Debating Darwin and Design
A dialogue between two Christians
Is Intelligent Design science or ‘creationism in a cheap tuxedo’?
8th November 2013
Francis Smallwood - Fourth response
I am delighted that Joshua and I have resumed our dialogue after an unwittingly protracted hiatus of some twenty months. Whilst we were both fairly appalled by the length of time which has elapsed since our last responses, the intermission has allowed us to think, read and talk more and so we shall (hopefully) be clearer now on a few matters. My own views have changed and developed regarding certain issues, and I hope to be able to offer some more cogent and substantive arguments than some of those I have previously propounded. I look forward to continuing this interesting and multifarious debate with Joshua, a great friend, uniting as it does ‘the two greatest and purest pleasures of human life, study and society.’
Introduction and overview
When Joshua and I were planning this discussion we decided that we would begin with the question with which we are currently concerned, a question which attracts a great deal of attention in the debate over ID, even though it is not the case that ID must be science or creationism as it could be neither. Joshua considered that ‘Perhaps we have gone about this discussion the wrong way round, choosing to debate the classification of ID before the merits of ID,’ adding, ‘I don’t see that it really matters.’ I am inclined to think that it does matter, as in asking whether or not ID is science we are presupposing that we know what claims ID makes, which I shall argue we do not. As Sahotra Sarkar remarks, ‘before we can fruitfully discuss whether ID is science or not, we need a positive account of what design and intelligence are.’ ID theorists have so far failed to provide such an account.
In Joshua’s previous response he helpfully précised the discussion so far and enumerated seven ‘lines of attack’ taken by critics of ID to argue that it is not science. I shall reproduce Joshua’s list here for convenience:
- By showing that design and creation, as concepts, are necessarily synonymous.
- By showing that, historically, ID emerged from the same source as creationism.
- By bringing up the infamous Dover trial.
- By showing that ID proponents are religiously motivated.
- By showing that ID theorists don’t publish their work in peer-reviewed journals.
- By showing that methodological naturalism (MN) is an essential part of science. This includes the prohibition of supernatural causation. ID necessarily has theological implications and thus violates the principle of MN.
- By showing that ID doesn’t follow ‘the scientific method’ and is neither falsifiable nor verifiable.
Of these, I do not believe that (1) through (5) offer legitimate means of denying ID scientific status, although, regarding (5), if ID represents the scientific breakthrough which its proponents claim it does, then it is surely surprising that the majority of the scientific community should have failed to appreciate its import and treated the theory with such manifest disdain. Regarding (6), methodological naturalism (the view that when doing science we should seek only explanations which refer to natural, law-governed causes), I shall argue, is essential to modern science. Inasmuch as ID flouts this principle, it is at variance with the rest of modern science, giving us a reason to deny that ID is science. Regarding (7), whilst there is an undeniable difference between science and other modes of inquiry (e.g., history, philosophy, theology, etc.) a successful demarcation criterion has—and not for want of effort—so far eluded philosophers of science. Both verifiability and falsifiability have been shown to be beset with problems and whilst testability is a stronger candidate criterion it is similarly problematic. I shall argue that, assuming that the notion of ‘intelligent design’ is intelligible (which I shall go on to argue that it is not), ID is untestable, contrary to the claims of ID theorists, since we lack auxiliary information about the goals and abilities of the designer which is required to conjoin with the design hypothesis to derive observational implications. I shall not, however, from this conclude that ID is not science since it is conceivable that this information may become available. One could not justifiably claim that this information could never become available without foreknowledge of future inquiry.
