Skip navigation.
The Critic's Resource on AntiEvolution

Dembski's "intelligent design" questions for teachers: Answered

William A. Dembski has a number of questions that he'd like to have students pose to their teachers. These questions quoted from Dembski are rendered in italics.

Here are some answers for the teachers to give their students in reply.

1. DESIGN DETECTION. If the universe, or some aspect of it, is intelligently designed, how could we know it? Do reliable methods for detecting design exist? What are they? Are such methods employed in forensics, archeology, and data fraud analysis? Could they conceivably detect design in biological systems?

A. We know about "design" because of our prior experience. Our appreciation of "design" comes about through an inductive process, as David Hume noted over two centuries ago. Nothing so far discovered by science has changed this. Scientists have developed a number of techniques and protocols to aid them in distinguishing artifacts that have been made by humans and other animals from things that have simply weathered or been subject to some non-volitional process. These techniques, however, have had nothing to do with conjectures posed by "intelligent design" advocates. Humans who alter the genetic information of bacteria and other organisms sometimes patent the exact changes made. Matching the genetic information in an organism to the changed genetic sequences would establish that the organism inherited that information from such an altered source. Again, this sort of process is not based upon and has not benefited from work done by "intelligent design"

Additional reading: The advantages of theft over toil, an article that clearly lays out problems in the sort of procedure that is common to "intelligent design" approaches to "detecting design". Information Theory, Evolutionary Computation, and Dembski's "Complex Specified Information" is an in-depth analysis of the claims that Dembski made concerning "design detection" up through 2003. There are also chapters devoted to this topic in Mark Perakh's Unintelligent Design and the anthology edited by Matt Young and Taner Edis, Why Intelligent Design Fails.

2. RELEVANCE OF SETI. The search for extraterrestrial intelligence (SETI) is a scientific research program that searches for signs of non-human intelligence from distant space. Should biologists likewise search for signs of non-human intelligence in biological systems? Why or why not?

A. SETI is a good example of scientific approaches to "detecting design". SETI works precisely by taking information from human experience and using that to help decide what would constitute a signal that would indicate the existence of a non-human extra-terrestrial intelligence. SETI does not use procedures such as those talked about by "intelligent design" advocates. Instead, SETI looks for narrowband radio sources, the sort of radio sources that humans would build if we decided to send a radio message to other intelligent beings in space. This has nothing to do with the content that may be broadcast in such a signal, but rather this distinguishes a manufactured radio source from natural radio sources, which typically are spread over many frequencies. Most biological systems do not produce appreciable radio waves, and certainly not narrowband signals of the sort that the SETI project looks for.

Additional reading: SETI Project FAQ that notes the search for narrowband carriers, and that their current equipment is not even capable of recording signal content.

3. BIOLOGY'S INFORMATION PROBLEM. What explains the origin of complex information-rich patterns in biological systems? Could biological systems exhibit informational patterns that cannot be adequately be explained by natural selection and other material mechanisms? What would such patterns look like?

A. So far, no inadequacy has been identified in the processes of evolutionary biology to account for biological phenomena. It is our uniform experience that for every biological system for which we have good data concerning its origin, there is a plausible, widely-accepted scientific explanation using the concepts and processes of evolutionary biology. "Intelligent design" advocates always use as examples those systems which have been little studied so far, or for which there is little possibility that future research will dramatically improve the quantity and quality of the data bearing upon its origin, and they have so far ignored biological systems where we have abundant data. Why would people claiming to be doing science fail to apply their ideas to the test of systems that have plentiful data available?

Additional reading: A long article detailing the "intelligent design" argument concerning "the biological information problem" was published in 2004, and immediately attracted criticism because of its poor level of argumentation, misrepresentation of literature, overlooking of relevant literature, and reliance upon negative argument.

4. MOLECULAR MACHINES. Can you give examples of structures in the cell that resemble machines designed by humans? Does the complexity of these molecular machines rival artifactual machines made by humans? Is there any solid evidence that such machines could have arisen apart from actual design?

A. Historically, no such recognition of "machine-like" correspondences goes with the record of progressive discoveries of cell structures and organelles. It is only in retrospect that one finds people using "machine" analogies when discussing cellular features. In other words, humans apply a familiar analogy to biological structures, but that does not mean that the use of the analogy requires that cellular structures be viewed as worked artifacts. There has been no scientific work done that would indicate that evolutionary processes are in principle or in practice inadequate to account for the components of cells called "machine-like" by "intelligent design" advocates.

Additional reading: An attempted critique of the sufficiency of evolutionary processes has itself been criticized.

