In this lecture, I’m going to talk about the argument from design. This is the last of the traditional Big Three arguments for the existence of God, identified by Kant and others. It claims that by examining the universe and the things it contains, we can see it must be the work of a supremely powerful, intelligent being, who is identified with God.

Though this was true to some extent of the Big Bang argument discussed last time, it really, really important to emphasize here how the argument from design differs from previously discussed arguments: it’s supposed to appeal not to general philosophical considerations, worked out from the office chair, but specific observations that we need to go out into the world in order to gather. This is important for two reasons.

First, it’s the sort of argument that strikes many people as at least having a chance at working. Starting some time around the 1600′s in England, there’s been a very strong tendency to doubt that office chair arguments can teach us much of anything, and that the only way to learn how the world is by going out and looking at it. This tendency began with the philosophers John Locke and Francis Bacon, but you can really see it at its best in David Hume. Hume was a terribly consistent philosopher, who’s hard to describe as ever having just one view on anything. Sometimes he suggested that no one can claim to know anything, so in picking our beliefs, religious dogma is as good as anything. Other times, though, he suggested that reasoning based on evidence, while imperfect, is at least better than metaphysics, which is so worthless we may as well burn books on the subject. So, if you read his /Dialogues Concerning Natural Religion/, you can see him discussing all the major arguments concerning the existence of God, but he devotes much, much more space to the argument from design. He likely viewed the cosmological and ontological arguments as metaphysics and therefore non-starters, but the argument from designed seemed more like science. Indeed, Hume has one of his characters in the dialogs argue that the argument is just like that used in modern astronomy, which had been a key part of the scientific revolution.

The other reason the argument from design is important is that it seems to avoid specific flaws of other arguments. Other arguments, I’ve said, often make a very vague, general claim that some thing is in need of explanation, and then claim, for reasons often unclear, that God is the only option. The argument from design, though, if done right, says “Look at the specific features of this thing. They specifically point to the thing being designed. And the nature of the thing also points to the thing being designed by a being far greater than human beings.” This gets you out of worries about the need for some kind of explanation for, say, God. This is analogous to what happens in science: we don’t say that chemical theory is true is true because of a general need to have something to say about how things work, and hey, chemistry does the trick. We say chemical theory is true because it explains so many specific features of things we see every day, and it explains specific data gathered in the laboratory. So we wouldn’t doubt the truth of chemistry, with that evidence, just because we couldn’t in turn explain the facts of chemical theory.

A warning: that strength of the argument from design only applies to an ideal formulation. As I indicated when I introduced the topic of God, a sloppy design argument can end up looking a lot like the crude cosmological argument.

In spite of this, there are two things that make teaching the argument from design difficult. The first is that the loudest proponents of the argument from design, these days, tend to be members of the anti-evolution movement. And often, the problems with their arguments aren’t mainly philosophical, the problems are mainly that they can’t get their facts straight. For example, they may claim that there are huge gaps in the fossil record that contradict what the theory of evolution says.

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Aside from showing you that slide, I’m not going to say anything about the fossil evidence for evolution. It isn’t my job to perform that kind of basic science education. If you’re interested in the science, I strongly recommend the website TalkOrigins.org, and there are also very good books on evolution out there that you can check out from the library. But I won’t be covering anything beyond broad ideas of evolution. I will point out, though, that if you’ve ever wondered why the scientific response to Creationism or Intelligent Design can be so venomous. Stephen Jay Gould, in his essay “Evolution as Fact and Theory,” said:

Faced with these facts of evolution and the philosophical bankruptcy of their own position, creationists rely upon distortion and innuendo to buttress their rhetorical claim. If I sound sharp or bitter, indeed I am—for I have become a major target of these practices.

Gould goes on to explain the specific ways in which his work was misrepresented. In general I recommend the essay, as it makes a good general introduction to evolution.

The second problem with teaching the argument from design: today’s proponents of the argument from design tend to be very, very concerned with showing you how their case is a scientific one, so they whip out all these impressive-sounding scientific claims, but fail to make clear how these claims are supposed to support the inference that God exists. So for me, it’s hard to pick out the arguments I’m supposed to be critiquing. Richard Dawkins calls this phenomenon “the Argument from Blinding with Science,” giving the rather extreme example of when the eighteenth century mathematician Euler supposedly said “(a + b^n) / n = x, therefore God exists.” Be wary of people who cite scientific facts and then assume, without explanation, that they’re evidence for God.

