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DNA, intelligent design and misleading metaphors

Posted on: Sunday, 22 June 2003, 06:00 CDT

WHAT MAKES ID SO INTUITIVELY APPEALING?

As our tools of exploration become more sophisticated, a correspondingly sophisticated level of complexity emerges in the objects being explored. The Hubble Space Telescope shows us a universe far more active than originally suspected, populated with phenomena that rival the best of science fiction. The recent mapping of the human genome has yielded a blueprint for the stuff of life that is enormously complex. This, along with the recent fruits of scientific pursuits in areas as diverse as particle physics, paleontology, and neuroscience, has led to an enhanced recognition of the complex order of the natural world. In fact, the organization that is being revealed is so intricate that a few scientists are beginning to believe that it is, well, just not natural.

These scientists claim that, as our knowledge of the natural world increases, it grows increasingly difficult to account for the natural world using naturalistic mechanisms. They think it improbable that a universe such as ours could be an accidental by- product of natural processes, in the words of biochemist Michael Behe, an "irreducible complexity" at the molecular level defies naturalistic explanation. This level of complexity and interdependence, the argument continues, suggests intelligent design. The purposeless mechanism of natural selection is not sufficient to explain the living world, and it seems very unlikely that something as elaborately wrought as DNA could have an ancestor that came into being as a result of a sequence of fortuitous collisions among protein molecules. The alternative is that the organization of things is not fortuitous, but the result of some kind of grand plan: life didn't just happen willy-nilly, but was designed to be as it is.

A new permutation of the idea of intelligent design, one that claims to be noncommittal regarding any kind of religious view, is becoming increasingly popular. But it is by no means a new idea; in fact, it is at least as old as Plato. Perhaps its best-known version comes from the late eighteenth century: William Paley's watchmaker analogy. Briefly, if I found a rock lying on the ground, I would have no problem accounting for its presence and structure through reference to well-known natural forces: volcanic action, erosion, etc. But were I to stumble across a watch, even if I knew nothing of watches, the structure of its workings would force me to conclude that it was an artifact intelligently designed and created for some purpose. It would be impossible for the chance operations of natural lorces to first create and then assemble the complex array of gears and springs so that they worked together with such precision. But if we look closely at the natural world, we find systems of interaction, interrelation, and interdependence no less complex than the internal workings of a watch. The wing of a bird, the human eye, the food chain, the regular progression of the seasons-these things are surely the result of a creative intelligence.

Even before Paley published his watch analogy, David Hume had already developed a fairly thoroughgoing critique of the design argument.2 According to Hume, first of all, the universe-any universe that consists of a collection of interacting and interdependent parts, that is, any universe at all-will appear as if it were designed. The addition of natural selection to Hume's suggestion makes it clear that complex interrelations among constituent parts of a universe can develop through time, and that the conciseness of fit among the parts-for example, a bird whose beak is adapted precisely to fit the shape of the flower from which it typically feeds, along with the flower that is shaped and colored to attract a particular kind of bird-can suggest a pre-planned arrangement even though no such arrangement exists. Hume also suggested that the machine analogy itself was a weak one. The natural world is not very much like a machine. The kinds of relationships found in the natural world are typically not as clearly defined as the relations among the gears of a timepiece (though recently we have found many that are this precise, and more). The kinds of relationships found among constituents of the natural world are more in line with the relationships among the internal structures of living organisms than those found in human artifacts. Further, the analogy between the relationships among constituents of the natural world and the relationships among the organs of a living creature cannot be used to support the intelligent design of the natural world in any case, because living creatures are themselves part of the world's organization that we are trying to account for in the first place. Finally, Hume pointed out that even if the universe is patterned after an intelligent design-and is hence the product of an intelligent designer-that still provides no evidence of anything remotely resembling the wise and good Christian God. (In Hume's time, and perhaps no less so in my own, most of those promoting the idea of intelligent design have had a specific religious agenda and a particular designer in mind.)

