Thursday, April 20, 2006


Sagan's Implicit Endorsement of Specified Complexity as a Design Detector

In The Demon Haunted World Carl Sagan debunks a number of claims about purported instances of design. For example:

'There was a celebrated eggplant that closely resembled Richard M. Nixon. What shall we deduce from this fact? Divine or extraterrestrial intervention? Republican meddling in eggplant genetics? No. We recognize that there are large numbers of eggplants in the world and that, given enough of them, sooner or later we'll come upon one that looks like a human face, even a very particular human face.' (p. 47.)

Notice that the suggestion of design here is based upon the fact that the eggplant in question exhibits a specification - an independently given pattern. In this case, the specification is looking like a human face, and more than that, looking like a particular human face (Nixon - although it is hard to believe that the resemblance can have been all that tight). That the eggplant exhibits this specification is implicitly accepted by Sagan. So why does Sagan reject the idea that the correspondence between the eggplant and the Nixon specification is the result of design? Because the example lacks complexity. Given the number of human faces and eggplants that have existed Sagan argues that it is not all that unlikely that we'd come accross an eggplant that bore a resemblance to a human face, even to Nixons. Hence we don't have to deduce divine, or extraterrestrial, or Republican design from the eggplant. Note that Sagan's argument for rejecting a design inference from the eggplant implicitly accepts that if the eggplant exhibited a specification at a sufficient level of complexity then a design inference would be justified. In other words, Sagan recognized that a design inference is warranted when faced with an example of 'complex specified information' or 'specified complexity'. This is why, in order to debunk a proposed instance of design which he admits exhibits specification, Sagan argues that the proposed example lacks sufficient complexity.

Note also that Sagan implicitly endorses the point made by many ID theorists that while specified complexity warrants an inference to 'intelligent design', it does not in and of itself warrant an inference to any particular designer: 'Divine or extraterrestrial intervention? Republican meddling in eggplant genetics?' All three explanations would be possible candidates if a design inference in this case were justified.

Sagan goes on to discuss the infamous so-called 'face on Mars', first photographed by one of the Viking orbiters in 1976. Sagan argues against a design inference in this instance as well. How does he do it? By arguing that the 'face' is neither very complex nor tightly specified. First he examines the complexity of the 'face':

'Mars has a surface area of almost 150 million square kilometers. Is it so astonishing that one (comparatively) postage-stamp-sized patch in 150 million should look artificial - especially given our penchant, since infancy, for finding faces?' (p. 56.)

In other words, it is not all that unlikely that a small area of Mars should look sufficiently like a face to make it appear face-like to casual observation. Then he goes after specification:

'If we study the original image more carefully, we find that a strategically placed 'nostril' - one that adds much to the impression of a face - is in fact a black dot corresponding to lost data in the radio transmission from Mars to Earth. The best picture of the Face shows one side lit by the Sun, the other in deep shadow. Using the original digital data, we can severely enhance the contrast in the shadows. When we do, we find something rather unfacelike there. The Face is at best half a face... the Martian sphinx looks natural - not artificial, not a dead ringer for a human face.' (p. 56, my italics.)

In other words, while at first glance the 'face' seems to exhibit a specification, a closer look shows that it doesn't. In Richard Dawkin's terminology, the supposed face on Mars is 'designoid'; it gives a superficial impression of design at first glance, but the more we investigate its salient features, the less designed it looks. Hence Sagan concludes: 'It was probably sculpted by slow geological processes over millions of years.' (p. 56)

The important point here is that in order to justify this conclusion Sagan seeks to undermine precisely those twin features of things that design theorists recognize as jointly sufficient conditions for justifying a design inference: namely complexity and specification.

If Sagan is right to argue that the 'face' is not designed because it fails to exhibit specified complexity (indeed, because it is neither sufficiently complex nor tightly specified) then design theorists must be right to argue that anything which does exhibit specified complexity should be attributed to intelligent design.

For example, Sagan wouldn't argue that the presidential faces on Mount Rushmore were 'sculpted by slow geological processes', because unlike the Nixon eggplant and the 'face' on Mars, Mount Rushmore does exhibit specified complexity.

Although he doesn't use the terminology of 'specified complexity' Sagan implicitly endorses specified complexity as an adequate criterion of intelligent design, arguing that design inferences cannot be supported when the putative designed object lacks complexity or speficiation or both. This negative argument implies the positive argument that when a putative designed object exhibits specified complexity then a design inference is warranted.

Tuesday, April 18, 2006


Over Two Thousand Visits

Just a quick note to wish everyone a happy Easter and to celebrate my blog counter passing the two thousand visits mark (2024 to be precise)! The latest pie chart of visitors shows readers coming from 13 different countries, including the mysterious 17% from 'unknown country'. So if you live in 'unknown country', greeting to you!

Professor William Lane Craig is one of the top Christian scholars writing about the historical evidence for Jesus' resurrection. You can find his articles on the subject here :-)

Thursday, April 13, 2006


Carl Sagan's Positivist Hangover

Consider this statement from Carl Sagan's 'Baloney Detection' kit in The Demon Haunted World (1996):

'Always ask whether the hypothesis can be, at least in principle, falsified.
Propositions that are untestable, unfalsifable are not worth much.'
(p. 198.)