Whatever objections may be raised against ID in relation to naturalism and demarcation criteria, I agree with Sarkar that disquisitions on such topics are controversial, and that because of their controversiality they are liable to obscure the deeper problems with ID, allowing its proponents to ‘camouflage the basic incoherence of their claims.’ According to Sarkar, ID is not science ‘mainly because we simply do not know what it is saying.’ The real problem with ID is its theoretical indigence. Given the lack of positive theory, it is hardly surprising that ID is untestable, predictively (or retrodictively) infertile and explanatorily impotent. ID ultimately founders on account of its insubstantiality. ID is not a rival theory to Darwinism (a term which I shall use interchangeably with ‘evolutionary theory’) simply because there is barely any theory at all—only a rehashing of the old argument from design shorn of its explicitly theological content, couched in information-theoretic terms and applied to biochemistry. ID theorists gleefully pronounce the demise of Darwinism on account of its unsolved problems and enjoin that it be abandoned and ID embraced, even though we have not been told what exactly ID theory is or given any reason to think that it offers a better alternative. To think of substituting the vapid offerings of ID theorists for as vigorous a theory as Darwinism is absolutely unconscionable.
Until its concepts are defined with a precision beyond that bequeathed by ideas from natural theology and its arguments predicated on a firmer basis than dubious analogies with human intelligent agency, ID cannot be considered science. But if ID is not science is it creationism? I am willing to accept that there is a conceptual distinction between ‘creation’ and ‘design’ and so shall conclude that, we simply do not know whether or not ID is creationism since ID theorists refuse to elaborate on how the Intelligent Designer is supposed to go about his business, its agency having never been observed.
The extra- and intra-scientific importance of the question of ID’s scientific credentials
Whilst it may be that we should perhaps have started with another question than that of whether or not ID is science, the question is still important and worth consideration. Science, unquestionably one of the greatest achievements of our species, is invested with tremendous authority within modern western culture, and so the conferment of scientific status upon ID has numerous extra-scientific implications, particularly in the educational sphere. Larry Laudan has remarked that ‘the value-loaded character of the term “science” (and its cognates) in our culture should make us realize that the labeling of a certain activity as “scientific” or “unscientific” has social and political ramifications which go well beyond the taxonomic task of sorting beliefs into two piles.’ Even if determining whether ID is science is merely an exercise in intellectual taxonomy, it is an exercise with serious implications.
But it is not just the extra-scientific implications of the question which demand its consideration; the question has significant implications for science itself as the classification of ID as science would entail the dispensation of methodological naturalism which is one of the defining characteristics of modern science. The inference which ID makes from natural effects to a supernatural cause is at variance with modern scientific practice. As Sarkar writes, ‘naturalism is central to the pursuit of science.’ He concedes that ‘it is legitimate to argue that science may change to embrace strategies beyond methodological naturalism [the view that science is neutral regarding the existence of supernatural entities and that scientific explanations should be naturalistic] but that will require changes as drastic as the conceptual revolutions [of Newtonian mechanics, general relativity, quantum mechanics and natural selection]’. I would argue that the relinquishment of methodological naturalism would require changes of a different order to those precipitated by these conceptual revolutions, for, and as Sarkar notes, all of these conceptual revolutions have accorded with methodological naturalism. The development of science has seen the gradual displacement of supernaturalistic explanations by naturalistic explanations. Whilst supernaturalistic explanations were once permitted within science, they now no longer are. Philip Kitcher refers to intelligent design as ‘dead science’, ‘a doctrine that once had its day in scientific inquiry and discussion, but that has rightly been discarded.’ It is also worth noting that when intelligent design was a living science it was explicitly theistic. ID seeks to revivify its inhumed carcass and yet remove the theistic flesh which legitimised it.
