The most recent episode of Unbelievable? features a debate between philosopher Peter S. Williams and biochemist Keith Fox. The focal question was, “Is Intelligent Design Science?” Keith Fox, whom I have debated myself, is one of the more friendly critics of intelligent design. However, disappointingly, Fox’s critiques of ID have not progressed at all since my own debate with him in 2018. Indeed, Fox has also been corrected on these same arguments in previous debates with scientists including Michael Behe, Douglas Axe, and Stephen Meyer. His interlocutor on this occasion, Peter S. Williams, did a fine job pushing back on Fox’s objections, giving responses that are essentially what I would have likely said in reply to these critiques.
God of the Gaps?
For example, Keith Fox alleges that intelligent design is a “God of the gaps” argument — that is, an argument based upon ignorance rather than being a positive inference. But Fox has been corrected on this multiple times before. The case for intelligent design is certainly a positive inferential argument. Now, perhaps there is something erroneous about the inference we make to design. But to assert that there is no positive inferential argument being made at all is factually incorrect. If there is something wrong with the case, it is not that it is a “God of the gaps” argument. For example, see this discussion I had with my colleague Dr. Tim McGrew for the ID the Future podcast in which we hash out the argument for design in Bayesian terms.
Indeed, the claim that ID constitutes a “God of the gaps” fallacy also fails for the reason that there are phenomena in nature that we do not understand, and yet for which we do not infer that they are best explained by design. For example, we do not at present fully understand the precise mechanisms that trigger glacial-interglacial cycles. Nor do we understand the neural pathways involved in the placebo effect, and why belief apparently can trigger measurable physiological changes. However, we do not infer that these phenomena are better explained by design. If we do not invoke design in these case, then, Fox (and other critics who use this objection) must show why we infer design in one case and not the other.
Williams explained to Fox the concept of specified complexity and how it provides positive evidence for design. He asked Fox how he would justify the fine-tuning argument, since presumably the “God of the gaps” charge could be leveled against this argument just as readily. Fox replied that he has no problem with the fine-tuning argument, since this is based on things we know about the constants and parameters of our universe. By the same token, though, I would say that we know that the preponderance of significantly sized proteins that form stable structures is astronomically small. Likewise, we know that certain biological systems are irreducibly complex. Though Fox asserted that he does not believe that irreducible complexity has been demonstrated for any system, it seems to me that it is not only true but obviously so that some systems are irreducibly complex. For example, see this article or this podcast interview on the irreducible complexity of the DNA replication machinery. This is a particularly convincing example of irreducible complexity. It is far more difficult to envision any kind of co-optation scenario than it would be for a system that arose much later, such as bacterial flagella. With the flagellum, one can at least point to alternative functions that might be performed by a number of the flagellar components (such as the Type III Secretion System). However, with DNA replication, it is unclear what other systems any of the components might be co-opted from — since any other system would need to have arisen after the origins of DNA replication.
Testable Predictions
Fox also contended that ID is not science because it does not make testable predictions, nor is it falsifiable. However, ID does makes predictions. When one hypothesizes that a particular feature of the world is the product of design, a testable prediction that falls naturally out of this hypothesis is that said feature will exhibit specified complexity, the hallmark of conscious design. For example, the work of Douglas Axe and others on protein folds, confirming that stable and functional sequences are astronomically rare (relative to the much larger number of sequences that do not form stable folds), confirms a prediction of the hypothesis that proteins are the product of design rather than unguided processes.
Falsifiability
As for falsifiability, this demarcation criterion is now generally disregarded among philosophers of science. Most complex systems or theories are not overturned by a single anomalous piece of data. Instead, the relative probability of a hypothesis may increase or decrease as new data comes in, and ID is no different. The same thing is true of evolution — it would be imprudent to throw out the theory on the basis of one or a few anomalous pieces of evidence that do not comport with the standard paradigm. However, new pieces of data can render the theory more or less probable. If disconfirming data accumulates, a theory can break under the strain. The degree to which a theory can tolerate anomalous data correlates with the strength of the case supporting it.
Moving the Goalposts?
Fox asserts that ID proponents are always moving the goalposts:
It started with the bacterial flagellum. Well, we have evolutionary mechanisms… And then we move on to the blood clotting cascade, and the human immune system. And each time I’m really pleased that the intelligent design people raise these issues because actually it causes serious scientists to sit down and think, “I wonder how this could have been.” We do some experiments. We’ll look at the bioinformatics and all the rest of that lot and we work it out and the goalposts keep moving.
I would reject that any of the systems Fox lists have been satisfactorily accounted for by evolutionary processes. Does he really think we are limited to asserting only a single example? No, we think that all of these systems (and many more) are demonstrably irreducibly complex. To talk about multiple or new examples is not to concede that previous examples have been refuted.
Fox also incorrectly asserts that “most of the ID literature now is not focused on evolution — how life has changed over time — but actually on abiogenesis, which is ‘how did life arise?’ And that is a totally different question… So I see the goalpost is moving rather than sitting with a fixed target.” I don’t know what ID literature Keith Fox has been reading but this is simply not true. For sure, there is a definite interest in the origins of life, which is a strong case for design in its own right. But we have not at all given up on making the case that there is evidence of design downstream of the origins of life as well.
Stuck on Talking Points from the Early 2000s
Fox’s objections to ID bear a strong resemblance to critiques from the early 2000s. It does not appear that he has kept up with developments in ID over the last couple of decades. Moreover, Fox makes basic errors about what ID is that have been corrected and pointed out to him on multiple occasions before, including by myself. On the other hand, I cannot fault anything that Peter S. Williams said in the debate. His rebuttals were exactly on-point throughout. It was refreshing, though, to see this debate conducted with professionalism and amicability from both sides — something that cannot always be taken for granted.