Varieties of Design Arguments
Metanexus Sophia. 12,302 Words.
“The purpose of this paper is to examine some specifically philosophical questions about the current debate in selected North American public schools about including what is commonly called “intelligent design” (ID) as part of the schools’ official science curriculum. The issues I will raise focus around two broad questions: First, what is the logical status of the arguments for and against ID? Second, may the arguments presented for ID be considered “scientific”? My analysis will be grounded in two related but nonetheless distinct disciplines of intellectual history – the history of western philosophy and the history of modern western European science.”
Varieties of Design Arguments
By Norbert M. Samuelson
The purpose of this paper is to examine some specifically philosophical questions about the current debate in selected North American public schools about including what is commonly called “intelligent design” (ID) as part of the schools’ official science curriculum. The issues I will raise focus around two broad questions: First, what is the logical status of the arguments for and against ID? Second, may the arguments presented for ID be considered “scientific”? My analysis will be grounded in two related but nonetheless distinct disciplines of intellectual history – the history of western philosophy and the history of modern western European science. Based on my historical analysis I will suggest some tentative answers to the two questions.
That the conclusions will only be tentative is a consequence of the methodology. So let me begin with a word about the methodology, why I have chosen it, and why conclusions cannot be more than tentative.
The first methodological consideration has to do with the use of the term “science” and the logic of truth claims within the sciences. There is no single definition of the term “science” that can be adequate for all uses of it by all so-called “scientists” at all times and in all places. This negative judgment seems to me to be inescapable even if we confine our description to modern (i.e., 17th century C.E. and beyond) western (i.e., what arises from all European civilization) culture. Minimally, the term “science” is subject matter dependent, so that what might count as a line between science and non-science in one field could not be drawn in a very different science in the same way. Claims that may logically count as “scientific” in one discipline would appear as mere opinions in a different discipline whose subject matter can yield a much higher probability in principle. Similarly, different epistemic possibilities for truth claims will also determine what kind of methodology is or is not “legitimate” in different sciences. There are, for example, significant differences between the epistemic level of methods used and truth claims made in any life science than there are in another kind of physical field such as chemistry or physics. These differences are equally present in comparing the life sciences with the so-called social sciences and the humanities. (Under “social science” I am thinking primarily but not exclusively of psychology, sociology, and anthropology; by “humanities” I am thinking primarily but not exclusively of philosophy, history, and religious studies.) In general the more complex with respect to elements to be considered and the more dynamic the relations between the elements are the lower the line of probability legitimately required for truth claims in separating what is considered to be “knowledge” as opposed to “reasoned opinion” and the less the forms of legitimate argumentation used resemble what logicians would call “demonstration” or “proof.”
The second methodological consideration has to do with the limited applicability of generalizations about what collections of people think and say. Sociologists and anthropologists are primarily concerned with the views of all members of a group irrespective of how the quality of those beliefs varies. In contrast philosophers and intellectual historians are primarily concerned only with the views of those members of a group whose views are most rigorous and/or most influential. “Most rigorous” is a judgment about how carefully the thinkers have worked out their views with respect to clarity and logical consequences as well as how informed the believers are of relevant evidence (which includes what other thinkers say and argue). Not surprisingly, given the different interests, the kinds of beliefs upon which philosophers and intellectual historians focus often represent the beliefs of very few people, even in the groups considered, while the kinds of beliefs upon which social scientists concentrate are more often than not far more confused and less thought out than they need be for evaluating the epistemic quality of the claims that are relevant to a given question. Hence, it is not surprising, for example, that the beliefs of most Jews about God (for or against) bear relatively little resemblance to Maimonides’ theology and that very little knowledge of philosophical methodology is needed to discredit the intelligibility of the former claims. Similarly, it would be misleading at least to use the philosophical theology of Thomas Aquinas to represent what most Roman Catholics believe, and conversely it would be unfair to judge the reasonableness of Roman Catholic faith on a survey of the religious belief of most people who regularly attend a mass in (for example) south Phillie or the Westside of Chicago.
Philosophers of religion are mostly concerned with the epistemic quality of religious beliefs, hence the beliefs they discuss rarely reflect at a realistic level what most religious people believe, and that deficiency is proper. Similarly, in this paper I will look at what in my opinion are the best statements of ID and towards that end it makes no difference what other advocates of ID think or say, irrespective of the institutions they represent. Similarly, when I consider positions on Darwinian evolution, I am solely concerned with positions that I would judge to be logically and coherently the best, irrespective of what other advocates of Darwinian evolution claim, be they politicians in governments, or teachers of science in public schools, or professors of life sciences in western universities.