Why the intelligent designer must be a supernatural being
Many ID theorists, Joshua included, are theists of a Christian variety who identify the intelligent designer as God—that is, these theists believe that the cause of designed structures is supernatural. However, ID theorists maintain that, whilst this may be, the Designer need not be supernatural. Behe has said that ID theorists ‘simply focus on the observation of design’ and that ‘the identity of the designer will be ignored by science.’ It is therefore held that the Designer could be a natural entity, an alien of some kind, thereby allowing ID theorists to deny its inconsistency with methodological naturalism. However, whilst this may be, one is then confronted with the question, whence the natural Designer: either the natural Designer evolved (most plausibly by some Darwinian process) or was the product of design or some combination of the two. As the designer of ICSs, the natural Designer would, being significantly more complex than its products, also contain at least one ICS which, according to ID, cannot evolve and so must be the product of design. This being so, and since there can be no infinite regress of natural designers due to the finiteness of the universe, the Designer must be supernatural. If it is necessarily the case, then, that the intelligent cause inferred by ID theorists is supernatural, ID is inconsistent with methodological naturalism. If methodological naturalism is essential to science, then ID cannot be considered science.
The inconsistency of ID with methodological naturalism
Dembski admits that ‘So long as methodological naturalism sets the ground rules for how the game of science is to be played, intelligent design has no chance of success.’ His solution: ‘dump methodological naturalism.’ He contends that ‘design should be readmitted to full scientific status.’ Yet the fulfilment of this solicitation would amount to the rejection of modern science and the palingenesis of ‘dead science’. Some ID proponents complain that the inclusion of naturalism within a definition of science is arbitrary. One should, however, distinguish between descriptive and stipulative definitions. The statement that ‘naturalism is central to the pursuit of science’ is not an arbitrary stipulation but a description of modern science. Of course, the fact that naturalism is central to the pursuit of science does not mean that it should be. As Stephen Meyer rightly says, ‘The indicative does not, after all, imply the imperative.’ Nevertheless, there is a normative justification for the scientist’s commitment to methodological naturalism, namely, that doing so has been immensely fruitful. As Ruse exclaims, ‘Methodological naturalism works!’ As long as design (or some form of supernaturalistic causation) is a real possibility staunch commitment to methodological naturalism may prevent us from accessing the truth. For this reason, methodological naturalism must be a revocable doctrine, yet its past success and the failure of ID theorists to offer convincing evidence of design give no reason to think its revocation due.
Unlike Ruse and others, I shall not argue that because ID is inconsistent with methodological naturalism it is therefore unscientific since it is conceivable that one day this principle of methodology, even though it has carried us so far, may have to be abandoned and design become the subject of scientific inquiry. However, ID’s inconsistency with naturalism places it at variance with the rest of science and this fact gives us a reason to deny that ID is scientific.
Testing ID against Darwinism
Joshua has asserted that ID is testable, however, since ID theorists do not identify the designer, we lack information about the goals and abilities of the designer which is required to test the design hypothesis. As I said above, I shall assume that the design hypothesis is intelligible since I think that it is to an extent, but only insofar as we are prepared to rely on dubious analogies and our inheritance from the natural theological tradition. According to Sober, testing a hypothesis (i) involves probabilistic (rather than strictly deductive) relations to observations and (ii) is contrastive. According with the Duhem-Quine thesis, Sober writes that ‘testable theories typically do not make predictions (whether deductive or probabilistic) all by themselves but need to make use of additional auxiliary propositions.’ As Fitelson et al. write, ‘To test evolutionary theory against the hypothesis of intelligent design, you must know what both hypotheses predict about observables.’ In asking what predictions the hypotheses of ID and Darwinism make we are asking what observations we would expect to make given the truth of each of the hypotheses. In order to test the hypothesis (say) that the bacterial flagellum was intelligently designed against the hypothesis that it evolved by a Darwinian process we require auxiliary assumptions about the goals and abilities of the designer for which there must be ‘independent reason’. We cannot simply cook up these auxiliary propositions; rather, we must acquire them by identifying ‘auxiliary information that is independently supported.’ ID proponents often present a design inference as an inference to the best explanation, where which of the competing candidate explanations is to be inferred is decided by a likelihood analysis. ID theorists claim that the existence of structures such as the bacterial flagellum which are ICSs or exhibit high amounts of CSI are highly improbable given Darwinism but far more probable given ID. Expressed symbolically,
Pr(bacterial flagellum | ID) >> Pr(bacterial flagellum | Darwinism).
