testable models for how ID could have formed IC formed irreducibly complex molecular machines like the bacterial flagellum, our best evidence suggests that it is indeed complex and specified and that we are right in attributing XXX".
After all why should ID be given a priveleged position over science? Why should our ignorance potentially lead to an ID inference. Should we not hold ID to the same standards to which it hold science namely detailed testable models? Detailed pathways?
Perhaps we should consider Elsberry and Wilkins suggestion that we should not be afraid to acknowledge our ignorance rather than let it lead to conclusions which may or may not be correct. Until we have more data that shows more detailed models, we should consider it to be in a category of "we don't know (yet)"
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William A. Dembski
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posted 08. September 2002 23:41
Briefly to Frances:
(1) Then why not withhold judgment in the Contact example and simply attribute a long sequence of prime numbers from outer space to unknown causes? The problem is that Wilkins and Elsberry's revised filter scotches all design inferences and not just the ones they don't like in biology. For the ID critic, the answer is not to revise the filter but to try to substitute a different picture of scientific rationality (e.g., Sober's likelihood approach). But that is deeply problematic itself.
(2) With regard to false positives, to say that the design filter does not commit false positives if there is specified complexity remains true. And to say that an attribution of specified complexity may be mistaken is also true -- and not inconsistent with the latter claim. There's a difference between specified complexity as it subsists in nature and our knowledge of it. You might want to reread my post about what sort of property is specified complexity.
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Frances
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posted 09. September 2002 00:25
I would not want to use the 'Contact' example, which is truely fictional, as a useful example. Rather than resort to (science) fiction we should focus on the issue in biology. But as a side note I would like to point out that there may be natural causes that would lead to 'prime numbers' occuring in nature.
Yet we have a good real life example when the pulsars were first discovered. Initially the design inference seems to have gained some power. When our knowledge increased, the design inference was quickly dropped in favor of the scientific explanation of pulsars.
As far as Dembski's claim is concerned, only when we can eliminate all known and unknown pathways and we can infer the there is specified complexity can we conclude that there is design. To claim though that there is no false positives with the design inference presumes that we can eliminate all such hypotheses.
My claim is that until we have some positive evidence of design, or we have eliminated all hypotheses we should not jump to a conclusion of intelligent design.
What Elsberry and Wilkins filter does is to not give the design inference a priviliged position but instead requires the same probabilistic analysis that is applied for chance hypotheses. The problem is that this would require ID proponents to provide for positive evidence for their thesis but that seems to be fair if the same is required from chance hypotheses?
As I understand NFL, it was an attempt to by pass the requirement to have to eliminate all and any chance hypotheses since it was claimed that chance could not generate CSI. However with the recent understandings of the NFL theoremes it seems that likely chance algorithms etc do not fall under the NFL theorem.
In the end efforts to show the limitations of Darwinian mechanisms is not going to help further a design inference, imho, unless the design inference is based on the same approaches as used in science, that is we hold the design inference to the same standards as the chance hypotheses, show us the detailed pathways allowing us to apply probabilistic approaches to see which of the hypotheses is most likely.
After all the only way to teach the controversy is being able to teach what intelligent design is, not what it isn't.
Evidence against the prevailing hypotheses should not be seen as convincing evidence for ID unless we have independent evidence.
Let me make the first step here: As a scientist I am not afraid to admit that "I don't know (yet)". And as a scientist it is this unknown that drives me to do new research, propose new hypotheses.
[ 09 September 2002, 01:06: Message edited by: Frances ]
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Cre8ionist
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posted 13. September 2002 19:04
Frances,
I'd just like to comment on part of your last post, namely:
quote:
My claim is that until we have some positive evidence of design, or we have eliminated all hypotheses we should not jump to a conclusion of intelligent design.
The second part first, haven't IDers/creationists been asking this all along of Darwinists? I mean, unless we've eliminated "all hypotheses" we should not jump to a
conclusion of neo-Darwinism. Yet, in most of the schools this is precisely what's been done, as Wells has so clearly demonstrated.
And as to the claim of positive evidence, A. E. Wilder-Smith pointed out positive evidence decades ago, Dean Kenyon recognized it, many others including Michael Behe have pointed to positive evidence for design, yet commited Darwinists continue to ask for it. My question is this what kind of evidence would you expect to find in the universe
if it were set up as a habitat for life as we know it?
IDers obviously think the minimum requirements for the design hypothesis have been met, and we are asking that science and scientists in general refrain from jumping to the conclusion that Darwinism alone accounts for the specificity of life.