How then are we to decide on what is best? That question has already been given an initial answer. I will select what I consider to be logically the best and politically the most influential views. However, it is rarely the case that what is best is the most influential. Furthermore, there are many different ways to be the best, different ways to be influential, and rarely is a single view by a single believer the best in every respect and the most influential in every way. How then should I choose between multiple bests? The solution – at least for me—is not to blend the different voices together and present them as a single position. In general, the positions taken by good thinkers are distorted when they are removed from their literary and historical frameworks, and this is a kind of distortion that I wish to avoid. Hence, for each of the two major positions to be considered in this essay I will focus on the thought of a single thinker in full recognition that by doing so I will be ignoring other relevant thinkers who in important ways make different sorts of claims. I am willing to defend my choices even though I recognize that in making them I render my conclusions to be only tentative, for it may well be the case that on reconsideration in terms of different thinkers I might alter my conclusions.
In this paper I will focus on the presentation of intelligent design by Michael Behe in Darwin’s Black Box2. His argument rests on certain scientific claims he makes. I will accept them at face value, i.e., I assume that the presented generalizations are stated correctly and are based on accepted methods of research in biology. (I, trained in philosophy, cannot in this respect function as a judge.) Instead my interest in the book is limited to the consequences about philosophical-theological topics based on the stated science. More specifically, I am concerned with the logical quality of his claimed trans-scientific conclusions and with the implications of the public debate of his position for defining science. For the logical issue again, for the same kinds of methodological reasons given above, I will turn to a single primary source – Richard M. Gale’s On the Nature and Existence of God3.
Next I will consider the claims of a now standard interpretation of Darwinian evolution as it is stated and defended by Richard Dawkins in The Blind Watchmaker.4 Then I will conclude this paper with some personal reflections on the nature of science as it emerges from the Behe-Dawkins debate out of a peculiarly historical perspective, which grows out of my current studies in the history of science. In this case the focus for comparison will be on the well-documented scholarly puzzle of Newton’s denial of hypothetical-deductive logic in his final reflections on his work as a theoretical physicist in his Principia.5
I. Is Intelligent Design (ID) a good argument?
A. Michael Behe’s Argument for Intelligent Design
Behe’s Darwin’s Black Box is no more a work of biology than is Dawkin’s The Blind Matchmaker.6 Rather, both books are works by recognized scientists7 about the implications of their knowledge of current scientific practice for future endeavors in science and for the relevance of science to culture in general. As such both books are informed studies in intellectual history and should be treated as such.
Behe’s book is a sustained argument for biology to adopt what he calls “intelligent design” over what he believes to be Darwin’s interpretation of evolution, which Behe affirms to be the dominant understanding of evolution today in the life sciences.8 Stated in its simplest terms, Behe points to four specific kinds of examples in molecular biology that exhibit what Behe calls “irreducible complexity.” He then argues that ID offers a better explanation of these and all other examples of irreducible complexity than can Darwinian evolution. The four examples are presented in chapters three through six. The argument about them is presented in chapters eight through ten.
1. Examples of Irreducible Complexity
Behe’s first example is of a structure called “cilium” which consists of a fusion of rods (called “tubules”) that are made up of proteins. These fused protein compounds attach to simple cells (for example, sperm), and enable the cells to move in the liquid (for example, semen) that fills their more complex host. Behe notes that the cilia function like the oars of a boat (59). On the analogy the cilia are the oars for the sperms (cells) moving in the semen sea within the universe of male and female reproductive organs.
The point of his cilium/oar analogy is explicitly stated on pg. 57. The reproductive systems of which Cilia play a part function as “(m)echanical examples of swimming systems” which are intelligible solely when seen as parts of such a system. Behe then asserts a second order analogy to explain the cilium function as “swimming.” He now compares the oar that is analogous to the cilium to a “mousetrap,” and then comments that a mousetrap without a spring is “a swimming system without a paddle, motor, or connector” without which the (reproductive/swimming) system would be “fatally incomplete.” (pg.57) Then Behe adds that “(b)ecause the swimming systems need several parts to work, they are irreducibly complex.” (pg.57) In other words, “irreducible complexity” is an attribute that characterizes a biological system that has multiple parts and the activity of at least some of those parts cannot be understood without reference to the system itself.