Note that the ID theorist need not claim that the likelihood (the probability which a hypothesis confers upon an observation) of ID is far greater than the likelihood of Darwinism, as we should favour ID even if its likelihood is only slightly greater than the likelihood of Darwinism—that is,
Pr(bacterial flagellum | ID) > Pr(bacterial flagellum | Darwinism)—,
nor that ID confers an absolutely high likelihood upon the bacterial flagellum. It may be that Pr(bacterial flagellum | ID) is very low, but as long as it is higher than Pr(bacterial flagellum | Darwinism) ID should be favoured. However, without auxiliary assumptions about the goals and abilities of the Designer—Is the Designer concerned with the locomotive capabilities of bacteria? Is it within his power to furnish bacteria with flagella?—we have no way of knowing whether the above comparisons are correct since we have no idea what Pr(bacterial flagellum | ID) is.
Lydia McGrew appreciates that information about the goals and abilities of the designer is ‘difficult to obtain’, but she claims that it is ‘unnecessary’ for assessing the likelihood of ID, her reason being that we regularly and unproblematically infer intelligent causation even when we have no knowledge of the identity of the putative agents and so no knowledge of their goals and abilities. For instance, when we discover an arrowhead with serrated edges or a death which is obviously not a suicide or due to natural causes we infer an intelligent cause. McGrew argues that from our empirical knowledge of intelligent (human) agents producing ICSs we can induce that biological ICSs were also produced by an intelligent (though non-human) agent of whom we have no empirical knowledge. Since we (correctly) infer intelligent causes of certain effects with certain properties, when confronted with certain other effects which share some of the properties of those intelligently-caused effects we can infer that those effects whose origins are under investigation were also intelligently caused. We do not know, however, if such an argument from analogy is sound, for effects which share similar properties can be due to different causes. For instance, greyhounds and cheetahs share similar properties, swiftness being one example. However, greyhounds and cheetahs are not swift for the same reasons. The swiftness of greyhounds is due to a form of ID (selective breeding), but it would be a mistake to infer from this fact that the swiftness of cheetahs is also due to ID. Whilst McGrew claims that knowledge of the goals and abilities of the designer is ‘unnecessary’, it is by appealing to the goals and abilities of putative designers that we are able to determine that the causes of swiftness in greyhounds and cheetahs are different: human agents sought to breed swift greyhounds for racing and were able to do so by carrying out selective breeding programmes, whereas there were no humans around when cheetahs became swift and even if there were it is unlikely that they would have been able or wanted to make cheetahs swift. The fact that a biological system such as the irreducibly complex flagellum is similar to irreducibly complex artefacts designed by humans does not offer an indication of the likelihood of ID as we don’t know what the (non-human, supernatural) designer wants to produce or what he is capable of producing since we have no empirical knowledge of the designer. Contra McGrew, it cannot simply be assumed that a putative designer would be like human designers. As long as we do not know what the intelligent designer would make, we cannot test the hypothesis that a biological system was intelligently designed. At some future time we may acquire the requisite auxiliary information which would enable us to answer questions about the goals and abilities of the designer and determine the likelihood of ID. Until then, however, these questions must go unanswered. Until they are answered ID cannot be tested against Darwinism. It must be noted, however, that this does not mean that ID must always remain untestable, as that would require ‘considerable knowledge about what the future of inquiry may bring.’
Despite the allure testability has held for demarcationists, it cannot provide a successful demarcating criterion. If it were adjudged that a theory which currently cannot be tested cannot be science because it is untestable, then had such adjudications been made in the past many successful scientific theories would have been rejected in their inchoate stages as unscientific since it is unlikely that the rudimentary formulations of scientific theories will yield testable predictions.
The real problem with ID
I have tried to show that attempts to dismiss ID by claiming that it is not science through the deployment of demarcation criteria are unsuccessful. Not only are they unsuccessful, they create a smokescreen of philosophical controversy behind which the real problem with ID remains hidden.