[ 14 September 2002, 15:48: Message edited by: Cre8ionist ]
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Frances
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posted 14. September 2002 18:47
Creationist,
I disagree with your statement. Contrary to intelligent design, Darwinism did propose the mechanisms allowing hypotheses to be formulated. Wells has demonstrated little more than a less than full understanding of the facts surrounding 'icons'. I have delved for instance into the peppered moth story and much of Wells' claims are without merrit. But lets not get distracted and focus on the scientific claims.
So let me restate the obvious:
ID: Elimination of all competing hypotheses. No attempt to provide positive evidence of pathway, intent, mechanism etc.
Darwinism (and in fact most if not all scientific endeavours): Formulation of hypotheses which are then attempted to be falsified. When hypotheses withstand falsification over time we may consider them theories or even 'facts'.
What may I ask is the positive evidence of design? Behe pointed out IC systems but we all know now that ICness is not a reliable indicator of design per se and still relies on elimination of darwinian pathways and other pathways. ICness does not have much relevance to a positive evidence effort for design imho.
Please formulate the design hypothesis and show positive evidence supporting its claims. That is it does not rely on elimination of alternatives and provides a better interpretation of the available data than competing hypotheses.
I think that many IDers like you may need to realize that science does not jump to conclusions such as "Darwinism alone accounts for the specificity of life". In fact science already knows that there are non-Darwinian mechanisms that play a role as well.
None of the evidence however shows a positive evidence of an designer beyond natural processes.
I understand that ID proponents were asked what they would teach in support of ID. Perhaps you can tell us a positive research program based on ID that could not arise under present scientific approaches. That is, show that ID has something to offer beyond Darwinian mechanisms cannot explain this.
Dembski's ID inference is based on the elimination of all known (and unknown) chance hypotheses to allow one to infer design. My argument is simply that we should not give ID a priviliged position of being the default if our knowledge fails. And why don't we approach the filter from the following perspective: Show that chance and design can be eliminated in which case we can infer regularity.... Why would such a filter be less acceptable than Dembski's. In fact I would argue that it would be more acceptable since we also have positive hypotheses on how regularity may have done it.
So rather than make design or regularity/chance privileged we should consider that a situation in which we have no competing ID hypothesis which provide for detailed pathways (after all this is what Dembski seems to require of Darwinian pathways), then in absence of present knowledge on regularity pathways we should just accept our ignorance, not infer design just because we do not know...
Until ID can provide for a positive approach, it is doomed to fail as a scientific contribution. Which may explain the recent change of heart of those calling for it to be taught aside science. Now they seem to propose a more realistic, social sciences curriculum as the best place.
So do IDers really believe that the minimum requirements have been met? Given the above change of heart I would say unlikely. It also seems that other IDers who were at the forefront of the controversy have softened their stance.
Bruce Gordon comes to
mind
quote:
Design theory has had considerable difficulty gaining a hearing in academic contexts, as evidenced most recently by the the Polanyi Center affair at Baylor University. One of the principle reasons for this resistance and controversy is not far to seek: design-theoretic research has been hijacked as part of a larger cultural and political movement. In particular, the theory has been prematurely drawn into discussions of public science education where it has no business making an appearance without broad recognition from the scientific community that it is making a worthwhile contribution to our understanding of the natural world.
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Cre8ionist
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posted 15. September 2002 17:31
Frances,
quote:
ID: Elimination of all competing hypotheses. No attempt to provide positive evidence of pathway, intent, mechanism etc.
Darwinism (and in fact most if not all scientific endeavours): Formulation of hypotheses which are then attempted to be falsified. When hypotheses withstand falsification over time we may consider them theories or even 'facts'.
Without having to get into quote wars, I think it could be shown that Darwin's theory
was in fact originated for the purpose of eliminating ID/ "Natural Theology" if you will.
Further, it could be shown that certain high profile evolutionists have acknowledged that the Divine foot must not be allowed into the door(of science). Thereby seeking to insulate their theory from critique and eliminate design as an alternative.
Lastly, falsification is something which has been shown to be difficult to use for some type of scientific demarcation, consider the hypothesis that life has originated through non-intelligent processes for example, what experiment would you propose I do to falsify this notion? Or similarly,what experiment would you propose I do to falsify the hypothesis that there is not just a single universe, but that there are instead a multitude of universes i.e., multiverses?
Yet, who claims that these non-falsifiable hypotheses are not to be mentioned in the textbooks?
But in keeping with the intentions of this forum I should address the following:
quote:
Perhaps you can tell us a positive research program based on ID that could not arise under present scientific approaches. That is, show that ID has something to offer beyond Darwinian mechanisms cannot explain this.
