Genuine Science versus Dembskis ZFactors

Regarding the question of whether intelligent design is genuine science or pseudoscience, it also seems relevant to review the concept that Dembski

(2002b) calls Z-factors. He defines these as "some entity, process or stuff outside the known universe [which] . . . purports to solve some problem of general interest and importance" (87). Dembski defines the inflationary fallacy as estimating the probability of an event based not only on reliable knowledge but also on an arbitrary additional hypothesis, which he calls a Z-factor. A Z-factor is an unjustified excursion beyond the available knowledge (in Dembski's terms inflation of probabilistic resources), which can be used to estimate the probability of an event.

Dembski discusses four Z-factors: the bubble universes of Alan Guth's (1997) inflationary cosmology, the many worlds of Hugh Everett's (1957) interpretation of quantum mechanics, the self-reproducing black holes of Lee Smolin's (1997) cosmological natural selection, and the possible worlds of David Lewis's (1986) extreme modal realist metaphysics. These four concepts postulate the existence of many (so far undetected) universes besides our own. They offer different assumptions regarding the origin of the multiple universes and their putative properties. None has a direct empirical basis, but their authors have proposed arguments in favor of their plausibility, and each of these hypotheses has a certain explanatory potential regarding the structure and the history of our universe.

The available knowledge about the structure and history of the universe is insufficient to choose among the hypotheses by Guth, Smolin, Everett, and Lewis. Dembski therefore calls all four concepts Z-factors. The four Z-factors in question are indeed speculative, but that is not the issue in this chapter. We are, rather, interested in some of the arguments Dembski suggests against the inflationary fallacy.

In Dembski's (2002b) view, "Each of the four Z-factors considered here possesses explanatory power in the sense that each explains certain relevant data and thereby solves some problem of general interest and importance" (90). He continues, however, to say that possessing explanatory power is not sufficient for accepting a theory. What is also necessary is independent evidence in favor of that theory: "Independent evidence is by definition evidence that helps establish a claim apart from any appeal to the claim's explanatory power. . . . It is a necessary constraint on theory construction so that theory construction does not degenerate into total free-play of the mind" (90).

As an example, Dembski discusses a hypothetical gnome theory of friction: "suitably formulated, the gnome theory of friction can explain how objects move across surfaces just as accurately as current physical theories. So, why do we not take the gnome theory of friction seriously? One reason ... is the absence of independent evidence for gnomes" (91).

Even if we disregard Dembski's dubious assertion that the gnome theory can explain friction as well as current physical theories, we can agree with him that a plausible theory has to offer explanatory power (otherwise, it is not useful) and be supported by independent evidence (otherwise, it would "degenerate into total free-play of the mind" [90]). Do intelligent-design theories—in particular, Dembski's—provide explanatory power? Are they supported by independent evidence? We suggest that the answers are unequivocally no.

ID theory claims that we can establish design by some rational procedure, whose principal features are encapsulated in Dembski's explanatory filter. Detailed analyses of the explanatory filter may be found in chapter 8 of this book and elsewhere (Chiprout 2003; Elsberry 1999, 2000; Fitelson et al. 1999; Perakh 2001b, 2002a, 2003; Wilkins and Elsberry 2001; Elsberry and Shallit 2002). Here, we are interested only in answering the questions about explanatory power and independent evidence.

Does intelligent-design theory provide explanatory power? If so, it must provide information about the details of the design and, to this end, about the nature of the designer. ID theory, however, deliberately avoids the answers to this question. Advocates of intelligent design (Dembski 1999) insist that their theory is not tied to any concept of a designer but just provides a means to distinguish among chance, regularity, and design as the causal antecedents of the event in question.

The designer in the intelligent-design theory looks like another Z-factor. Indeed, Dembski's concept is based on a much more egregious inflationary fallacy than those of his four offenders. Guth (1997) and Smolin (1997) at least suggest ideas in regard to the features, properties, and behavior of their Z-fac-tors. By contrast, Dembski deliberately leaves beyond consideration the attributes of the Z-factor in his own theory. Moreover, Guth and Smolin have suggested certain ideas for indirect tests of their Z-factors, while the advocates of intelligent design propose nothing even close to an empirical test.