Sarkar writes that ‘to be science, a doctrine must make substantive claims though making such claims does not by itself confer scientific status.’ Sarkar notes that ‘Making substantive claims is not a demarcation criterion,’ but rather ‘an adequacy test for a science’—a test which ID ‘fails’. Whilst the ID literature is saturated with negative argumentation there is a striking paucity of positive argumentation. The positive theory of ID boils down to the unilluminating claim that certain structures are the result of intelligent causation. As Sarkar notes, ‘if we add the claim that the designer is a conscious physical entity, the natural reaction should be to regard ID as coherent but with no evidence whatsoever to support it and all evidence against.’ However, given that the designer must be a supernatural entity, as I have argued, ‘we no longer have any clue what “intelligence” means.’ ID is not science because we are unable to make sense of the smidgeon of positive theory which ID proponents do offer without relying upon dubious analogies and ideas inherited from the natural theological tradition.
Sarkar willingly concedes that ID may have a future, given the possibility that the concept of design may be precisely specified and empirically anchored, but that ‘at present ID is not yet science simply because we have no such (substantive, rather than metaphorical) theory of ID that is comprehensible without implicit appeal to prior acquaintance with Christian theology and the metaphorical invocation of its fundamental concepts of intelligence and design.’ ID is not science, not because it fails to satisfy any demarcation criterion, but simply because it does not make substantive claims. The real problem with ID is its vapidity.
Creation and design
I have argued that ID is not science—but is it creationism? Both ID and creationism share significant commonalities: both ideas invoke supernatural causation, claiming that we can infer supernatural causes from natural effects and that certain aspects of the world cannot be explained in terms of natural processes. Unlike creationism, ID is not based on religious doctrine. Earlier, I used (1) to argue that ID is some form of creationism. I am willing to accept, however, following Dembski, that there is a conceptual distinction between ‘creation’ and ‘design’: creation involves bringing material into being whereas design involves merely rearranging pre-existing materials. According to the logic of my earlier argument I cannot now claim that ID is creationism. However, since ID theorists have failed to elaborate on how the designer brings about his designs, we should conclude that we simply do not know whether ID is creationism or not, although some day we may.
In conclusion, ID is not science. Despite the similarities between ID and creationism, we do not know whether ID is (some form of) creationism or not. Despite the outlandish claims its proponents perpetuate on its behalf, ID does not offer any insights (great or otherwise) into the origins of the living world. By contrast, Darwinism is a theory of immense explanatory power, accounting for a swathe of facts which otherwise remain disparate and unconnected. Darwin showed that the appearance of design in the living world is illusory, or, alternatively—although it amounts to the same thing—that the design in the living world does not require a designer. I think that ‘design-talk’ is permissible within biology—that one could say that the biosphere contains designed elements—but, if so, it should be made quite clear that this design does not imply an intelligent designer: if the living world exhibits design, then it must be there are non-intelligent design processes as well as intelligent design processes. With his discovery of natural selection Darwin performed an ‘exorcism against Paley’, demonstrating that design can result from a non-intelligent process which has ‘no vision, no foresight, no sight at all.’ Whatever the similarities between human artefacts and biological systems, their causes are quite dissimilar.
I realise that I have said rather a lot and so shall not expect Joshua to respond to each point that I have raised. I hope that I have been clear and I look forward to Joshua’s response. I am excited to be continuing with this fascinating and important conversation.
 David Hume, Dialogues concerning natural religion, in: Principal writings on religion including Dialogues concerning natural religion and The natural history of religion, edited with an introduction and notes by J. C. A. Gaskin, (Oxford: Oxford University Press, 2008), p.30.
 Joshua Gidney, Third response, ‘Debating Darwin and design: science or creationism? (7)’, available at: http://www.uncommondescent.com/intelligent-design/debating-darwin-and-design-science-or-creationism-7-joshua-gidneys-third-response/.