Before I talk about how the argument from design might be set up, I want to briefly cover not the evidence for evolution, but just what evolution is. It can’t be taken for granted that if the theory of evolution has problems, then God must exist, or conversely that if evolution is true, God doesn’t exist. It just isn’t obvious that either claim is true, they might be, but would need to be argued for. However, I wouldn’t want anyone to reject evolution and accept design based on a misunderstanding.

The key insight of evolution, relevant to the design argument is this: organisms can be fitted to their environment without any conscious design if they have variation which can both give them an advantage in the struggle for survival and be passed on to the next generation. Traits that increase your odds of survival get spread throughout the species. Importantly, it isn’t all a matter of chance: the initial source of variation is chance, but the process of selecting the fittest organisms isn’t. Mutations are random, which mutations persist isn’t. Also, creationists sometimes claim that natural selection only alters frequencies of existing genes, and can’t create anything new. While altering gene frequencies is the most basic thing natural selection does, this criticism ignores the fact that if a new, beneficial mutation appears by chance, natural selection can make that mutation dominant in the population, whereas without natural selection the mutation might not go anywhere, so to speak.

Sometimes in philosophy classes, it’s suggested that the most basic version of the argument from design is the argument from analogy: you point to human made things, and to life, or the universe, and say they’re similar, so if one is designed, the other is likely to be. More basic than this, though, may be the “isn’t it obvious” argument: isn’t it just obvious, when you look at life, that it was designed? People really talk this way, in my experience, though they do begin invoking analogies pretty quickly: when we look at human made things, we can see it’s just obvious that they’re designed, so we have the ability to see obvious design in nature. The argument from design is sometimes called the “watchmaker argument,” because of a famous defense of the argument from design, written around 1800 by a man named William Paley, which argued that when you find a watch on the ground, it’s just obvious that it’s designed. A modern design proponent may quote a scientist saying that cells are like miniature factories filled with molecule-sized machines, supporting the design inference.

The most basic objection is that the analogy isn’t very strong. There are a lot of differences between a watch and a tree. That’s obvious if anything is. If you study molecular biology—which I strongly recommend, by the way—you realize that the “molecular machines” aren’t much like human-built machines. They work on different principles: peptide chains, protein folding, hydrogen bonding, catalyzed reactions, things that aren’t central to human technology.

Worse, it’s not clear that we detect human design by its inherent obviousness. We have other humans around to tell us these things are designed, maybe we’ve seen some of them made ourselves. If you saw an unfamiliar piece of technology without knowing about its makers, you might fail to realize it was designed. My understanding is that before encounters with aboriginal people who used flint tools, many Europeans took flint arrowheads to be naturally produced fragments of rock. Or, consider the SETI program, the Search for Extraterrestrial Intelligence, sometimes invoked by design proponents. They’re looking for radio signals from an extraterrestrial civilization, not based on some criterion of obviousness, but based on the idea of looking for broadcasting on a narrow band, because we know one intelligent civilization (humans) does that, but we don’t know of any natural phenomenon that does that. In contrast, we lack reliable reports of God setting down to work on animals, or universes, so the analogy breaks down.

The more sophisticated way to present the argument from design is in terms of probability. There are several ways to set this up, but there’s one issue that arises for all versions: how on Earth do you calculate the probabilities? For example, one version of the argument from design, called the “argument from fine tuning,” relies on the idea of physical constants, things like how strong, overall, the force of gravity is. It’s claimed that if these constants were at all different, the universe could not support life. I have no idea how anyone knows this, from what I know of physical chemistry and such, calculating all the consequences of a hypothetical set of laws of physics greatly exceeds the computing capacity of any computer on Earth, we can’t even do that for the actual laws of physics. But forget that. The next claim is that the probability of these constants being what they are is one in something followed by billions upon billions of zeroes. How do they calculate this? It’s not as if we can say, “we’ve surveyed a billion universes, and only two had life, so the odds of a universe containing life are one in 500 million.” I don’t even know what the numbers are supposed to mean. And yes, though I’m not a physicist, there are physicists who have come out and said, frankly, that the numbers are nonsense. Without the probability claim, we’ve just got the idea that the laws of physics might have been different. But this is true no matter what science finds. And it gives us no reason to believe in God: he too, might not have existed, assuming no good reason to take the idea that God exists necessarily seriously. The argument’s no good.