A second illustration, from American popular culture of the early 20th century, introduced to make his critical category of irreducible complexity more comprehensible, is the machines that the comic strip character, Rube Goldberg, would make, always operating in the most complex way imaginable to provide functions that always could have been provided in far more simple ways. In Behe’s words, it “is a system composed of several interacting parts that contribute to the basic function, where the removal of any one of the parts causes the system to cease functioning.” (pg. 76)
The comic book illustration of what Behe means by irreducible complexity shows that a biological system is to be defined by a set of multiple discrete actions that together produce an activity distinct from the more primary actions, and that each member of this set is necessary to the set, such that without each activity there could be no collective product. In addition, Behe seems to suggest (although he does not explicitly say so) that the individual discrete, more primary, functions also depend for their performance on the functioning of the whole. In other words, “irreducible complexity” is present as the defining characteristic of any complex entity that is “organic,” where for something to be organic means that it is composed of a set of simpler parts such that the well-being of the constituents are mutually dependent (for at least self-defined prosperity if not for existence and persistence) on each other and on their collective whole.9
Hence, any kind of complex entity that is organic will do equally with cilia to exemplify things that are irreducibly complex. Behe describes three other examples that he draws from his own research and teaching interests as a molecular biologist. However, as the above discussion of his first example should make clear, there is nothing of logical interest special about his examples from molecular biology. All organisms10 are such that the whole and each of its essential parts are mutually entailing with respect to both generation and preservation, such that if the parts were to exist independent of their participation in the whole they would be entirely different things than they are as defining constituents of the compound organism.11
2. Analysis of Behe’s Argument
Chapter 8 begins Behe’s use of his category of irreducible complexity to argue for his central thesis, viz., that at least at the molecular level what I call “organic unity” can only be understood as a product of what Behe calls intelligent design. ore accurately, the positive claim, viz., that the phenomena in question exhibit intelligence, is simply taken for granted. Instead Behe’s argumentation focuses in the related negative claim, viz. that no alternative system of explanation that modern biologists invoke can successfully explain organic unity. Behe grants at least in principle that given the modern history of the field of western biology, intelligent design may be invoked as a causal explanation only if the phenomena in question cannot be explained in any other way.
In fact Behe’s argument is subtler than I have stated. He summarizes his negative argument against what he considers to be Darwinian evolution on pg.176 where he says that he is not denying that “evolution, random mutation, and natural selection” do occur in nature. He does grant, for example, that we may effectively use any number of forms of “system analyses” from computer sciences, to model evolutionary processes. However, no system analysis itself can explain what “has caused complex systems to form.” In other words, Behe invokes intelligent design not as an alternative to the kinds of efficient causes (in Aristotle’s language) that explain the mechanism of evolution but as an inescapable appeal to explain the origins of these complex processes. Again to use Aristotelian language, Behe’s question is about why there exists the phenomena of organic life and not about how it occurs, for insofar as Behe the molecular biologist addresses how questions in this book, he gives the same kinds of answers that all biologists would give – mechanical explanations with reference to material entities as efficient movers.
At this point it should be clearer what the argument with evolutionary biologists is about. The question is not, can appeals be made, as modern Darwinian scientists and philosophers do, to principles such as “evolution, random mutation, and natural selection” to explain changes within the historical process of the evolution of living things. Clearly and explicitly Behe says that they can. The issue is, can these same Darwinian principles be employed to explain the genesis of the multiple interrelated and discrete processes of evolution itself, and this possibility Behe denies.
What should be clear by now is that Behe is not really talking about the kinds of concrete processes at all to which standard contemporary biologists confine their attention – viz., processes like (in Aristotelian terms) genesis and corruption, or health and sickness. Rather, Behe is concerned with the broader questions of the origins of the universe of living things themselves, viz., of the creation of the earth. And these questions have traditionally been a subject matter more appropriate to philosophers than biologists.
Of course, there is ample precedence for scientists to discuss these kinds of philosophical questions with specific reference to science. But there is something distinctive about the way that Behe raises them. First, he presents them as legitimate questions within the domain of the discipline of biology. Second, he raises the issue of creation and (by implication only) a creator with reference to biology.12
I will reserve the question of the legitimacy of discussing the possibility of a creator within science itself to the final section of this paper, and the question of the general legitimacy of design arguments such as those that Behe has presented to the next section. Here, however, before I conclude this first section of the paper that deals directly with Behe’s claims, I do want to make one qualification on what I have said that is important to understanding Behe’s argumentation in Darwin’s Black Box.