How does Hume's critique apply to the modern permutation of the intelligent design argument, an argument now armed with modern biochemistry and astrophysics? Proponents of intelligent design claim that the complexity of the world and the number and subtlety of the adaptations among its constituent parts outstrip anything that could possibly result from the functioning of dumb naturalistic mechanisms. But this seemed as true in Paley's day as in our own. Yes, our awareness of the complexity of the world has greatly increased, but so has the complexity of the mechanisms that we postulate as explanations. The very nature of the scientific enterprise ensures that our knowledge of the facts, our awareness of the observable details, will always run slightly ahead of our ability to account for them. Empirical science first details the phenomena of interest, then tries to understand the mechanisms behind the phenomena. Recently, there has been a dramatic increase in our knowledge of some of the details; the lenses through which we are able to observe the natural world provide us with a dizzying level of acuity. As a result, some of our long-functional explanatory mechanisms, at least in their present form, may appear to be no longer entirely sufficient. But that does not mean that we are forced to concede intelligent design. What it means is that the theorists have to hunker down and get to work on revisions. This is the way science has always worked.

So the first part of Hume's critique-the suggestion that any universe will appear designed, whether it was or not-still applies. The second, however-the suggestion that the machine metaphor is weak- may have been weakened itself, by the sheer productivity of our modern metaphors. The machine metaphor is at best a rough analogy: the world really isn't very much like a machine. But DNA is very much like a kind of code. Because of this, the modern version of the design argument is potentially more appealing than was the machine version of Hume's time.

In the modern version of the design argument, God is not a mechanic but a sophisticated computer programmer. DNA is like a computer code; life is what happens as this code is compiled in an organic system and executed within the environment for which it was designed. The danger in all of this has to do with the temptation to take the metaphor too literally. In Hume's time, you didn't have to be a watchmaker or know exactly how the internal workings of a watch functioned in order to understand what kind of a thing a watch was, and you didn't have to be a botanist in order to understand that a plant was a thing of a different kind. But very few people today understand the biochemistry behind DNA (or the physics behind a black hole, the mountain-building effects of plate tectonics, etc.). Perhaps the majority-including many scientists-think DNA really is a kind of code. Popular descriptions of DNA have included the terms blueprint and code so frequently that many have started seriously to assume the necessary existence of a grand architect or cryptographer. Perhaps the modern resurgence of the idea of intelligent design reflects a simple failure to distinguish the target from the metaphoric vehicle, a failure to recognize that when we call DNA a kind of code we simply employ a highly functional analogy.

Design, of course, implies a designer. But more than that, design implies purpose. One of the things the materialist explanations promoted by science surely lack is purpose. On the naturalistic view the universe has no purpose, it just happened. There was a big bang, perhaps, and things just sorted themselves out the way that they did because of universal laws having to do with gravity and time and space. If you want to know the "why" of things, you simply look to the "what" and the "how" of things. An adequate explanation in science is merely a description formulated at a certain level of mechanistic (or probabilistic) detail; all questions in science, even the ones that start out as "why" questions, ultimately reduce to "what" and "how" questions.

The ultimate reason for things is something about which science remains forever mute. According to science, nature doesn't nee\d any ultimate purpose. The lack of purpose, however, can be a difficult thing for some of us to accept; we are, after all, purposeful, goal- directed creatures. The nature of our bias toward goal pursuit can lead us to act as if there were an ultimate reason for things. Consider that we do not pursue our goals in a simple linear fashion, one after another; rather, our goals are hierarchically structured. Our higher-order goals require the formation and successful pursuit of numerous subgoals. In this way our nontrivial activity is directed at achieving goals that are not ends in themselves, but means to even greater ends. A student studying for an exam, for example, has the proximal goal of performing well on the exam. But performing well on the exam is not the ultimate end to which his or her studying behavior is directed; it is a means to the end of getting a good grade in the class, which is a means to the end of graduating with a high GPA, which is a means for getting into graduate school, which is a means for getting a graduate degree, which is a means for getting a certain kind of job, which is a means for. . . .

