Denyse recently linked to a presentation by Scott Minnich regarding the bacterial flagellum. Minnich is probably among the dozen or so leading experts in the world on the bacterial flagellum. Much of the information in his presentation will be familiar to followers of the issues, but a few points bear further examination.
First a couple of bench-science items that jumped out at me:
Minnich and his team discovered that DNA has a regulatory function in the form of a temperature switch. Let me be clear, it is not that DNA codes for some molecular machine that is a temperature switch. The DNA itself is the switch. In simple terms, the coding portion that codes for a particular protein is bounded by stretches of DNA that are arranged in such a way that they do not permit transcription. However, when the temperature reaches 37 degrees, those DNA stretches change their configuration and permit the coding section to be transcribed and the protein to be produced within the cell.
Despite the empirical evidence Minnich and his team presented for this mechanism, it was initially dismissed by the healthcare community because it didn’t line up with the normal dogma: namely, that DNA just codes for stuff, the old “DNA makes RNA”. The evidence has now accumulated to the point of vindicating Minnich’s early research and a greater understanding of one of the controls for bacterial activity is now more widely accepted, thanks to Minnich’s failure to bow to the traditional evolutionary dogma and thanks to his persistence in the face of institutional and intellectual inertia.
How many times have we seen this before? Science professionals refusing to consider evidence that contradicts their current dogma. In his presentation Minnich also mentioned in passing that evolutionary theory is essentially useless to the work he is doing. “We are doing reverse engineering,” he notes.
Second, Minnich discussed the many proteins involved in constructing and operating the bacterial flagellum and noted that essentially all of the proteins have been discovered through knockout experiments. This, in and of itself, isn’t particularly surprising. But, he pointed out, this is precisely what Mike Behe was referring to in the first place, namely that an irreducibly complex system requires particular parts to operate and that the system breaks down without them.
Without getting into an angels-on-the-head-of-a-pin debate about the definition of “irreducible complexity,” it is valuable to remember this key point: knockout experiments are both based upon, and confirm, the irreducible complexity of biological systems. One can still fantasize about various hypothetical indirect pathways to such a system, but that it has an irreducibly complex core, in the here and now, is an established fact of bench science.
Now, to the main item that really jumped out at me.
Holding Out for a Materialistic Explanation
After discussing the bench science behind the bacterial flagellum and the irreducible complexity of the current system, he argued that the bacterial flagellum was a problem for the Darwinian paradigm and that the Darwinian explanation of mutations and selection was a poor explanation. After the lecture he took questions from the floor. One of the questions asked by a student was essentially as follows:
“Even though Darwinism doesn’t explain something like the bacterial flagellum, shouldn’t we keep looking for a materialistic explanation, rather than jumping to a conclusion of design just because we don’t have a materialistic explanation?”
At this point I actually sat up in my chair and exclaimed out loud to my computer monitor: “C’mon Scott!” This was a great opportunity to hit it out of the park.
Minnich offered a soft answer, acknowledging the student’s right to be conservative and withhold judgment, and then the questions moved on.
What he should have said, is something like what follows.
Now, first let me say that I have taught enough classes, given enough discourses, and presented enough lectures to know that one rarely gives an optimal answer in the heat of the moment. Rarely have I come out of a class or a lecture without wishing I had explained something better, answered a question with more clarity, or had a quicker wit and a more persuasive response to an inquiry. Hindsight is a wonderful thing. So in offering the following, I am in no way impugning Minnich for his presentation, the substance of his lecture, his skill as a presenter or otherwise. He did a wonderful job.
So with the benefit of ample opportunity to think through the issues, enough time to articulate a response, and the exceedingly helpful benefit of hindsight, let me offer the following as a response to the question.
Again, just for convenience, here is the essential substance of the question:
“Even though Darwinism doesn’t explain something like the bacterial flagellum, shouldn’t we keep looking for a materialistic explanation, rather than jumping to a conclusion of design just because we don’t have a materialistic explanation?”
There is a good scientific answer to this question, the one that I thought Minnich might offer. Yet there are also important philosophical issues raised by the question itself, and the question is problematic in a couple of its assumptions. Let’s start with the philosophical issues.
The Philosophical Issues
Problem #1: Materialism is Preferable
The student’s question assumes that a materialistic explanation is preferable, before even looking at the evidence. If we have competing explanations, we should weigh them, see which one explains the evidence better, which one is more consistent with our understanding of how the world works, and then we choose the better explanation. That is how we search for truth. We don’t just assume that a materialist explanation has some inherent value or is inherently preferable over a non-materialistic explanation.
But what about the great success of materialist explanations in accounting for natural phenomena? Sure. But why were those explanations accepted in particular cases? Because they explained the evidence better than other competing explanations and because they were more consistent with our understanding of how the world works. Not because they were materialistic. Furthermore, the “success” of materialist explanations for things in biology like the bacterial flagellum has not been great. It has been terrible. As in non-existent. We don’t need to defer to materialistic explanations in this arena just because they have been good at explaining other natural phenomena. Such an approach commits a category mistake.
So the focus needs to be on weighing and examining the competing explanations, just as Darwin said in The Origin.