Another example: biochemist Michael Behe has claimed that there are some systems in biology that are “irreducibly complex.” They need all their parts to function, therefore, they could not have been built up one part at a time, as evolution requires. However, it might be that the parts originally served some other function. Or that in the original version, not all parts were necessary. If you look at Behe’s earliest writings on the subject, he seems to concede this point, mentioning the possibility of an “indirect, circuitous route” producing his “irreducibly complex” structures. He dismisses this possibility, though, as too improbable. However, he doesn’t back this probability claim up with any rigorous analysis. It turns out that when you consider molecular biology, the “indirect, circuitous route” makes a lot of sense: why build everything from scratch? Why not work with what you’ve got? Furthermore, there’s a lot of evidence that this is what’s happened in cases where Behe claimed evolution could not have produced the given feature.

The most respectable approach to probability arguments is called the “Bayesian” approach, after a guy named Thomas Bayes who did important work in probability theory. The idea is this: consider an observation. Consider the hypotheses that might lead to it. If one hypothesis makes the observation significantly more likely, it’s favored by the observation. To see this, imagine you have two urns filled with black and white balls. One urn is mostly white, the other mostly black. You draw a few balls, they’re all white. This doesn’t prove the mostly-white urn is what you’re dealing with, but it does support that suggestion. There are questions about how we can transfer this to actual scientific hypotheses, where the case isn’t so clear-cut, but it seems like at least a good approximate model.

With this approach, I’ve already mentioned the issue of how you calculate the probability of something existing, without God. But there’s also a problem of calculating the probability of how things are given God. Even if God was dead-set on creating some kind of life, why did He make it one way, rather than some other way? Take the case of physical laws: is there any reason to think God would be inclined to make life dependent on a finely-tuned set of physical constants, rather than coming up with a way around that? He’s omnipotent after all. If there’s no reason for him to create such a system of constants, its hard to see how observing it is evidence of God.

Two other ways of setting up probabilistic arguments from design come from the philosopher William Dembski. The first is called the explanatory filter: first you consider chance, if that’s too improbable, you consider physical necessity, if that doesn’t work, you conclude it must be design. The second is “specified complexity,” which Dembski defines as fitting “a highly improbable, independently given pattern.” Dembski claims this is always indicative of design.

I’m sorry to say I’m at a loss to understand why he thinks these are good arguments from design. Both simply try to write evolution by natural selection out of the picture before the debate has even begun. In the explanatory filter, natural selection, as I said before, isn’t pure chance, and it isn’t quite a matter of physical necessity. It’s a fourth option. Similarly, it seems at first glance that natural selection provides an alternative way of producing specified complexity.

Insofar as I understand him, Dembski’s response to these criticisms seems to be that in natural selection, no new information is really generated, it in reality has to be provided by the outside environment. So that environment needs explaining. I find the basic claim dubious, but ignoring that, look at what Dembski’s doing: you explain one thing, and he asks for an explanation of another thing. I suspect he would keep playing that game as long as anyone will go on trying to provide explanations, until they admit that God did it. But how do you explain God? Here, we’ve lost the advantages that the argument from design is supposed to have, we’re back to the crude cosmological argument. The ability to ask “why, why, why” all the time doesn’t prove the existence of God.

Questions?

Online resources:
*http://www.talkorigins.org/ (Very good resource on what evolution is, the evidence for it, and concise refutations of countless anti-evolution arguments.)
*http://www.nsceweb.org/ (Website of the National Center for Science Education, a further resource for critiques of anti-evolution arguments.)
*http://www.arn.org/authors.htm (Lots of articles by big players in the evolution controversy, mostly but not entirely anti-evolution, including Dembski and Behe.)
*http://www.stephenjaygould.org/library/gould_fact-and-theory.html (The essay by Stephen Jay Gould I quoted above.)

Dan Dennett’s bibliography of books on evolution (from /Breaking The Spell/):
*Robert Pennock, /Tower of Babel/
*Mark Perakh, /Unintelligent Design/
*Neil Shanks, /God, the Devil, and Darwin/
*Matt Young and Taner Edis, /Why Intelligent Design Fails/
*National Academy of Sciences, /Science and Creationism/
*Andres Moya and Enrique Font, /Evolution: From Molecules to Ecosystems/
*Mark Pagel, ed., /The Encyclopedia of Evolution/
*Purves et al., /Life: The Science of Biology/

Other pro-evolution books:
*Niles Eldredge, /The Triumph of Evolution: And The Failure of Creationism/
*Philip Kitcher, /Abusing Science: The Case Against Creationism/
*Richard Dawkins, /The Blind Watchmaker/
*Richard Dawkins, /The Ancestors Tale/ (Warning: this is if you want something BIG, but still at the popular level.)

Finally, I should mention Lee Strobel’s /The Case for a Creator/ as a concise, popular summary of the views of the main people in the anti-evolution movement, though NOT one that can always be trusted to accurately present the views of mainstream scientists.