By William A. Dembski
A decade ago, Phillip Johnson used to boil down his critique of evolution to analyzing three words: science, evolution, and creation. According to Johnson, by suitably equivocating over the meaning of these words, Darwinists were able to confuse the public and themselves into consenting to a theory that ordinary standards of evidence rendered completely absurd.
The debate has progressed considerably since the early 1990s when Johnson mainly focused on critiquing evolution. Intelligent design (ID) now offers a positive alternative to conventional evolutionary theory. I therefore propose that we add two words to Johnson's list: design and nature.
Darwinists have a long history of evading critical scrutiny. To interrogate Darwinists with the aim of opening up discussion about evolution in the public square (e.g., discussing its strengths, weaknesses, and alternatives in the high school biology curriculum), I therefore propose subjecting them to a sustained line of questioning about what they mean by each of these five terms: science, nature, creation, design, and evolution.
Accordingly, the Vise Strategy consists in subjecting Darwinists to a sustained line of questioning about these five key terms in settings where they have no choice but to answer the questions (as in a legal deposition). Hence the "vise" metaphor. The aim of this line of questioning is to make clear to those reading or hearing the Darwinists' answers that their defense of evolution and opposition to ID are prejudicial, self-contradictory, ideologically driven, and above all unjustifiable on the basis of the underlying science. Here are the questions:
Is it fair to say that you regard intelligent design as not a part of science? Would you agree that proponents of intelligent design who characterize it as a "scientific discipline" or as a "scientific theory" are mistaken?
Would you characterize intelligent design as a "pseudoscience"?
Would it be fair to say that, in your view, what makes intelligent design a pseudoscience is that it is religion masquerading as science? If ID is something other than science, what exactly is it?
Are you a scientist?
Do you feel qualified to assess whether something is or is not properly a part of science? What are your qualifications in this regard? [Take your time here.]
Do you think that simply by being a scientist, you are qualified to assess whether something is or is not properly a part of science?
Have you read any books on the history and philosophy of science
[If yes:] Which ones? [e.g., Herbert Butterfield, Ronald Numbers, Thomas Kuhn]
Would you agree that in the history of science, ideas that started out as "pseudoscientific" may eventually become properly scientific, for example, the transformation of alchemy into chemistry?
Is it possible that ID could fall in this category, as the transformation into a rigorous science of something that in the past was not regarded as properly scientific? [If no, return to this point later.]
Are there precise criteria that tell you what belongs to science and what doesn't?
[If no:] Then on what basis do you preclude ID from being science? In that case, isn't your exclusion of ID from science purely a subjective judgment? How do you rule it out as non-science if you have no criteria for judging what's in and what's outside of science?
Please list all the criteria you can think of that demarcate science from non-science. [Take your time with this.] Are you sure these are all of them? If you are not sure these are all of them, how can you be sure that your criteria are the right ones?
Do these criteria work in all cases? Do they tell you in every instance what's in and what's outside of science? Are there no exceptions?
[If yes:] Tell me about the exceptions? [After several of them:] Are there any more exceptions? Is that everything? [Take your time with this.]
Let's consider one very commonly accepted criterion for what's in and what's outside of science, namely, testability. Would you say that testability is a criterion for demarcating science? In other words, if a claim isn't testable, then it's not scientific? Would you agree with this?
Would you give as one of the reasons that ID is not science that it is untestable? [Return to this.]
Let's stay with testability for a bit. You've agreed that if something is not testable, then it does not properly belong to science. Is that right?
Have you heard of the term "methodological materialism" (also sometimes called "methodological naturalism")?
Do you regard methodological materialism as a regulative principle for science? In other words, do you believe that science should be limited to offering only materialistic explanations of natural phenomena?
[If you experience resistance to this last question because the Darwinist being interrogated doesn't like the connotations associated with "materialism" try:]
This is not a trick question. By materialistic explanations I simply mean explanations that appeal only to matter, energy, and their interactions as governed by the laws of physics and chemistry. Do you regard methodological materialism in this sense as a regulative principle for science? [It's important here to get the Darwinist to admit to methodological materialism — this is usually not a problem; indeed, usually they are happy to embrace it:]
Could you explain the scientific status of methodological materialism? For instance, you stated that testability is a criterion for true science. Is there any scientific experiment that tests methodological materialism? Can you describe such an experiment?