5. IRREDUCIBLE COMPLEXITY. Are there complex biological systems whose parts are all indispensable for the systems to perform their functions? If so, are such 'irreducibly complex' systems evidence of intelligent design? If not, why not?

A. Evolutionary biologists from 1918 onward have predicted the appearance of features via evolutionary processes that would have the property of brittleness, that all parts of the system are required for a particular function. A number of specific evolutionary processes that can result in systems with "irreducible complexity" have been identified by scientists. Significantly, "intelligent design" advocates have backed away from flat claims of unevolvability and instead now deploy criticisms that attempt to argue that these evolutionary processes must be highly improbable.

Additional reading: In Mark Isaak's index of creationist claims, he notes the history of the idea of what is now called "irreducible complexity", and provides several reasons why this is not a problem for evolutionary biology.

6. REUSABLE PARTS. Human designers reuse designs that work well. Life forms likewise reuse of structures that work well (the camera eye, for example). Is this evidence for common descent, evolutionary convergence, common design, or a combination of these? How do we decide among these options?

A. Because organisms inherit traits from their ancestors, "reuse" of parts is automatically a part of common descent. Population genetics has shown through laboratory work many aspects of the process of inheritance and the mechanisms of evolutionary change. "Intelligent design" advocates make conjectures about "reuse" that would occur through the action of an agent operating over long portions of the history of life on earth, and yet no independent evidence for the existence of such an agent has ever been exposed to scientific scrutiny. Nor have "intelligent design" advocates provided a mechanism for how "reuse" could occur other than ordinary evolutionary descent with modification. In the case of camera eyes, there is evidence of convergence because the histology of the eyes in different lineages shows clear differences, and those differences are consistent with the principle that features that evolve after the divergence of lineages are not shared between those separate lineages. "Reuse" does not explain an existing problem in evolutionary biology, but rather is offered as an unsubstantiated conjecture that has no scientific standing.

7. REVERSE ENGINEERING. In trying to understand biological systems, molecular biologists need to 'reverse engineer' them. In other words, they start with functional biological systems and then use their knowledge of engineering to determine how the systems could have been designed and built. Is this evidence that the systems were engineered to begin with?

A. No. That humans use concepts from engineering to understand biological structures says nothing about how the biological structures came to be. It is a statement about how humans understand the systems, not the systems themselves. We can use engineering concepts to understand natural rock bridges in the southwestern U.S. or the stresses on a tree tha has fallen to lean against another tree, but that doesn't suggest that the natural bridges were "designed" or that the tree didn't fall naturally to lean against its neighbor.

Molecular biologists have done a stunning amount of engineering work, to be sure, but this has been novel work, and has not been broadly informed by prior engineering efforts of humans working at the macro scale. "Intelligent design" advocates utilize what is called equivocation when employing the phrase "reverse engineering" to refer to the work of molecular biologists, because the functions that biological systems meet are not necessarily "engineered" in the same sense we use when we refer to the work of humans.

8. PREDICTIONS. Do intelligent design theory and neo-Darwinian theory make different predictions? Consider, for instance, junk DNA. For which of the two theories would the idea that large stretches of DNA are junk be more plausible? Which theory is more likely to look for unknown uses of seemingly useless biological structures?

A. "Intelligent design" advocates also make use of what is known as "over-qualified" sentences or questions. In this instance, we see that here it is assumed that there is a "theory" of "intelligent design", and yet scientists have not broadly accepted that any such thing exists. There are any number of popular works that make conjectures concerning "intelligent design", but so far there is no scientific theory of "intelligent design". Because there is no "intelligent design theory", the things that are sometimes offered as "predictions" of "intelligent design" uniformly are ad hoc claims that cannot be derived in any principled fashion from an underlying scientific premise, as would be the case if there were such a theory.

So far, every function for DNA sequences, whether expressed or unexpressed, has been identified by practicing biologists in their research, and no research identifying new functions of unexpressed DNA has been published by the "intelligent design" advocates. By our uniform experience, evolutionary biologists deliver scientific knowledge of the functions of DNA, and "intelligent design" advocates do not.

9. FOLLOWING THE EVIDENCE. What evidence would convince you that intelligent design is true and that neo-Darwinism is false? Could such evidence even exist? What would it look like? If no such evidence exists or indeed can exist, how can neo-Darwinism be a testable scientific theory?

A. Whether "intelligent design theory" can be shown to be true is still up in the air, since no intelligent design "theorist" has ever published an actual "intelligent design" theory with any more detail than "This was designed". Furthermore, if no evidence for "intelligent design" exists, it has no effect on whether modern evolutionary theory is testable. This question embodies a fallacious method of argumentation called a false dichotomy, which assumes that only the two possibilities mentioned exist. Modern evolutionary theory is tested hundreds of times a year in hundreds of research papers. "Intelligent design" is tested in none. Evolutionary theory is not tested against intelligent design -- it is tested against systematically gathered data from both the field and the laboratory.