As a philosopher, I always ask whether a statement can be applied to itself without self-contradiction. In this case the answer is that while Sagan technically avoids self-contradicition, because he says that untestable propositions are 'not worth much' rather than that they are not worth anything, he is certainly skating on thin ice. His statement undermines itself. How, even in principle, could one empirically falsify the claim that unfalsifiable propositions are not worth much? You cannot. Hence, this part of Sagan's baloney detection kit is, by its own standards, 'not worth much'. How much epistemological worth is 'not much'? Isn't it a rather strange epistemology that elevates the epistemological worth of empirical observation over the epistemological worth of propostitions such as 'the law of non-contradiction is true' (which cannot be empirically verified)! Other empirically unfalsifiable statements that are surely 'worth something' are: 'The Holocaust was morally wrong' and 'Rainbows are beautiful'.

Wednesday, April 12, 2006


Do these quotes apply to Darwinism?

Some choice quotes from a well known writer on science:

'Spurious accounts that snare the gullible are readily available. Sceptical treatments are much harder to find. Scepticism does not sell well. A bright and curious person who relies entirely on popular culture to be informed about [] is hundreds or thousands of times more likely to come upon a fable treated uncritically than a sober and balanced assessment... all instances of pseudoscience... purport to use the methods and findings of science, while in fact they are faithless to its nature - often because they are based on insufficient evidence or because they ignore clues that point the other way. They ripple with gullibility. With the uninformed cooperation (and often the cynical connivance) of newspapers, magazines, book publishers, radio, television, movie producers and the like, such ideas are easily and widely available... Science thrives on erros, cutting them away one by one. False conclusions are drawn all the time, but they are drawn tentatively. Hypotheses are framed so they are capable of being disproved... Pseudoscience is just the opposite. Hypotheses are often framed precisely so they are invulnerable to any experiment that offers a prospect of disproof, so even in principle they cannot be invalidated. Practitioners are defensive and wary. Sceptical scruitny is opposed... Science invites us to let the facts in, even when they don't conform to our preconceptions. It counsels us to carry alternative hypotheses in our heads and see which best fits the facts. It urges us on a delicate balance between no-holds-barred openness to new ideas, however heretical, and the most rigorous sceptical scrutiny of everything - new ideas and established wisdom. This kind of thinking is also an essential tool for a democracy in an age of change... every time we excercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confusde hopes and facts, we slide into pseudoscience and superstition... There are no forbidden questions in science, no matters too sensitive or delicate to be probed, no sacred truths...'

If I told you that the author is criticizing the way in which the theory of evolution is treated by some in the scientific and so-called 'sceptical' communities, I would be lying, but I think I would be lying rather plausibly!

So, who is the author of this tirade against pseudoscience? Karl Popper perhaps? No. Phillip E. Johnson, author of 'Darwin on Trial'? Again, no. In actual fact, it is secular humanist Carl Sagan in his last book The Demon Haunted World (Headline, 1996).

Of course, to apply Sagan's words to Darwinism is to quote him totally out of context. Sagan assumes the truth of evolution. However, asking whether Sagan's words apply to Darwinism, at least as held in certain quarters, makes for an interesting exersize.

Readers may like to take particular note of the effects on the falsifiability of 'core darwinism' of adopting 'methodological naturalism' as a necessary condition of science. Other points of application spring to mind in relation to current debates about allowing even criticism of evolution to be considered by students in schools, let alone alternative hypotheses. And so on.

Thursday, April 06, 2006


More from Steve Fuller's 'Kuhn vs/ Popper'

'Popper's view that a non-scientist might criticise science for failing to abide by its own publicaly avowed standards is rarely found inside academia today. For those who have inhereted Kuhn's Cold War belief that normal science is a bulwark in a volitile world, it comes as no suprise that philosophers today sooner criticise Creationists for violating evolutionary strictures than evolutionists for violating more general scientific norms - an activity for which Popper had been notorious.' (p. 5-6.)

'Kuhnian normal science was a political primitve social formation that combined qualities of the Mafia, a royal dynesty and a religious order. It lacked the sort of constitutional safeguards that we take for granted in modern democracies that regularly force politicians to be accountable to more people than just themselves. Scientists should be always trying to falsify their theories, just as people should be always invited to find fault in their governments and consider alternatives - and not simply wait until the government can no longer hide its mistakes.' (p. 46.)

'For Popper, science is indeed in stasis -a "fallen" state, a closed society, much as the Roman Catholic Church was when Martin Luther launched what became the Protestant Reformation. This is the spirit in which we should understand Popper's most radical follower, Paul Feyerabend, who in the 1970s called for the devolution of state support for science to local authorities and supported the proliferation of such anti-establishment forms of inquiry as Creationism, Deep Ecology and New Age medicine. Feyerabend's attitude toward science was closer to a protestant's than an atheist's towards Christianity. Unfortunately, in our blinkerd times, to be against the scientific establishment is to be against science itself.' (p. 110.)

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