Are there theoretical reasons from science for accepting methodological materialism? For instance, we know on the basis of the second law of thermodynamics that the search for perpetual motion machines cannot succeed. Are there any theoretical reasons for thinking that scientific inquiries that veer outside the strictures of methodological materialism cannot succeed? Can you think of any such reasons?
A compelling reason for holding to methodological materialism would be if it could be demonstrated conclusively that all natural phenomena invariably submit to materialistic explanations. Is there any such demonstration?
[Suppose here the success of evolutionary theory is invoked to justify methodological materialism — i.e., so many natural phenomena have submitted successfully to materialistic explanation that it constitutes a good rule of thumb/working hypothesis. In that case we ask:]
But wouldn't you agree that there are many natural phenomena for which we haven't a clue how they can be accounted for in terms of materialistic explanation? Take the origin of life? Isn't the origin of life a wide open problem for biology, one which gives no indication of submitting to materialistic explanation.
[If they claim that it isn't an open problem, continue:]
Are you claiming that the problem of life's origin has been given a successful materialistic explanation? If so, please state the "theory of life's origin" comparable to the neo-Darwinian theory for biological evolution. Can you sketch this widely accepted theory of life's origin? How does it account for the origin of biomacromolecules in the absence of the biosynthetic machinery that runs all contemporary living cells? Furthermore, how does such a theory provide a materialistic explanation for how these biomacromolecules came together and organized themselves into a living cell in the first place?
Would you agree, then, that methodological materialism is not scientifically testable, that there is no way to confirm it scientifically, and therefore that it is not a scientific claim? Oh, you think it can be confirmed scientifically? Please explain exactly how is it confirmed scientifically? I'm sorry, but pointing to the success of materialistic explanations in science won't work here because the issue with materialistic explanations is not their success in certain cases but their success across the board. Is there any way to show scientifically that materialistic explanations provide a true account for all natural phenomena? Is it possible that the best materialistic explanation of a natural phenomenon is not the true explanation? If this is not possible, please explain why not. [Keep hammering away at these questions until you get a full concession that methodological naturalism is not testable and cannot be confirmed scientifically.]
Since methodological materialism is not a scientific claim, what is its force as a rule for science? Why should scientists adopt it? [The usual answer here is "the success of science."]
But if methodological materialism's authority as a rule for science derives from its success in guiding scientific inquiry, wouldn't it be safe to say that it is merely a working hypothesis for science? And as a working hypothesis, aren't scientists free to discard it when they find that it "no longer works"?
It's sometimes claimed that the majority of scientists have adopted methodological materialism as a working hypothesis. But have all scientists adopted it? Is science governed by majority rule?
If [as the Darwinist interrogatee will by now hopefully have admitted] methodological materialism is not a scientific claim, how can it be unscientific for ID theorists to discard it as a working hypothesis for science? In the absence of methodological materialism as a regulative principle for science, what else is there that might prevent ID from being developed into a full-fledged science? You claimed earlier that ID is not testable. Is that the reason you think ID cannot be developed into a full-fledged science?
But how can you say that ID is not testable. Over and over again, Darwin in his Origin of Species compared the ability of his theory to explain biological data with the ability of a design hypothesis to explain those same data. Moreover, Darwin stressed in the Origin that "a fair result can be obtained only by fully stating and balancing the facts and arguments on both sides of each question." How, then, can you say that ID is not testable when Darwin clearly claimed to be simultaneously testing a design hypothesis against his own theory?
Let's talk about creation and creationism a bit. Is it fair to say that you think ID is a form of creationism? Why do you think that?
Does ID try to harmonize its scientific claims with the Bible? If so, please indicate.
Is it fair to say that ID is not in the business of matching up its scientific claims with the Genesis record of creation or any other system of religious belief? If otherwise, please indicate.
Is it fair to say that ID is not young earth creationism, also known as scientific creationism or creation science? [The important thing with this line of questioning is to get the Darwinist to agree that ID is not creationism in any conventional sense.]