On the other hand, if the universe has no purpose, it is easy to conclude that then our presence in the universe has no purpose. If our lives have no ultimate purpose, then even our most worthy pursuits can't be directed at any ultimate end. The lack of ultimate purpose at the upper end of the goal hierarchy can filter down to our daily activities and lead to an existential crisis. But if the universe is designed, then it is easy to conclude that we must be here for a reason-there must be some ultimate purpose external to us. It is not necessary that we have any understanding of what this ultimate purpose is in order to avert an existential crisis; the mere fact that we believe one exists is sufficient. This state of affairs can serve to bias even the most objective evaluation of the necessity of intelligent design.

Our goal-directed natures may enhance the appeal of intelligent design in other ways as well. For example, because humans are purposeful beings, understanding the actions of others is typically a matter of discovering the purposes to which these actions are directed. Much of our social interaction involves consciously or unconsciously analyzing the motives and intentions of those around us-and we are very good at it; we evolved as social creatures. When we turn our attention away from the social world toward the phenomena of nature, it only makes sense to use the conceptual tools that we can wield most effectively, namely, those tools we have acquired to deal with intentional behavior in the social world. The fact that these tools are frequently inappropriate may go unnoticed.

Children and people in primitive societies live in a pantheistic world: the objects of nature are thought to have their own essences and often even minds of their own. Natural phenomena such as wind, rain, the change of seasons, and the movement of heavenly bodies are understood as manifestations of purposeful behavior by intentional entities. But pantheism is perhaps only a natural consequence of anthropomorphism-the metaphoric use of what we know best: us. Science is in many respects the antithesis of pantheism, but scientific explanation and discussion make extensive use of anthropomorphism: we say that the actions of matter are governed by certain forces; quarks participate in holding the nucleus together; electrons behave like both a particle and a wave; tectonic plates join and separate in a constant dance; the river carries sediment downstream; each body organ performs a specific job; prefrontal brain areas direct and control motor activity. Thus, the idea of intelligent design might be, at least partially, a result of the application of anthropomorphic thinking to the complex details of the natural world.

"What is the purpose of the universe?" is a meaningless question according to the scientific worldview, but thinking about the phenomena of the natural world in terms of intentional action and intelligently directed purpose, even when we are aware that our anthropomorphic metaphors are not literally true, can disguise the question's absurdity.

It is unlikely that we will ever fully grasp our situation. It may be in principle impossible to gain anything remotely resembling an accurate rendition of some true state of affairs in the universe. For one thing, we are part of that universe, we represent but a small subset of the complexity of the world around us, and our conceptual apparatus functions according to some of the very operations it is trying to adduce. Our situation is analogous to trying to see directly what our own eyes look like. As philosopher of science Hilary Putnam reminds us, we simply cannot get outside of our own skin.3

The frustration produced by a powerful desire to know, coupled with an epistemic situation that ensures the opacity of certain domains of knowledge, adds to the allure of the idea of intelligent design. Moreover, this idea brings with it the security of an implied ultimate purpose. Hume's criticism of the design argument, however, still applies today. The world is a more complicated place now than it was two hundred years ago, and the complexity of our metaphors has likewise increased. Chances are the world will be even more complex two hundred years hence, and it will be just as difficult to generate serviceable naturalistic explanations then, just as tempting to shrug our shoulders and say, "God did it." But complexity does not mean intentionality. Adding a penetrating intelligence to the fabric of the universe is not necessary to account for the complexity that is revealed by our technologically sophisticated observations, nor does not solve the problem of the universe's existence. It merely compounds the mystery. If we allow that the universe or any component of the natural world was intelligently designed, then we not only have the nature of the design itself to untangle, but we have the nature of the designing intelligence to account for as well.

"The very nature of the scientific enterprise ensures that our knowledge of the facts . . . will always run slightly ahead of our ability to account for them."

"Perhaps the modern resurgence of the idea of intelligent design reflects a simple failure to distinguish the target from the metaphoric vehicle."

Notes

1. Michael Behe, Darwin's Black Box (Simon & Schuster, 1996).

2. David Hume, Dialogues Concerning Natural Religion (London: 1779).

3. Hilary Putnam, Representation and Reality (Cambridge: MIT Press, 1988).

Mark R. Seely is an associate professor of psychology at Saint Joseph's College, Indiana.

Copyright Council for Secular Humanism Summer 2003

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