 Sahotra Sarkar, ‘The science question in intelligent design’, Synthese, 178, p.291-305, (2011), p.293.
 Ibid., p.304.
 Ibid., p.303.
 It could be argued that since so many thinkers and practitioners have contributed to the expansive field of evolutionary theory it would be unjust to affix to it the label of ‘Darwinism’. Whilst I can sympathise with such a sentiment, I would respond that evolutionary theory is so indebted to Darwin given the scope of his work and his astonishing prescience—just read the Origin!—that, in no way denying or downplaying the contributions of others, one can justifiably refer to evolutionary theory as ‘Darwinism’ simply because it is so manifestly the development of Darwin’s theory.
 The classic statement of the argument from design was given by Archdeacon Reverend William Paley in his Natural theology; or, evidence of the existence and attributes of the Deity, (London: Faulkner, 1802). Paley argued that adaptations such as the eye, composed of numerous parts which interact to perform a function, are so exquisitely structured that they are unmistakably the handiwork of a benevolent God. ID makes no such explicitly theological claims, however there is an obvious filial relation between the two ideas. Michael Behe’s arguments about the irreducible complexity of certain biomolecular structures, such as the bacterial flagellum, bear an obvious semblance the arguments of Paley.
 William Dembski writes that biochemistry provides ‘the causal backdrop against which design in biology must be decided’ (Intelligent design: the bridge between science & theology, [Downers Grove, IL: InterVarsity Press, 1999], p.14).
 Larry Laudan, ‘The demise of the demarcation problem’, in: Physics, philosophy and psychoanalysis, p.111-27, edited by R. S. Cohen and Larry Laudan, (Dordrecht: Reidel, 1983), reprinted in: But is it science?: the philosophical question in the creation-evolution controversy, p.337-350, edited by Michael Ruse, (Amherst, NY: Prometheus Books, 1996), p.345.
 But, then, perhaps we should simply ignore the question? Laudan has rightly observed that ‘demarcation criteria are typically used as machines de geurre in a polemical battle between rival camps,’ opining that ‘If we would stand up and be counted on the side of reason, we ought to drop terms like “pseudo-science” and “unscientific”… [since] they are just hollow phrases which do only emotive work for us,’ insisting that ‘our focus should be squarely on the empirical and conceptual credentials for claims about the world’ (ibid., p.349). I agree with the spirit of Laudan’s remarks but I would not go so far as to pronounce matters of nomenclature ‘irrelevant,’ (ibid.) as, whilst not always clear, there are differences in patterns and standards of reasoning in different modes of inquiry which should be respected.
 Sahotra Sarkar, Doubting Darwin: creationist designs on evolution, (Malden, MA/Oxford: Blackwell), p.163.
 Philip Kitcher, Living with Darwin: evolution, design, and the future of faith, (New York, NY: Oxford University Press, 2007), p.8. Kitcher accepts that ‘If intelligent design is no longer science, it once was, and many scientific achievements we acknowledge build upon work that it inspired’ (p.12).
 It should be noted that there are ID proponents who are not theists and who do not believe the intelligent designer to be a supernatural being.
 Michael Behe, in conversation with John Sutherland, ‘A design for life’, Guardian, 12 September, (2005), available at: http://www.guardian.co.uk/science/2005/sep/12/religion.news>.
 Michael Behe, Darwin’s black box: the biochemical challenge to evolution, (New York: Touchstone, 1998), p.251.
 Richard Dawkins has argued that Darwinism is probably a universal principle in his paper ‘Universal Darwinism’, in: D. S. Bendall (ed.), Evolution from molecules to men, p.403-25, (Cambridge: Cambridge University Press). I am inclined to agree with him.