Is it possible to hold to ID and not be a Christian, Jew, or Muslim? Is it possible to be a Buddhist and hold to ID? Is it possible to be a Hindu and hold to ID? [The answer in all these cases is yes and there are respected scientists from all these systems of religious belief who hold to ID.]
Is it possible to hold to ID for philosophical reasons that have nothing to do with conventional belief in God? In other words, can one hold to ID and not believe in God, much less a creator God
Would you agree that Aristotle, who held to an eternal universe and an inherent purposiveness within nature (i.e., a purposiveness not imposed on nature from the outside), did not have a conventional belief in God but would today properly be regarded as an ID advocate? Are you familiar with Antony Flew's recent embrace of intelligent design despite his rejection of conventional belief in God (for instance, he explicitly rejects personal immortality)?
Your main beef with ID therefore seems to be not that it holds to a religious doctrine of creation but rather that it takes material causation to be an incomplete category of scientific explanation. Is that true or is there any other criticism that you think is more significant? If it is true, how can you claim that ID is creationism? Creationism suggests some positive account of an intelligence creating the world. But your problem with ID seems to be its denial that a certain category of causation can account for everything in nature?
Are you merely a methodological materialist or are you also a metaphysical/philosophical materialist? In other words, do you pretend that everything happens by material causation merely for the sake of science, but then bracket that assumption in other areas of your life (say on Sundays when you go to church)? Or do you really hold that everything happens by material causation — period? If the latter, on what grounds do you hold to metaphysical materialism? Can that position be scientifically justified? How so? If you claim merely to be a methodological materialist, then whence the confidence that material causation is adequate for science? [This cycles back to previous questions.]
What is the nature of nature? Does nature operate purely by material causation. If not, how could we know it?
Consider the following riddle (posed by Robert Pennock): "If you call a tail a leg, how many legs does a dog have?" Wouldn't you agree that the answer is four: calling a tail a leg doesn't make it one. Accordingly, wouldn't it be prejudicial to define nature as a closed system of material entities in which everything happens by material causation? Wouldn't you agree that nature is what nature is, and it is not the business of scientists to prescribe what nature is like in advance of actually investigating nature?
Let's return to the issue of testability in science? Do you agree that for a proposition to be scientific it must be testable? Good.
Would you agree, further, that testability is not necessarily an all-or-none affair? In other words, would you agree that testability is concerned with confirmation and disconfirmation, and that these come in degrees, so that it makes sense to talk about the degree to which a proposition is tested? For instance, in testing whether a coin is fair, would finding that the coin landed heads twenty times in a row more strongly disconfirm the coin's fairness than finding that it landed only ten heads in a row? [Keep hammering on this until there's an admission that testing can come in degrees. Examples from the history of science can be introduced here as well.]
Okay, so we're agreed that science is about testable propositions and that testability of these propositions can come in degrees. Now, let me ask you this: Is testability symmetric? In other words, if a proposition is testable, is its negation also testable? For instance, consider the proposition "it's raining outside." The negation of that proposition is the proposition "it's not the case that it's raining outside" (typically abbreviated "it's not raining outside" — logicians form the negation of a proposition by putting "it's not the case that …" in front of a proposition). Given that the proposition "it's raining outside" is testable, is it also the case that the negation of that proposition is testable?
As a general rule, if a proposition is testable, isn't its negation also testable? [If you don't get a firm yes to this, continue as follows:] Can you help me to understand how a proposition can be testable, but its negation not be testable? To say that a proposition is testable is to say that it can be placed in empirical harm's way — that it might be wrong and that this wrongness may be confirmed through empirical data, wouldn't you agree? Testability means that the proposition can be put to a test and if it fails the test, then it loses credibility and its negation gains in credibility?Wouldn't you agree? [Keep hammering on this until you've gotten full submission.]
Doesn't it then follow that whenever a proposition is testable, so is its negation, with a test for one posing a test also for the other?
Let me therefore ask you, are the following propositions scientific and, as a consequence, testable: (1) Humans and other primates share a common ancestor. (2) All organisms on Earth share a common ancestor. (3) Life on Earth arose by material causes. Are the negations of these propositions therefore scientific and testable? If not, why not?