First, I don't want to be trapped by the form of your request. I don't think that
ID is under any obligation to replace Darwinism as a research program. If it's the explanation for how we arrived here then whether or not it produces as much "positive" research as Darwinism is a separate question to the origins one. That being said, I do think there are definite positive areas of research within ID, and I also think that much of the research being done under Darwinian scientists would still be done. Since as Behe pointed out, most scientific research is done without respect to Darwinian evolution. For example, discovering new organelles, such as de Duve did had nothing to do with evolution, yet, in my opinion, discovering their function had everything to do with intelligent design. Which leads me to the point, discovering function and then the methods of arriving at function should lead to quite abit of fruitful research.
In 2001 a U.S. Navy EP-3 made an emergency landing in China after a mid-air collision, most people probably remember it. One of the biggest fears of the U.S. was that if the plane was left too long, the plane could be duplicated by the Chinese through reverse engineering, as had been done previously by the Soviets when they laid hands on a B-29 Superfortress and made the Tu-4 from what they learned. Cnn said this of the Navy EP-3 :
quote:
American officials are concerned that sensitive
technical information could be copied or that the
entire airplane could be replicated if it is never
given back -- a tactic known as reverse
engineering that has been used over the years to
enhance a country's defense capabilities.
Now what would have happened if the Chinese looked at the technology in the EP-3 and tried to duplicate it only through functional intermediates? Well, I submit they'd be at it for a long long time, never really acomplishing their goal. I think this is similar to what's being done in most origin of life research and also in the research relating to the origin of organelles, organs etc.
Instead, I think the focus should be on building the given cellular machine from the data retrieved from reverse engineering without regard to alleged intermediates and I think the research would be far more fruitful. For instance, origin of life researchers have spent countless hours on proteinoids, coacervates and microspheres, when this time, in my opinion would have been better spent leap frogging these alleged intermediate stages.
BTW, it only took the Soviets 2 years to duplicate the B 29.
Looks like I'll have to cut
this short, quickly, one other thing that you said which I wanted to comment on was that Contact was "truly fictional." While this movie account is fictional, the SETI research program is not fictional and the methods they use are scientific. So to say that Contact is fictional is to miss the point. The research scientists involved in SETI believe they'll be able to reliably discern between natural and intelligent signals. This is fundamentally plausible, likewise it is fundamentally plausible that we can reliably discern the difference between naturally formed or adapted biological structures and intelligently designed biological machines. Through the application of Dembski's work, Michael Behe's irreducible biological complexity meets information theory and is backed up, as it were, by another field.......Cre8
[ 15 September 2002, 22:51: Message edited by: Cre8ionist ]
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Elend
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posted 16. September 2002 04:03
Cre8ionist quote:
Without having to get into quote wars, I think it could be shown that Darwin's theory
was in fact originated for the purpose of eliminating ID/ "Natural Theology" if you will.
In fact all newer scientific theories are proposed to improve old theories (or even eliminate them). Being an older theory is by no means a quality. But anyway, this was not the point Frances was making. (In any case I doubt Darwin's theory originated for the purpose of eliminating ID - it simply explained better, in more detail what might have happened, or does happen. Moreover, how on Earth can you eliminate ID if in principle it can explain everything - including Darwinian evolution?)
Back to "elimintation". What Frances was claiming (I think) was that ID looks at a design, shows that pathways A, B, and C are impossible, therefore concluding D (itelligent design) is the correct one. It does not attempt to prove D by itself. Furthermore, it does not take into account possible E,..., Z pathways. Where as non-eliminative theories (say darwinism) can predict certain results without taking into account other existing theories, ID MUST take into account all existing theories in order to show that they are wrong, and conclude itself is correct.
To a different point. I have no idea why you people have such a fixation on Contact. If the signal was composed exclusively of those prime numbers, its origin would have remained a mystery. It is THE REST of the message that finally proved its intelligent source.
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Cre8ionist
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posted 16. September 2002 09:10
Elend, you seem to be saying that elimination in the sense you speak of is always wrong? Is it wrong when you see a scrabble board with numerous connected words on it, to eliminate chance?
I think not, in that case, design would be, as Dembski shows, the best explanation.
Contact is not the point, it's an example, an example of design detection. I've used the
australopithecine/monolith scene from 2001 before myself. Examples like this appeal to our intuition that design is indeed detectable. As you yourself state, eventually, those researchers in Contact did implicate design, Dembski's given criteria for nailing this down.
