What does it mean to be "intelligently designed"?
Stated as succinctly as possible, the core scientific claim of the ID movement is, in effect: "We have firm empirical evidence that some biotic system X could not possibly have been actualized (at least not for the very first time) by purely natural processes; therefore X must have been intelligently designed." In order to evaluate that claim, two questions must be asked: (1) On what evidence and reasoning do ID advocates base their claim that X could not have been actualized by natural processes alone? (2) What does it mean to say that X was intelligently designed? Question (1) will be dealt with in our analysis of Dembski's claim that the bacterial flagellum (a specific example of an X) could not have formed naturally. Question (2) will now be the focus of our attention.
What do ID advocates actually mean when they say "X was intelligently designed"? Presuming that intelligent design is some form of action, what kind of action? And, action by what sort of agent?
We speak often today of things that have been designed. Cars are designed; clothing is designed; buildings are designed. Suppose, then, we were to walk into the headquarters of a major automobile manufacturer and ask to observe the process of cars being designed. What kind of activity would we be shown? Would we be taken to the assembly line to see cars being put together by human hands and mechanical robots? No, we would be taken to the "design center" where we would see people working with their minds (augmented, of course, by computers and various means of modeling what their minds conceive) to conceptualize new cars of various styles to achieve the intentions of the manufacturer in the marketplace. In other words, to say that a car was designed is to say that a car was thoughtfully conceptualized to accomplish some well-defined purpose. In contemporary parlance, the action of design is performed by a mind, intentionally conceptualizing something for the accomplishment of a purpose.
This mind-like action of designing is clearly distinguishable from the hand-like action of actualizing (assembling, arranging, constructing) what had first been designed. On a tour of an automobile manufacturing facility, for instance, we would have no difficulty in distinguishing the mental work done at the design center from the manual work done on the assembly line.
But in the history of thought about how living things got to be the way they now are, the word "design" as the name of an action has often had a different meaning. William Paley, an eighteenth century English clergyman, spoke eloquently of things like the eye as having been designed, much like he would say that a pocket-watch was designed. Clearly the several parts of a watch work efficiently and harmoniously to accomplish the task of keeping and displaying the time. Looking at a watch, we would say without hesitation that such a timepiece had been designed by a watchmaker. Without doubt, the watchmaker had used his mind to conceptualize the workings of the watch for the purpose of keeping and displaying the time.
But mind-action alone does not produce a working watch. The watch must also be actualized by hand-action. As an artisan, the watchmaker must not only conceptualize the configuration of gears and dials that comprise a watch; he must also form the various parts and assemble them into an actual working mechanism. In the context of eighteenth century natural theology, to say that something had been designed was to say that it had been both purposefully conceptualized (by mind-like action) and skillfully crafted (formed and/or assembled by hand-like action). This traditional meaning of design action was based on the artisan metaphor. One person, the artisan, performed two actions-mindfully conceptualizing some artifact and manually crafting what had first been planned.
What does it now mean to be "intelligently designed"? Given ID's almost exclusive emphasis on the question of how things came to be structured as they now are, and given ID's repeated emphasis on the presumed inadequacy of natural processes to actualize these structures, it is clear that the primary meaning of "X was intelligently designed" is that "X was actualized by the form-conferring action of some non-natural agent called an intelligent designer." As an action, intelligent design entails both the mind-action of conceptualization and the hand-like action of constructing or assembling some functional structure, with a very strong emphasis on "design" as the means of actualization. Adding the adjective "intelligent" sometimes functions (1) to call attention to the idea that design is an action of an intelligent (choice making) agent, with no claim made regarding the "optimality of design," and sometimes (2) to ensure "that the design we are talking about is not merely apparent but also actual."[23]
What sort of agents are capable of performing the proposed action of intelligent design? First, of course, they must be intelligent, which in this context means capable of making intentional choices. Human agents are certainly intelligent in this sense, but one could speak also of choice-making by some animals as well. However, as noted above, the intelligent agents of which ID speaks must also be able to effect what was first chosen, or to actualize what was first conceptualized.
When considering embodied intelligent agents, such as humans or animals, we have no difficulty envisioning how the dual action of conceptualizing and actualizing might be carried out. Paley's artisan-watchmaker could both conceive of an appropriate mechanical clockwork and then proceed to form the various parts and to assemble them into a functional watch. However, when ID advocates speak of biotic systems in nature as the products of intelligent design action they are proposing action by an agent of an entirely different sort-an umembodied intelligent agent who can both purposefully conceptualize something and actualize that conception in some material/physical structure. For the moment, suppose we set aside the matter of how an unembodied intelligent agent might engage in the mind-like action of conceptualizing something, say a bacterial flagellum. Philosophers and theologians have long presumed it reasonable to posit and reflect on such mind-like action.