 I presented a version of this argument in an earlier response to Joshua (Second response, ‘Debating Darwin and design: science or creationism (1)’, fn.23., available at http://musingsofscience.wordpress.com/2011/11/02/debating-darwin-and-design-science-or-creationism-4-2/). Elliott Sober had already presented an argument similar to mine which reaches the same conclusion—that the Intelligent Designer must be supernatural—although unbeknownst to me as I had not then read his paper ‘Intelligent Design theory and the supernatural—the “God or extra-terrestrials” reply’, Faith and Philosophy, 24 (1): 72-82, (2007), available at: http://sober.philosophy.wisc.edu/selected-papers. Sober argues that we have reason to believe, independent of the veracity of ID, that minds in nature are irreducibly complex, that the universe is finitely old and that causes precede their effects. Given these propositions, if minds in nature are irreducibly complex then they must be the product of intelligent design, but since the universe is finitely old and causes precede their effects there cannot be an infinite regress of natural designers and so the Intelligent Designer must be supernatural. Sober also concludes that Darwinism is neutral on the question of the existence of supernatural entities.
 Dembski, Intelligent design, p.119.
 Ibid., p.123.
 In defence of his claim that science is ‘an enterprise formed through the practice of methodological naturalism’, Michael Ruse writes, ‘What I am trying to do is to offer a lexical definition: that is to say, I am trying to characterize the use of the term “science.” And my suggestion is simply that what we mean by the word “science” in general usage is something that does not make reference to God and so forth, but which is marked by methodological naturalism’ (‘Methodological naturalism under attack’, in: Intelligent design creationism and its critics, p.363-85, edited by Robert T. Pennock, [Cambridge, MA/London: The MIT Press, 2001], p.371).
 Stephen Meyer, ‘The methodological equivalence of design & descent: can there be a scientific “theory of creation”?’, in: J. P. Moreland (ed.), The creation hypothesis: scientific evidence for an intelligent designer, chap.2, p.67-112, (Downers Grove, IL: InterVarsity Press, 1994).
 Michael Ruse, Darwinism and its discontents, (Cambridge: Cambridge University Press, 2008), p.48.
 As Del Ratszch writes, ‘if it should turn out that some things in nature are deliberately designed and can only be correctly understood in design terms, then a human edict that deliberate design is a scientifically forbidden concept will inevitably drive our scientific investigation, in that area, into either error or failure’ (‘There is a place for intelligent design in the philosophy of biology: intelligent design in (philosophy of) biology: some legitimate roles’, in: Contemporary debates in philosophy of biology, chap.19, edited by Francisco J. Ayala and Robert Arp, [Chichester: Wiley-Blackwell, 2010], p.346-7).
 Joshua Gidney, ‘Debating Darwin and Design: science or creationism? (1)’ Opening, available at: http://www.uncommondescent.com/philosophy/debating-darwin-and-design-science-or-creationism-1/.
 Elliott Sober, Evidence and evolution: the logic behind the theory, (Cambridge: Cambridge University Press, 2008), p.152.
 The Duhem-Quine thesis derives its name from the French physicist and philosopher of science Pierre Duhem and the American philosopher W.V.O. Quine. According to the thesis, scientific hypotheses do not make predictions independently; rather, auxiliary hypotheses are required in order for test implications to be derived from a theory.
 Elliott Sober, Evidence and evolution: the logic behind the theory, (Cambridge: Cambridge University Press, 2008), p.148. This point was also made by Carl Hempel in his classic work Philosophy of natural science, (Englewood Cliffs, NJ: Prentice-Hall, Inc., 1966), p.31.
 Branden Fitelson, Christopher Stephens and Elliott Sober, ‘How not to detect design—critical notice: William A. Dembski, The design inference’, in: Intelligent design creationism and its critics, p.597-615, p.613.
 Sober writes that ‘testing a proposition often involves probabilistic rather than deductive relations to observations and that the concept of testing needs to be understood contrastively’ (Evidence and evolution, p.152). According to Sober,
Hypothesis H1 can now be tested against hypothesis H2 if and only if there exist true auxiliary assumptions A and an observation statement O such that (i) Pr(H1|O&A) ≠ Pr(H2|O&A) (ii) we now are justified in believing A, and (iii) the justification we have for believing A does not depend on believing that H1 is true or that H2 is true and also does not depend on believing that O is true (or that it is false). (ibid.)