As I noted above in the previous footnote, it is not entirely accurate to say that questions about design arguments from the data of the sciences have arisen in the past exclusively from the more physical sciences. There are many notable exceptions to this generalization (which, like most generalizations, is only true generally). For our purposes the most notable exception is the theological biology of William Paley. It is his arguments for the necessity of intelligent design in biology that occupy much of the attention of both Dawkins and Behe. Let me therefore here say a word about Paley, especially with reference to the theological consequences he draws from his study of the mechanics of human vision.13
3. William Paley and Human Vision
It is interesting that Dawkins, no less than Behe, speaks well of the writings of William Paley. It is true that the “creationism” of Paley heads the list of Dawkin’s so-called “doomed rivals” (pg. 288), but the list is for Dawkins composed of serious biologists. It includes not only Chevalier de Lamarck and T. D. Lysenko14 but also Stephen Jay Gould, Niles Eldredge, the distinguished early twentieth century founders of mutationism (Hugo de Vries and William Bateson), the “inventor” of the term “gene” (Wilhelm Johannsen) and the discoverer of the chromosome theory of heredity (Thomas Hunt Morgan), all of whom are major scientists and most influential figures in the history of Genetics. Let just one quote suffice for the value that Dawkins attributes to Paley.
Dawkins presents a brief history of the use of design arguments from the time of the ancient Greeks up to the time of Paley just before the ascent of Darwin. About Paley Dawkins says the following:
Compared with that of the Greeks, Paley’s argument is much improved. Although in Natural Theology he gives many poor examples of design (akin to Diogenes and Socrates), he also frequently hits the nail on the head. Among other things Paley writes about discrete systems such as muscles, bones, and mammary glands, that he believes would cease to function if one of several components were missing. This is the essence of the design argument. However, it must be emphasized for the modern reader that, even at his best, Paley was talking about biological black boxes: systems larger than a cell. Paley’s example of a watch, in contrast, is excellent because the watch was not a black box, its components and their roles were known. (pg. 212)
A reader cannot help but think that Behe had Dawkins’ The Blind Watchmaker in mind when he wrote his book, and this passage specifically in mind when he entitled his book, Darwin’s Black Box, for Behe presents Darwin in precisely the same way that Dawkins presented Paley. To paraphrase Behe, Darwin was a great scientist, but there was much about biology he could not know at the time that he wrote and that is why he thought he could explain evolution without intelligent design, for all of Behe’s claims about design turn on phenomena beyond the veil of the knowable in Darwin’s world of pre-genetic, pre-molecular biology.
Taking Dawkin’s praise of Paley’s watchmaker analogy, Behe turns it against Dawkins. As Behe says, Paley’s watch reference “is precisely correct – no one would deny that if you found a watch you would immediately, and with certainty, conclude that it was designed.” (pg. 215)
Clearly Behe marks himself here as a disciple of Paley, and that what he presents in Darwin’s Black Box is an update of Paley’s use of the argument from design for the existence of God. It is now time to look at how such arguments fair in modern studies in the philosophy of religion.
B. Richard Gale’s Analysis of Modern Philosophical Design Arguments
As long as human beings have tried to exhibit the existence of God through language they have used some version of the argument from design. Maimonides, who himself lived in the twelfth century, attributed the origin of the argument to the first generations of human civilization to arise after the expulsion from the Garden of Eden15. However, the argument was used to identify the wrong entity as God and, by so doing the development of the design argument is in part responsible for the rise of idolatry.16
More specifically, Maimonides speaks of an early civilization called “the Sabians” who developed the art of agriculture and used that experience to establish the worship of deities. They argued that just as a garden exhibits the order that was imposed upon the land by the gardener, so the universe exhibits an orderliness that suggests the existence of a deity who ordered it. However, the argument cannot establish just who is the order-er, so that, left to their own intellectual devices, lacking any direct revelation from God himself, the Sabian men of wisdom falsely concluded that the “gardeners” of the structured universe must have been the stars. Idolatry begins, therefore, from a misidentification, based on insufficient data, which the creators, correctly inferred through the use of analogy to exist, and properly judged to be worthy of praise, are the “celestial bodies.”