The more difficult problem, it seems to me, arises when ID advocates posit an unembodied intelligent agent acting in such a way as to effect or modify some physical/material structure. How, for instance, might an unembodied intelligent agent act on a bacterium with no flagellum to actualize a flagellum where none had been before? How does intelligence (now meaning the action of an unembodied, choice-making agent) accomplish that? Does the unembodied agent somehow force the various atomic and molecular components into their proper configuration? How does a non-physical agent exert physical forces?
Dembski freely admits that he cannot offer any causally specific model for this action, but he also argues that this should not be seen as a shortcoming of the ID proposal. After all, "Intelligent design is not a mechanistic theory."[24] Yes, but earlier Dembski had suggested that a more substantial proposal regarding a model for designer action might be forthcoming. "A design inference therefore does not avoid the problem of how a designing intelligence might have produced an object: It simply makes it a separate problem."[25] It seems, however, that this particular "separate problem" has been permanently placed in the "solution impossible" file. Dembski's disclaimer that modeling intelligent design action is both unnecessary and at the same time a "separate problem" seems a bit thin.
But Dembski makes another disclaimer that seems even more difficult to maintain or defend: to posit intelligent design action is not the same as positing a miracle. In his effort to "get around the usual charge of miracles," as Dembski aptly puts it, he defines a miracle in a way designed to avoid the problem. "Miracles typically connote a violation or suspension or overriding of natural laws."[26] That is, where a natural cause was set to make X happen, Y happened instead.
According to Dembski, however, intelligent design action does not necessarily entail a suspension or overriding of natural laws.
When humans, for instance, act as [embodied] intelligent agents, there is no reason to think that any natural law is broken. Likewise, should an unembodied designer act to bring about a bacterial flagellum, there is no reason prima facie to suppose that this designer did not act consistently with natural laws. It is, for instance, a logical possibility that the design in the bacterial flagellum was front-loaded into the universe at the Big Bang and subsequently expressed itself in the course of natural history as a miniature outboard motor on the back of E. coli.[27]
What does Dembski here mean by "the design of the bacterial flagellum" that may have been "front-loaded into the universe at the Big Bang"? In the larger context of Dembski's argument, I am led to conclude that "design," used as a noun in this instance, here denotes both a plan and a provision-a plan for actualizing the flagellum and a provision of all of the initial conditions and formational capabilities needed to ensure that the plan would be carried out in detail. Front-loading a universe for the actualization of some biotic structure appears to be comparable to providing a computer with both a specific program and all of the computational capabilities needed to ensure that some particular result would be generated.
Elsewhere in No Free Lunch, however, Dembski makes it abundantly clear that he is no friend of this "front-loading" hypothesis. Dembski's Intelligent Designer is one who interacts with the universe in the course of time. The design action posited to actualize the bacterial flagellum, as we shall see, is an action that occurs long after the Big Bang. Furthermore, since Dembski argues vigorously that the assembling of E. coli's flagellum could not have come about naturally, the question is, 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?
Dembski does attempt an answer to this question. "The physical world consists of physical stuff, and for a designer to influence the arrangement of physical stuff seems to require that the designer intervene in, meddle with, or in some way coerce this physical stuff."[28] ... "But what if the designer is not in the business of moving particles but of imparting information? In that case nature moves its own particles, but an intelligence nonetheless guides the arrangement."[29] In response to concerns that I have often raised about the character of design as an action, Dembski says, "Van Till asks whether the design that design theorists claim to find in natural systems is strictly mind-like ... or also hand-like.... But Van Till has omitted a third option, namely, that design can also be word-like (i.e., imparting information to a receptive medium)."[30] So, as we try to picture an unembodied intelligent designer adding a flagellum to E. coli, we must envision the bacterial cell as a "receptive medium" to which the designer, in word-like fashion, imparts information concerning the process of assembling a rotary propulsion system. Might we find it difficult to understand how this designer-speech works? Yes, but that is not unusual in science, suggests Dembski. "We do not understand how quantum mechanics works, but we know that it works. So too, we may not understand how an unembodied designer imparts specified complexity into the world, but we can know that such a designer imparts specified complexity into the world."[31] Perhaps, but how might we come to know that something has been intelligently designed?
The signs of design
How would we come to know that something was intelligently design? It's very straightforward, says Dembski.
There does in fact exist a rigorous criterion for discriminating intelligently caused from unintelligently caused objects...I call it the complexity-specification criterion. When intelligent agents act, they leave behind a characteristic trademark or signature-what I define as specified complexity. The complexity-specification criterion detects design by identifying this trademark of designed objects.[32]
Whenever we infer design we must establish three things: contingency, complexity, and specification.[33]
An object/event is said to be contingent if, while it is fully consistent with natural laws, it is not wholly determined by them and represents only one outcome among several possible outcomes of natural processes. Complexity is related inversely to probability. Highly complex objects have a low probability of being actualized naturally. Dembski looks for objects whose probability of actualization by natural means is less than what he calls the "universal probability bound," which has the value 10-150. For some event/object to be specified it must exhibit a distinctive pattern that is detachable from the particular event/object itself. A detachable pattern might, for instance, correspond to some independently derivable sequence of numbers or letters that has no necessary connection to the object/event being subjected to the complexity-specification criterion. For example, if SETI researchers received a radio signal representing the first 100 prime numbers they would be justified in concluding that the signal exhibited a detachable pattern that had no necessary relationship to the electromagnetic waves that carried it.
