How Do You Spot A Bad Scientific Argument?
August 22, 2006
Anti-evolutionists are skillful at burying the weaknesses of their arguments beneath a wealth of scientific jargon. This presents a problem for fair-minded non-scientists trying to determine where reality lies. If rivals in a debate make differing claims about the relationship between thermodynamics and evolution, for example, how is someone unversed in physics to know who is presenting things accurately?
Sadly, there is no substitute for knowing the subject matter under discussion. If your goal is to understand precisely why creationist arguments are incorrect, you simply have to invest some time studying science in a serious way. For most people, however, such study is impractical. Time issues aside, most scientific disciplines are difficult to learn on one’s own. The result is that many people grow frustrated trying to sort out the various claims and counter-claims made by the two sides.
That’s the bad news. The good news is that much of the creationist fog can be dispersed via some basic understanding of how the scientific community operates. Many, indeed most, anti-evolution arguments should provoke suspicion even among those without training in science. We will consider four indicators which, when present, should strongly suggest you are dealing with a bad scientific argument.
(1) Any argument based on the premise that professional scientists have overlooked an elementary flaw in their theory is almost certainly incorrect.
Evolution has been the cornerstone of biological research ever since Darwin published On the Origin of Species in 1859. That does not mean the theory is necessarily correct, but it does count for something. It means that evolution is not a crazy idea. It will not be overturned by a simple argument that could be explained to a high school student.
A standard example is the argument that natural selection is merely a tautology. Here is a typical formulation, from a young-Earth creationist book:
Schutzenberger and others have shown the above Neodarwinan approach to biogenesis and the origin of species to be tautological, i.e. meaningless. The reasoning behind Schutzenberger’s claim is quite elementary in reality, for he points out that the Neodarwinian hypothesis simply states nothing more than that the organism which survives has survived. Or put otherwise: the organism leaving the greatest number of offspring behind will survive. This type of depth of wisdom is not very difficult to plumb.
(A.E. Wilder Smith, The Natural Sciences Know Nothing of Evolution, 1981, pp. 127).
In a previous essay in this series I explained why this argument is incorrect (and provided other examples of anti-evolutionists raising the issue). But of relevance here is the extreme simplicity of the argument. If Wilder-Smith is correct, then many generations of scientists have simply overlooked that the central concept of their theory has no substance at all. Is that plausible? You do not need to know the details of how biologists define the term “fitness” to reply that it is not.
The oft-repeated claim that evolution runs afoul of the second law of thermodynamics provides a second example:
The discovery that life on Earth developed through evolutionary “steps,” coupled with the observation that mutations and natural selection — like other natural forces — can cause (minor) change, is widely accepted in the scientific world as proof that natural selection — alone among all natural forces — can create order out of disorder, and even design human brains with human consciousness. Only the layman seems to see the problem with this logic. In a recent Mathematical Intelligencer article ("A Mathematician’s View of Evolution,” 22, number 4, 5-7, 2000), after outlining the specific reasons why it is not reasonable to attribute the major steps in the development of life to natural selection, I asserted that the idea that the four fundamental forces of physics alone could rearrange the fundamental particles of nature into spaceships, nuclear power plants, and computers, connected to laser printers, CRTs, keyboards and the Internet, appears to violate the second law of thermodynamics in a spectacular way.
(Granville Sewell, “Evolution’s Thermodynamic Failure,” The American Spectator, 2005).
A proper understanding of the second law of thermodynamics makes it clear that Sewell’s argument is utterly mistaken. But even without that understanding we should be highly suspicious of the claim that non-scientists are capable of spotting a fallacy that has eluded professional scientists. Indeed, as long as you are aware that the second law was formulated well before Darwin published his work, you know enough to realize that Sewell’s argument is highly unlikely to be correct. It is not reasonable that for more than a century scientists have not noticed a simple contradiction between biology and physics.
As a final example, consider Michael Behe’s argument concerning irreducible complexity. He asks, “What type of biological system could not be formed by ‘numerous, successive, slight modifications'?” and answers:
Well, for starters, a system that is irreducible complex. By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system, because any precursor to an irreducibly complex system that is missing a part is by definition nonfunctional. An irreducibly complex biological system, if there is such a thing, would be a powerful challenge to Darwinian evolution.
(Michael Behe, Darwin’s Black Box, pp. 39)
If Behe is correct, then there is a simple test that can show with near certainty that a given biological system could not have evolved gradually via natural selection. Moreover, there are, according to him, numerous systems that satisfy this test. I ask again, is that plausible? Could scientists really have failed to notice so simple a criterion? Or is it more likely that there is a flaw in Behe’s logic?
(2) Any assertion that anti-evolutionists cannot get a fair hearing because the scientific community conspires to suppress their views can be dismissed out of hand.