Some people, unfortunately, who recognize the lack of a good materialist explanation will say, “Well, we should reserve judgment about inferring which explanation is better, because we might find a materialist explanation.” In other words, they are really saying that even though there is not a good materialist explanation, they are going to withhold judgment about which explanation is preferable. And they are going to withhold judgment until a materialist explanation is found, at which point they will choose the materialistic explanation.
That isn’t science. That isn’t an objective search for truth. That is philosophy. It essentially says, I will only accept a materialistic explanation, even though there isn’t a good materialistic explanation, and even though there is a competing non-materialistic explanation that is preferable to any materialistic explanation we currently have.*
Problem #2: Distinction between function and origin
We are all seeking a natural explanation, in the sense that we expect to find, within the organism, systems and DNA and structures and switches and feedbacks that, within the parameters of physics and chemistry, will explain how the organism functions on an ongoing basis, how the flagellum, for example, operates.
We do not expect that there is no natural explanation — that God or the angels or the demiurge of ancient philosophy are personally intervening to cause the flagellum to spin . . . constant intervention, on trillions of flagella, all around the world. No. We expect to find a way to explain the flagellum, based on what we see in nature and what we find in the organism.**
Let me state this again, because it is important: We expect to find a natural explanation, and to be able to successfully reverse engineer the flagellum, and to understand which molecules are involved and what they do. We hope to be able, eventually, to write a complete engineering-level set of specifications for the bacterial flagellum, specifications that could be used to create our own bacterial flagellum using nanotechnology. All without even mentioning God or deity or anything beyond what is “natural.”
So there is no question that when looking at how the flagellum functions, how it works, how the principles behind it can be utilized for future engineering, there is no question that we are looking for a natural explanation – natural in the sense of something that can be understood, documented, analyzed, and repeated.
However, something functioning within the parameters of natural laws and processes and something being the product of purely natural and material forces are two very different things. In that sense, we have to distinguish between finding a natural explanation for how something currently works and assuming a naturalistic or materialistic explanation for its origin.*** Conflating the two is a serious logical error.
The materialistic claim goes beyond the science. It claims that not only does the flagellum operate in a natural way within the parameters of physics and chemistry, but that the flagellum came about through purely natural and material processes. That is a very different claim. That is a claim that goes beyond the bench science and the reverse engineering. That is a claim that is contrary to the evidence and what we know about how the world works.
The Scientific Explanation
This brings us to the scientific explanation for the design inference, the scientific explanation Minnich could have offered the student if he had had more time.
We aren’t concluding design just because Darwinism doesn’t have a good explanation. Yes, that is part of it. Any time we have competing explanations we need to weigh them. So, yes, we do weigh the Darwinian explanation as part of our analysis and when we find it completely lacking in substance we reject it. But that isn’t why we accept design. Someone could, and many do, reject the Darwinian explanation without inferring design. Indeed, the questioner seemed to do so.
(Let me add in passing that the negative case isn’t a negative case against Darwinism alone. There is a strong negative case against a materialistic explanation generally. Law-like processes are anathema to what we need to produce in biology. And random processes also cut against what we need in biology, in addition to not having the available resources. So we aren’t just rejecting Darwinism as a poor explanation, we have good reason to reject materialism generally, including the various self-organization theories.)
Yet in addition to the negative case against the competing Darwinian and materialist explanations, there is a positive case for intelligent design. When examining a possible explanation we look at the evidence we do have and what we do know about how the world works. What we are dealing with in something like the bacterial flagellum is a highly-complex, functionally-integrated, information-rich system. Based on our uniform and repeated experience, across billions of known examples, every time we see this kind of system it has arisen from an intelligent agent, from a mind.
So, no, dear student. In the case of something like the bacterial flagellum, we aren’t just going to naively hold out for a materialist explanation with the false pretense that we are being “objective”. When the numerous materialist explanations have completely failed and when, based on the best science and evidence we do have, design is the more likely explanation, we are fully justified in drawing a reasonable inference to design. Any demand to hold out for a materialistic explanation in the face of such evidence is really more about a philosophical stance than about an objective search for the truth.
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* We can agree that the non-materialistic explanation is tentative, like all things in science. But, once we examine in detail the evidence in a case like the bacterial flagellum, we need to be clear that it is tentative in the sense that our appreciation of physics is tentative, that our understanding of chemistry is tentative. This isn’t some wild unsupported guess. It is a thoughtful inference based on extensive experience and careful analysis.
** Design theorists absolutely include natural laws and principles in their explanatory toolkit and look to them whenever possible. One of the rhetorical cultural myths regularly put forward by materialists is that people who are open to any kind of non-materialist explanation will “abandon science” and stop looking for natural explanations. That is nonsense, as demonstrated historically and currently. A design theorist certainly isn’t going to invoke design to explain things that can be readily explained by purely natural laws and principles.
Furthermore, beyond the objective scientific approach of design theory, even religious people who believe in miracles expect things to generally operate according to natural laws and would look for that kind of explanation in doing science. Ironically, in contrast to the materialist’s rhetorical talking-point, the very concept of miracles assumes that nearly all the time things do work according to natural laws and principles.
*** For the most part, science can proceed quite nicely without an origins story. Bench science, applied science, and reverse engineering do not depend on origins. They are concerned with what is, with how it works.