 Ibid., p.144.
 Ibid., p.168.
 Peter Lipton in his seminal book Inference to the best explanation (second edition, [London: Routledge, 2004]) presented a lucid and perspicacious elaboration of the inferential procedure.
 As Sober says, ‘don’t ask whether the hypothesis says that the outcome was probable or improbable. The relevant question is whether the outcome is more probable according to one hypothesis than it is according to another’ (‘Testability’, p.57).
 We do not need to know the precise probabilistic values for each of the likelihoods; we only need to know how the probabilities compare (cf. Sober, ‘Testability’, p.58). But since we have no idea what Pr(bacterial flagellum | ID) could be, we do not know how the likelihoods compare.
 Incidentally, the mousetrap is not an example of an ICS, as has been pointed out in many criticisms of Behe’s discussions of irreducible complexity.
 This example is due to Daniel Dennett (cf. Darwin’s dangerous idea: evolution and the meanings of life, [London: Penguin Books, 1996], p.318) and is also discussed by Sober (cf. ‘Testability, p.63-4).
 McGrew writes that ‘It is arbitrary to require special hesitation in applying data from a known group to an unknown group in biological arguments for design… Perhaps we have reason to believe that [the intelligent designer] would be more powerful or more intelligent than humans, would possess a different kind of body from humans, or might even be disembodied. [If my argument that the intelligent designer must be supernatural is sound, then we can suppose that the designer is disembodied.] But even granting the probability of such differences, it does not follow that such an agent would differ from humans in inclination or ability to make machines’ (‘Testability, likelihoods and design’, my italics). Whilst it does not follow than the intelligent designer would differ from humans in inclination or ability to make machines, we cannot suppose that it does not.
 Cf. Sober, ‘Testability’, p.64.
 Sober, Evidence and evolution, p.149.
 Sarkar, ‘The science question in intelligent design’, p.293.
 Ibid., p.303.
 Sarkar writes that ‘because we have the intuitively reasonable idea that design means conforming to a target, we can imagine that the concept of CSI can eventually be characterized sufficiently precisely, perhaps even operationalized, and connected to the empirical world. We should not forget that the development of many sciences followed this pattern of gradual clarification of concepts over time’ (‘The science question in intelligent design’, p.301).
 Ibid., p.302.
 It is worth noting however that Stephen Meyer does not seem to think that there is a conceptual distinction as he treats the terms ‘design’ and ‘creation’ synonymously (cf. ‘Is intelligent design science?’).
 Dembski writes that ‘Creation is always about the source of being of the world. Intelligent design, as the science that studies signs of intelligence, is about arrangements of preexisting materials that point to a designing intelligence. Creation and intelligent design are therefore quite different. One can have creation without intelligent design and intelligent design without creation’ (‘Intelligent design’, available at: http://www.designinference.com/documents/2003.08.Encyc_of_Relig.htm).
 Richard Dawkins coined the term ‘designoid’ (pronounced ‘design-oid’) to designate structures which ‘look designed, so much so that some people—probably, alas, most people—think that they are designed’ (Climbing Mount Improbable, [London: Penguin Books, 2006], p.4).
 Cf. Francisco J. Ayala, ‘Darwin’s greatest discovery: design without a designer’, Proceedings of the National Academy of Science of the United States of America, 104, p.8567-73, (2007).
 Daniel Dennett has argued strenuously for the retention of ‘design-talk’ within biology (cf. Darwin’s dangerous idea, [London: Penguin Books, 1996]).
 Simon Conway Morris, ‘(Re) Reading the Origin’, Current Biology, 19 (3), R103, (2009).
 Richard Dawkins, The blind watchmaker, (London: Penguin Books, 1988), p.5.