The problem, correctly identified by Maimonides himself, is that nothing can rationally be demonstrated by the use of analogy. Analogy is a tool of rhetoric, a strategy for using language in a way that will be persuasive to the listeners. It has nothing to do with logic, which presents strategies by which what we know by other means (such as direct experience or reliable testimony from qualified witnesses) can be extended (by valid inferences) to yield new knowledge.
In general, while the classical rabbinic philosophers believed that God’s existence, unity, and oneness could be rationally demonstrated without an appeal to revelation, they never considered any form of design argument to be logically compelling. Furthermore, many Christian scholastic philosophers, notably Thomas Aquinas, agreed with Maimonides and followed his example. However, presumably by the seventeenth century there existed, at least among the British Christian theologians, thinkers who did believe in the logical value of a design argument, for David Hume, in his Dialogues Concerning Natural Religion, felt it necessary to demonstrate the limitation in this form of argument.
In general, for the most part philosophical theologians, both Jewish and Christian, continental and English-speaking, have not employed the argument for design to establish the existence of God. However, there are notable exceptions to this judgment, one of whom is William Paley. Yet I know of few major Christian and of no Jewish philosopher who so argues. However, the argument has reappeared in more recent times as a form of argument not for the existence but for the non-existence of God.
A recent PhD. Dissertation written by my student Michael Valle (completed in 2004) presents a rigorous and thorough logical analysis of this new kind of philosophical design argument that is based on post-Holocaust invocations of a principle called “the hiddeness of God.” The better logical forms of these arguments for God’s non-existence root themselves in actual examples of unprovoked suffering of children. These arguments belong more generally to a class of 20th century, English language arguments for the non-existence of God that are called “the deductive argument from evil.” Richard Gale presents a systematic and rigorous discussion of them in chapter 4 of his On the Nature and Existence of God.
1. The Deductive Argument from Evil
At its most general level the argument claims that if by God we mean an entity of unlimited power and goodness, then God’s existence entails that evil does not exist, but since evil does exist, this deity necessarily does not. The most influential version of it was constructed by J.L. Mackie in 1955.17 We will not consider here the details of his argument, but there are a couple of features worth pointing out.
First, Mackie draws a distinction between existential and attributive uses of the terms “omnipotent” and “wholly good” and emphasizes that in his argument the predications are to be understood existentially. It is an important distinction because it saves him (at least initially) from the charge of theological ignorance of the established tradition from Maimonides through Aquinas that it is in principle impossible to make univocal affirmative statements about a creator whose existence is necessary in a language that builds semantically on a base of empirical experience whose range is limited to speech about inherently contingent creatures and created events.
Second, the claim that God is omnipotent entails (what Gale calls “quasi-logical rules”) that an omnibenevolent being (i.e., a being who is perfect in both power and goodness) eliminates or prevents every evil that he is capable of eliminating or preventing and there are no limits on what he can do. Therefore, the recognized existence of any contingent evil, i.e. an evil that logically need not occur, demonstrates this God’s non-existence. The main line of defense against the argument is to demonstrate that in fact (if not in principle) there can occur no contingent events that on final analysis are evil or that no unredeemable evil in this universe is contingent. Defenses so structured logically are called “free will defenses.” Of them the most influential in English-language academic circles of the study of the philosophy of religion is the version stated by Alvin Plantinga in his 1967 book, God and Other Minds.18
2. The Free Will Defense Against the Deductive Argument from Evil
We will not here consider the logical details of Plantinga’s argument and we will restrict ourselves only to comments on his general strategy. There are two critical points that I want to emphasize. The first is that Plantinga must defend the claim that it is logically possible that God is contingently unable to create free persons who always do what is right. The second is that his defense necessitates that he must in some way modify what it means to claim that God is omnibenevolent.
Again we will not go through the details of any of these logical moves. For example, in one of several versions of Plantinga’s argument he suggests that what it means to say that someone is “free” is that he is “unfettered,” which amounts to a claim that the person choosing to do good or evil is not in any sense “brain-washed” to make his choice. In other words, human beings in general do not have, to use a biblical expression, their “hearts hardened” as God in Exodus hardens the heart of Pharoah so that he will not be free to give the children of Israel permission to leave Egypt. Still, Gale, in his analysis, rightly concludes that this move in no way helps Plantinga to save his argument, so that the free will defense cannot overcome the force of at least a revised version of his deductive argument from evil.
So much for what Gale himself says about this argument, most of which I accept as correct. However, I would want to add (and defend) the following evaluation of the discussion. Mackie’s argument for God’s non-existence on final nalysis has neither m