In fact, the intelligent-design theory does not have explanatory power. To simply state that an event is due to intelligent design explains nothing because the term designer has no defined meaning in the theory and the modes of the designer's activities remain mysterious and unexplained. Indeed, both Behe (1996) and Dembski (1998a, 2002b) refuse to even speculate on the attributes of the designer, whose existence can supposedly be asserted using the design inference (Dembski 1998a, 1999, 2002b). Hence, while Dembski has stated the necessity of explanatory power for any useful theory, he forgets about that requirement when turning to his own theory.

Advocates of intelligent design usually refuse to discuss the nature of the alleged designer. They try to deflect criticism of their refusal by citing examples in which design is inferred despite the lack of knowledge about the designer. For example, Dembski asks, Is the design inference legitimate in the case of Stonehenge? We all agree that it is. He says, however, that nothing is known about the designer in that case either. On the contrary, as regards Stonehenge and similar cases, we infer a well-known type of a designer: a human designer. We attribute the creation of Stonehenge to a human designer precisely because we know so much about the features of human design and see those features in the object observed.

In another example, Dembski (2002b) refers to a book by Del Ratzsch (2001). Ratzsch suggests imagining that an expedition to some planet of the solar system finds a bulldozer standing in a field. Obviously, we conclude that the bulldozer was designed rather than that it happened to exist by sheer chance. Dembski insists, however, that we infer a designer without any knowledge about the designer and his characteristics. Why cannot the same attitude be applied to a mysterious designer in his design theory?

The fallacy of such an argument is evident. A bulldozer on an alien planet has features that testify not only to certain characteristics of its supposed designer but also to the possible use for which it was designed. The bulldozer has treads evidently designed for motion, a seat evidently designed to accommodate a creature anatomically similar to earthly humans, pedals evidently designed for feet similar to those of earthly humans, and many other features providing good ideas about what kind of a designer must be responsible for the observed object and what use it was intended for. Additionally, we have prior experience of bulldozers and know that they are artifacts.

In Ratzsch's terms, a bulldozer displays an obvious artifactuality. In Niall Shanks and Karl Joplin's (1999) terms, the bulldozer is "antecedently recognizable as an artifact" (269). It is precisely because we know so much about both bulldozers and the humans who design them that we would infer design if a bulldozer were found on Mars. Moreover, the design inference in the case of that bulldozer will be made without any reference to Dembski's explanatory filter, which is utterly useless for inferring design in the hypothetical case under discussion.

The bulldozer example is irrelevant for many other reasons as well. A bulldozer is not a living organism that can reproduce, develop, or evolve spontaneously. Indeed, the design inference is controversial only with respect to biological entities. When we see a bulldozer or a poem, there is no controversy; we unequivocally attribute them to design because of our extensive knowledge about such objects and the human designers who create them. In contrast to bulldozers and poems, organisms are not designed but inherit genes from their forebears. A bulldozer is designed by an engineer and built by la borers according to the engineer's design. Dembski and his colleagues seem peculiarly blind to the obvious difference between artifacts and organisms.

We know nothing whatsoever about the alleged disembodied designer of the intelligent-design theory or about what that designer's creations should look like. The case is therefore very different from bulldozers and poems. A reference to such a designer lacks explanatory power.

According to Dembski, an even more important requirement for a theory is independent evidence supporting that theory. Strangely, he and his colleagues in the intelligent-design enterprise forget about the criterion of independent evidence as soon as they turn to their own theories. Where is independent evidence supporting the intelligent-design theory? There is none. The absence of explanatory power and of independent evidence, according to Dembski's own criteria, signifies the degeneration of the theory into a "total free-play of the mind," which Dembski seems to disapprove of for all theories except his own. Despite their substantial financial resources, the advocates of intelligent design have so far failed to come up with a real scientific research program and indulge instead in philosophical or theological discourses and political maneuvering (Forrest 2001).

Dembski views explanatory power as a category independent of evidence. Indeed, the gnome theory of friction, in his view, can provide explanatory power despite lack of evidence for the existence of gnomes. Explanatory power without evidence is, however, meaningless. The gnome theory of friction does not plausibly explain friction precisely because there is no evidence of the gnomes' existence. The gnome theory is pure speculation and has no explanatory power. Explanatory power is meaningful only if it is based on facts and evidence. To say that friction is caused by gnomes is to explain nothing because we have no knowledge about what kind of a behavior those postulated gnomes may have. In fact, a theory has plausible explanatory power only if it is also supported by evidence.

Dembski's intelligent designer is just another Z-factor. His separation of explanatory power from evidence is contrived; it is no more than the "freeplay of the mind," a mote that he finds in the eyes of others.

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