In Dembski's language, if some event/object is contingent (not the outcome of any deterministic natural law), sufficiently complex (its probability of natural actualization is less than 10-150), and specified, then it exhibits specified complexity. The central argument of No Free Lunch is that objects/events that exhibit specified complexity cannot be actualized by natural processes alone and must, therefore, be the outcome of intelligent design, in the sense consistent with the way in which all of the key terms have been defined above.
Establishing the contingency of some event/object is ordinarily a rather simple matter. Establishing complexity and specification, however, is difficult (perhaps impossible), as our case study of the bacterial flagellum will illustrate.
E. coli and its Rotary Propulsion System: Dembski's Flagship Case for Design
Escherichia coli is a species of bacteria commonly found in the human intestinal tract and has been used extensively for studies of molecular genetics. Its single, rod-shaped, prokaryotic cell is surrounded by a rigid but porous cell wall. Immediately inside the cell wall is the plasma membrane, which effectively functions as the barrier between the interior of the cell and its external environment. The nucleoid within the cell contains the cell's circular DNA molecule, which houses E. coli's genetic information.
The genome of E. coli – the instructional information residing in the genetically relevant portion of its DNA – consists of about 4.7 million base pairs, representing approximately 4000 genes. These genes specify the particular character of the numerous RNA and protein molecules that carry out the multitude of diverse tasks that enable the cell to act and interact as it does. The formation, structure and functions of the cell and its component parts are expressions of the information coded in the base pair sequences that comprise the E. coli genome.
Protruding outward from the E. coli cell wall is a hair-like filament made of the protein flagellin. The base of the filament is attached via a bent "hook" structure to a miniature rotary drive mechanism embedded in the plasma membrane and constructed from several types of protein molecules. This configuration of motor, hook and filament constitutes the flagellum system. The energy for the flagellum's rotary motion is derived from a proton gradient across the bacterial membrane.
A cutaway sketch of the flagellum, complete with its rotary motor system, appears prominently on the front cover of Dembski's book, No Free Lunch. Dembski uses the bacterial flagellum as the principal specific example of what he considers to be an intelligently designed biotic structure.
The flagellum is an acid-powered rotary motor with a whip-like tail whose rotating motion enables a bacterium to navigate through its watery environment. Behe shows that the intricate machinery of this molecular motor-including a rotor, a stator, O-rings, bushings, and a drive shaft-requires the coordinated interactions of about thirty proteins and another twenty or so proteins to assist in their assembly.[34]
On a Darwinian view, a bacterium with a flagellum evolved via the Darwinian selection mechanism from a bacterium without a flagellum. For this mechanism to produce the flagellum, chance modifications have to generate the various proteins that constitute the flagellum and then selection must preserve them, gather them to the right location in the bacterium, and then properly assemble them.[35]
With regard to a particular biochemical system like the bacterial flagellum, intelligent design asserts that "No undirected natural process could produce this system"[36]
In the eyes of design theorists like Behe and Dembski, the bacterial flagellum presents the Darwinian mechanism with an insurmountable problem. Employing some of the ID vocabulary that we have already examined, the nature of the problem as they see it can be stated as follows:
1) The bacterial flagellum displays specified complexity.
2) Specified complexity in biotic systems cannot be generated by the Darwinian mechanism, which relies on chance.
3) Therefore the bacterial flagellum must have been intelligently designed-that is, it could have been actualized only with the assistance of form-conferring interventions by an unembodied intelligent agent.
As I see it, each of these three statements could be challenged, but it should be clear that if the first of these fails, then Dembski's whole system of design inferences built on the premise that specified complexity is demonstrably present but naturally impossible also fails. Therefore, let us examine statement 1) more closely.
To say that the bacterial flagellum exhibits specified complexity requires the demonstration that the flagellum is both complex and specified, where the meaning of each of these two terms must be taken from Dembski's development of the complexity-specification criterion. We shall deal with each of these two requirements individually, beginning with complexity.
NOTES:
23 See No Free Lunch, pp. xvi-xvii.
24 NFL, p. 330.
25 NFL, p. 112.
26 NFL, p. 326.
27 NFL, p. 326.
28 NFL, p. 334.
29 NFL, p. 335.
30 NFL, p. 343
31 NFL, p. 343
32 NFL, p. 6.
33 NFL, p. 8.
34 NFL, pp. 249-250.
35 NFL, p. 250.
36 NFL, p. 272.