The point here is not that scientists are so single-mindedly devoted to the truth that they would never behave in such a manner (though, as it happens, most of them would not). Rather, it is that scientists would be unable to suppress a powerful idea even if they wanted to. You see, what we refer to loosely as “the scientific community” is really just a collection of thousands of individual scientists. Each of these scientists carries out his research hoping to make a lasting contribution to our understanding of nature. And the surest way to make such a contribution is to show that a mainstream bit of orthodoxy is actually incorrect.
Scientists disseminate their work through scientific journals, and here we have a second layer of protection from conspiracies against unpopular ideas. There are hundreds of scientific journals, and they operate independently of one another. They must compete with each other for the attention of scientists. Consequently, every journal wants to be the one that publishes the next big breakthrough.
The Darwinian theory of evolution has been such a staple of biology for so long that every scientist would like to be the one to bring it down. And every journal would like to be the one that publishes the seminal paper in that regard. Both of these factors would make it impossible to squelch the arguments of anti-evolutionists, if those arguments had any scientific merit.
Here is a standard example of this sort of argument:
As we saw in Kevin Padian’s “cracked kettle” approach to biology, dogmatic Darwinists begin by imposing a narrow interpretation on the evidence and declaring it to be the only way to do science. Critics are then labeled unscientific; their articles are rejected by mainstream journals, whose editorial boards are dominated by the dogmatists; the critics are denied funding by government agencies, who send grant proposals to the dogmatists for “peer” review; and eventually the critics are hounded out of the scientific community altogether.
In the process, evidence against the Darwinian view simply disappears, like witnesses against the Mob. Or the evidence is buried in specialized publications, where only a dedicated researcher can find it. Once critics have been silenced and counter-evidence has been buried, the dogmatists announce that there is no scientific debate about their theory, and no evidence against it. Using such tactics, defenders of Darwinian orthodoxy have managed to establish a near-monopoly over research grants, faculty appointments, and peer-reviewed journals in the United States.
(Jonathan Wells, Icons of Evolution, pp. 235-236).
If there were only one journal and only one grant-funding agency, we might be able to take this argument seriously. In reality, however, the sheer scope of the conspiracy Wells is alleging rules it out of all serious consideration. Every major scientific organization that has taken a stand on this issue has come out in support of evolution. Not one wishes to align itself with the creationists or the ID folks. Are all of them in the hands of dogmatic evolutionists? Hundreds of scientific journals turn out tens of thousands of papers related to evolution each year, compared to almost none for ID (and the handful of papers ID folks claim in support of their view are highly debatable, to put it kindly). All of those editorial boards and all of those peer-reviewers are blinded by ideology? It is not credible.
Which does not stop the creationists and ID folks from repeating the charge:
In the final analysis, it is not any specific scientific evidence that convinces me that Darwinism is a pseudoscience that will collapse once it becomes possible for critics to get a fair hearing. It is the way the Darwinists argue their case that makes it apparent that they are afraid to encounter the best arguments against their theory. A real science does not employ propaganda and legal barriers to prevent relevant questions from being asked, nor does it rely on enforcing rules of reasoning that allow no alternative to the official story. If the Darwinists had a good case to make, they would welcome the critics to an academic forum for open debate, and they would want to confront the best critical arguments rather than to caricature them as straw men. Instead they have chosen to rely on the dishonorable methods of power politics.
(Phillip Johnson, The Wedge of Truth, pp. 141)
Perhaps. Or maybe scientists have, indeed, given fair consideration to anti-evolution arguments, and have simply found them wanting. You decide which is more likely.
(3) Any argument based on the premise of major conceptual holes in evolutionary theory should be rejected.
It is sometimes said that in science there are two sorts of open questions. There are problems, and then there are mysteries. A problem is a situation that is likely to be resolved via more research of the sort scientists are currently doing. A mystery, by contrast, is a question that seems unanswerable within the confines of current theorizing.
Evolutionary biology has numerous problems. That, after all, is why people continue to do research in the area. It is a difficult practical problem to determine the precise evolutionary relationships between modern organisms or to unravel the early stages of a complex adaptation. But many questions of this sort have been answered in the past, and there is every reason for optimism that the methods that have worked for so long will continue to bear fruit.
But there are no mysteries in evolution. By this I mean that there are currently no bits of empirical evidence that seem utterly inexplicable from an evolutionary viewpoint. This is unsurprising. Evolution has been mainstream biology for over a century. It would not have earned that status if it were unable to answer important fundamental questions.
With that in mind, it becomes easier to assess statements like this:
The impotence of Darwinian theory in accounting for the molecular basis of life is evident not only from the analyses in this book, but also from the complete absence in the professional scientific literature of any detailed models by which complex biochemical systems could have been produced, as shown in Chapter 8. In the face of the enormous complexity of that modern biochemistry has uncovered in the cell, the scientific community is paralyzed. No one at Harvard University, no one at the National Institutes of Health, no member of the National Academy of Sciences, no Nobel prize winner - no one at all can give a detailed account of how the cilium, or vision, or blood clotting, or any complex biochemical process might have developed in a Darwinian fashion.