Let's focus on the third of these propositions, namely, that life arose by purely material causes. How is it tested? How would its negation be tested? If its negation is not testable, how can the original proposition be testable? Wouldn't it then be just like arithmetic — simply a necessary truth and not something in contact with empirical data?
Let's now turn to evolution. Back in 1989 Richard Dawkins remarked that those who don't hold to evolution are "ignorant, stupid or insane (or wicked, but I'd rather not consider that)." Is Dawkins right?
Evolutionists distinguish between common descent (also known as universal common ancestry) and the mechanisms of evolution. Common descent is a historical claim. It says that all organisms trace their lineage back to a last universal common ancestor (sometimes abbreviated LUCA). Do you hold to common descent? Why? Please be as detailed as you can in describing the scientific evidence that leads you to that belief.
No doubt you have heard of the Cambrian explosion. Isn't it the case that fossil evidence reveals most extant animal phyla first appear over a period of 5 to 10 million years in the Cambrian rocks without evident precursors?
Consider an octopus, a starfish, an insect, and a fish. To what phyla do these belong? Is there solid fossil evidence that these share a common ancestor? If so, please provide the details. [Watch for a snow job; no compelling evidence exists.]
Do you regard the Cambrian explosion as providing a challenge to common descent? If not, why not?
Let's turn next to the mechanisms of evolution. What are the mechanisms of evolution? [Get as many out of the evolutionist as possible. Natural selection and random mutation will be at the top of the list, with genetic drift, lateral gene transfer, and developmental factors also receiving mention.] Are these all of them? [Take your time. Wait until the Darwinist admits that these are all he/she can think of.]
So, you're not sure that these are all the mechanisms that drive the process of biological evolution. Is intelligence a mechanism? If you can't be sure that you've got all the relevant mechanisms of evolution, how can you rule out intelligence as a factor in biological evolution?
Okay, you're convinced that the neo-Darwinian mechanism of natural selection and random genetic change is the most important factor in biological evolution. Why is that? What is the evidence that it deserves this place in evolutionary theorizing?
Are you familiar with the molecular machines that are in all cells and without which cellular life would be impossible (the one that has been most discussed is the bacterial flagellum, a miniature bidirectional motor-driven propeller that moves certain bacteria through their watery environments)?
Are you familiar with the writings of James Shapiro (who is on faculty at the University of Chicago) and Franklin Harold (who is an emeritus professor at Colorado State University)? Shapiro is a molecular biologist, Harold a cell biologist. They both claim that there are no detailed Darwinian accounts for the evolution of molecular machines like the flagellum. Do you agree with their assessment? Are there any other evolutionary mechanisms that yield a detailed, testable scenario for the origin of such molecular machines?
Theodosius Dobzhansky, one of the founders of the neo-Darwinian synthesis remarked toward the end of his life that nothing in biology makes sense except in the light of evolution. Do you accept this statement?
But isn't it the case that for systems like the bacterial flagellum, evolutionary biology has no clue how they came about? [If the Darwinist balks, keep pressing for detailed evolutionary accounts of such complex molecular machines.] So, was Dobzhansky wrong?
Earlier you expressed reservations about ID being testable? Do you also share such reservations about the testability of evolutionary theory? No? Could you explain how evolutionary theory is testable? What sort of evidence would count against evolutionary theory?
The evolutionist J. B. S. Haldane once remarked that what would convince him that evolutionary theory was wrong was finding a rabbit fossil in Precambrian rocks. Would such a finding convince you that evolutionary theory is wrong? And wrong in what sense? Would it show that common descent is wrong? If such a fossil were found in Precambrian rocks, why not simply explain it as an evolutionary convergence?
Suppose, for the sake of argument, we accept common descent. In that case, why should we believe that natural selection and random genetic change are the principle mechanisms driving biological evolution? Is that claim testable?
Do you accept that there are other mechanisms involved in biological evolution besides natural selection and random genetic change? If so, how do biologists know that the totality of these mechanisms account for all of biological complexity and diversity? Is the claim that these mechanisms account for all of biological complexity and diversity itself testable? Have you tested it? How so? How can it be tested? If it should be tested and disconfirmed (as can always happen to testable propositions), then what is the alternative hypothesis that correspondingly is confirmed? Wouldn't it have to be a design hypothesis? If not, why not?