10. IDENTIFYING THE DESIGNER. Can we determine whether an object is designed without knowing anything about its designer? If an unidentified intelligence was responsible for designing biological systems, how could we know it?

A. If the designer is unknown and if we know nothing at all about the designer's knowledge, skills, abilities, intentions, or methods of manufacturing an object, we don't know what to look for. To "detect" design, we must make some hypotheses about what the "designer" could and could not do. Otherwise we're stabbing in the dark. Once again, forensics, archaeology, and data fraud analysis can succeed because we know a lot about human designers and we know what to look for. If we know nothing about a designer of biological structures, we have no idea what to look for.

Dembski refers questioners to a book of his:

See The Design Revolution by William A. Dembski for detailed
background regarding these questions. To order this book or read other articles by William Dembski, visit the Access Research Network website at

But to become informed, one should undertake some additional reading: The design revolution? How William Dembski Is Dodging Questions About Intelligent Design by Mark Perakh, Desperately Evading the Toughest Questions about Intelligent Design: A Review of Dembski's The Design Revolution by Jeffrey Shallit.


Elsberry, Wesley R. and Jeffrey O. Shallit. 2003. Information Theory, Evolutionary Computation, and Dembski's "Complex Specified Information". Online.

Perakh, Mark. 2004. Unintelligent Design. Prometheus Books.

Wilkins, John S, and Wesley R Elsberry. 2001. The advantages of theft over toil: the design inference and arguing from ignorance. Biology and Philosophy 16 (November):711-724.

Young, Matt and Taner Edis (eds.). 2004. Why Intelligent Design Fails. Rutgers University Press.


Mark Isaak's Index of Creationist Claims
An exhaustive listing of antievolution claims, brief responses to those claims, and links to further material.
The TalkOrigins Archive
A award-winning site that provides mainstream science answers to antievolution claims, Frequently Asked Question compilations on topics in evolutionary biology, and the "Fossil Hominids" sub-site.
The Panda's Thumb weblog
A group weblog and the virtual pub of the University of Ediacara.
National Center for Science Education
Non-profit organization that defends the teaching of evolution in the public schools.
Understanding Evolution
A site for teachers and students to learn about the science of evolutionary biology.
The Quixotic Message, or No Free Hunch by Steve Reuland.
A humorous look at the inconsistent messages given by "intelligent design" advocates.

Acknowledgments: This is a collaborative work incorporating ideas and text from Wesley R. Elsberry, Richard B. Hoppe, and Mark Perakh.

IN DEVELOPMENT -- contact Wesley if you would like to contribute to this page.

Appendix: Ten Questions About "Intelligent Design"

Q1. Why do "Intelligent Design" advocates talk about "Intelligent Design theory", but have never actually proposed a theory that passes scientific muster?

Q2. If "Intelligent Design" were true, there should be biological systems that we have a lot of data about their origin and for which we should not find any plausible evolutionary process to explain it. Why have none of these sort of systems been found?

Q3. In the "Intelligent Design" textbook, Of Pandas and People (OPAP), it talks about how transitional fossils in the whale lineage are lacking, and that maybe they never existed. Since OPAP was published, many whale fossils have been found that fill in the periods in question. Why should we consider the current claims of "Intelligent Design" advocates to be any more reliable than the claim about fossil whales in OPAP?

Q4. If "Intelligent Design" is all about science, why do "Intelligent Design" advocates do much of their speaking at churches?

Q5. If "Intelligent Design" is all about science, why are there 900 articles returned for a search on "cold fusion" from the ISI Web of Knowledge, over 900 articles returned from searching PubMed for "horse feces", and almost none for the sort of thing that "Intelligent Design" advocates mean when they say "intelligent design"?

Q6. If "Intelligent Design" is all about science, why is it that only Christians can be officers of IDEA Clubs?

Q7. If "Intelligent Design" is all about science, why did William Dembski say that it was merely the Logos theology stated in the idiom of information theory?

Q8. If "Intelligent Design" is all about science, why have "Intelligent Design" advocates spent most of their time trying to change K-12 science classes, and hardly any of their time trying to convince the scientific community that they have a good, scientific idea?

Q9. If "Intelligent Design" is all about science, why does the Discovery Institute hire a big public relations firm like "Creative Response Concepts" instead of funding some research studies?

Q10. If "Intelligent Design" is all about paradigm-changing science, why can you find earlier forms of all their arguments in earlier creationist and natural theology literature?