(Michael Behe, Darwin’s Black Box, pp. 187)
If you happen to be familiar with the scientific literature on molecular evolution, then you know that Behe’s assertion here is not correct. But even without such familiarity there is good reason to be suspicious of this claim. Explaining the formation of complex systems is one of the primary tasks facing any theory of evolution. If it were really true that after a century of research the scientific community remained “paralyzed” by such complexity, then Darwinism would have been discarded long ago.
Others are even more audacious than Behe:
Indeed, the following problems have proven utterly intractable not only for the Darwinian selection mechanism, but also for any other undirected natural process proposed to date: the origin of life, the origin of the genetic code, the origin of multicellular life, the origin of sexual reproduction, the scarcity of transitional forms in the fossil record, the biological Big Bang that occurred in the Cambrian era, the development of complex organ systems and the formation of irreducibly complex molecular machines. These are just a few of the more serious difficulties that confront every theory of biological evolution that posits only undirected natural processes.
(William Dembski, No Free Lunch, pp. 247).
A detailed discussion of each of the points Dembski raises would take many pages indeed. Such discussions are readily available, in books and on the internet, for those with the patience to slog through them. In the meantime, however, I would ask you simply to note that Dembski is suggesting that evolution is helpless before most of the major questions it is called upon to address. Accepting his claim requires you to believe that scientists have clung to this theory for more than a century in spite of this impotence. Does that seem likely? Or is it more likely that Dembski’s list is mere rhetoric intended to discredit a theory whose conclusions he finds objectionable?
(4) Any assertion to the effect that scholars from fields other than biology are better placed to see the flaws in evolution than are biologists themselves should be disregarded.
Biologists are nearly unanimous in the view that common descent is real, and that natural selection is the primary mechanism guiding the pattern of that descent. This presents a serious problem for creationists and ID folks. Since there are few professional biologists willing to be numbered among them, they must persuade people that expert commentary on the minutiae of this subject is best obtained from people outside biology. And that leads them to make statements like this:
Before undertaking this task I should say something about my qualifications and purpose. I am not a scientist but an academic lawyer by profession, with a specialty in analyzing the logic of arguments and identifying the assumptions that lie behind those arguments. This background is more appropriate than one might think, because what people believe about evolution and Darwinism depends very heavily on the kind of logic they employ and the kind of assumptions they make. Being a scientist is not necessarily an advantage when dealing with a broad topic like evolution, which cuts across many scientific disciplines and also involves issues of philosophy. Practicing scientists are of necessity highly specialized, and a scientist outside his field is just another layman.
(Phillip Johnson, Darwin on Trial, pp. 13)
That this is absurd follows from a basic consideration of how scientists approach their work. Scientists accept evolution because they can see the tangible dividends it pays in their research. Evolution is, among other things, a tool that is used by biologist to make sense of the data they collect in the field and the lab. It is not the end result of an abstract process of logical reasoning from a controversial starting point.
Furthermore, as previously noted, it is not credible to suggest that the overwhelming support for evolution among scientists is the result of their inability to spot elementary logical fallacies or hidden assumptions.
Let us close with one further example:
The other point is very simple, but also seems to be appreciated only by more mathematically-oriented people. It is that to attribute the development of life on Earth to natural selection is to assign to it—and to it alone, of all known natural “forces"—the ability to violate the second law of thermodynamics and to cause order to arise from disorder.
(Granville Sewell, “A Mathematician’s View of Evolution,” The Mathematical Intelligencer, 2000).
We have already discussed, under point number one, why the second law argument can be rejected out of hand. What is interesting here, however, is the suggestion that “more mathematically-oriented people” can see a fallacy in evolutionary thinking that professional biologists are blind to. Needless to say, a biologist claiming that his training in the life sciences allows him to see errors in current mathematical practice of which mathematicians themselves are unaware would not be taken seriously. The argument does not improve by being turned around.
Sorting through the various arguments in the evolution/creationism dispute can be a daunting and impractical task. But if you are willing to grant certain reasonable assumptions about the scientific community in general, and biologists in particular, then much of the difficulty goes away.
Professional scientists are highly competant and work under a system that makes censorship virtually impossible. They are not going to be systematically guilty of crude errors in logic, and they are not going to base their research on a theory that has no answers to the fundamental questions that are put to it. And the details of given scientific topics are best understood and assessed by the people working in that area, and not by outsiders with axes to grind. Grant these assumptions, and virtually everything anti-evolutionists say provokes deep suspicion.
And if you reject these assumptions? Well, then I suspect you have issues with science unrelated to the merits of evolutionary theory.