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John Wilkins
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posted 19. September 2002 01:56
Dembski has asserted that Elsberry and I do not allow the detection of design in our reworking of his filter. I wonder if he has read the paper? We explicitly state that we can detect design. Of the "dont-know-yet" branch that we discuss introducing at first, we said:
quote:
Perhaps, then, we need another branching at each decision, leading to "Don't-know-yet". As Dembski's probabilities are Bayesian assignments made on the basis of a set of prior knowledge and default hypotheses, this seems to be a perfectly reasonable move. However, it has one glaring problem - it blocks any inferences of design, and that is too much. There are well attested cases of design in the world: we humans do things by design all the time. So an explanatory filter had better not exclude design altogether. How can it be included here? When is a design inference legitimate?
We do go on to say:
quote:
The way we find out such things about designers is to observe and interact, and if we can, converse, with them. In this way we can build up a model of the capacities and dispositions of designers.
...
So a revision to Dembski's filter is required beyond the first "Don't-know" branch. This sort of knowledge of designers is gained empirically, and is just another kind of regularity assignment. Because we know what these designers do to some degree of accuracy, we can assess the likelihood that E would occur, whether it is the creation of skirnobs or the Antikythera Device. That knowledge makes E a HP event, and so the filter short-circuits at the next branch and gives a design inference relative to a background knowledge set Bi available at time t. So now there appears to be two kinds of design - the ordinary kind based on a knowledge of the behavior of designers, and a "rarefied" design, based on an inference from ignorance, both of the possible causes of regularities and of the nature of the designer.
This is fairly clear. I object to the way Dembski has interpreted our paper.
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kyle7
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posted 21. September 2002 04:00
John,
We should ask if ID methods are useful for the scientific community. I would say that the CSI construct holds great promise by constraining us to the realm of science. Oftentimes Neo-Darwinists will propose pathways of say A going to B without a scientific basis. Sadly, this relegates Neo-Darwinism outside the realm of science bringing discredit to the theory. Saying, "We have faith that a mechanism and pathway will be found" does not strengthen ones theory. The Design Inference forces us to examine all known physical phenomena to see if it is statistically plausible to explain the transition. If it is not plausible, then the only other conclusion is design.
You find fault with ID given that it is not possible to entirely eliminate design. The same can be said of Naturalist explanations of life or other objects. You may find a car in the desert and want to keep it because you claim it is "natural". The possibility does exist that the atoms randomly came together forming the car. If a person stepped forward and lay claim to the car, due to the license plate, one could always postulate that the atoms happened to assemble forming the same license plate. As with design, it is not entirely possible to eliminate naturalistic explanations. Any rational person would doubt the story that the car naturally formed. But, why would they doubt the story? Certainly, it is possible for the atoms to randomly come together! We would doubt the story given the probability of the event happening - it is extremely unlikely. We don't need to know anything about the designer to come to this conclusion. Similar arguments apply to Darwinism.
Another claim you make is the lack of evidence for design. Using Dembski's Design Inference, all we have to do is follow the Generic Chance Elimination Argument (GCEA) and show that the probabilities are significantly small for Darwinian Evolution. The small probabilities coupled with the specification ARE evidence for design. Darwinists must be able to show the possibility that billions of small transitions lead from single-celled-organisms all the way to the diverse multitude of life-forms that have ever existed. Dembski's Design Inference Method can be used in a multitude of ways to show the evidence for design. You seem to think that the Design Inference is faulty because there may exist unknown phenomena that may explain the pathways. You must also have a problem with the Second Law of Thermodynamics. One statement of the law is the following:
"It is impossible for a cyclically operating device to convert thermal energy to mechanical energy without wasting some thermal energy to the cold surroundings."
Have we tested all engines to guarantee that this statement is true? Could there not exist some undiscovered engine that would violate this law? Now if you are consistent then you must either accept Dembski's Design Inference as a valid tool or reject the Second Law of Thermodynamics. Which will you do?
[ 21 September 2002, 04:15: Message edited by: kyle7 ]
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Frances
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posted 21. September 2002 05:55
Kyle7: If you consider proposals (hypotheses) of pathways to be outside the realm of science then surely proposals that consider that such pathways do not exists are equally unscientific?
My problem with your argument is that you consider speculation to be outside the realm of science. When science has not yet found an explanation for an observation you propose that we should infer design rather than admit our ignorance.
Your claim that a car in a dessert is similar in its argument as Darwinism reveals the problem with analogies.
Finally to consider the second law of thermodynamics to be on equal footing with the design inference is a bit overreaching. So rather than accept your two choices, accept design inference or reject the SLOT I chose a third one, reject your argument.
Or perhaps you can show us an example in which Dembski's filter worked to detect design in biology?
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