Interviewer: Prof. Adnan Aslan (AA), Dean of Academics of Respect Graduate School
Interviewee: Dr. Michael Behe (MB), Professor of Biochemistry at Lehigh University
Keywords
Intelligent design, irreducible complexity, molecular machines, evolution, biochemistry, bacterial flagellum, scientific evidence, design argument, origin of life, science and religion.
Adnan Aslan (AA): Dear Dr. Michael Behe, welcome to Respect Graduate School. Today, if you allow me, I would like to briefly introduce you. You were born in Altona, Pennsylvania, in 1952 and grew up in Harrisburg, Pennsylvania. You graduated from Bishop McDevitt High School, a Catholic school, in 1969. That was a boys’ school, correct? Or were there girls as well?
Michael Behe (MB): Well, no, it was both boys and girls.
AA: You then graduated from Drexel University in Pennsylvania in 1974 with a Bachelor of Science degree in Chemistry. You completed your Ph.D. in biochemistry at the University of Pennsylvania. Currently, you are working at Lehigh University in Bethlehem.
MB: That’s correct.
“When we examine the very foundation of life, we find that it is run by machinery – literally, machines made out of molecules. There are motors, little molecular cars, molecular factories – and many, or even all, of these machines require numerous different parts to function. This arrangement is a hallmark of intelligent design.”
AA: You have published many books, but let me mention three of them, which are particularly important. One is Darwin’s Black Box, published in 1996. In 2007, you published The Edge of Evolution, and in 2019, Darwin Devolves. These are very important works. Could you please briefly explain your version of intelligent design argument?
MB: Certainly. The argument is that when we examine the very foundation of life, we find that it is run by machinery – literally, machines made out of molecules. There are motors, little molecular cars, molecular factories – and many, or even all, of these machines require numerous different parts to function. This arrangement is a hallmark of intelligent design. It is characteristic of minds to organize parts so that they work together to perform specific functions. Since we have discovered such systems at the foundation of life, we should not shy away from concluding that they are, in fact, the result of intelligent design.
AA: So, you see a perfect design at the molecular level.
MB: Yes indeed, these things are very, very strongly designed. They’re much more sophisticated than many of our machines that we know are designed.
AA: So, who is this intelligent designer?
MB: Well, that’s a good question. I’m a Christian. I believe in God. And so it’s natural to think that, since it takes such intelligence to design these systems, God is the likely designer. But in academia – and I’m at a university – you have to make distinctions. You have to make sure you have evidence for your claims. And while the machinery of the cell is clearly designed, it doesn’t have a signature on it. So, if someone else – and I don’t believe this – but if someone says, “Well, maybe it was a space alien who came along and designed it,” then I can’t point to any particular feature and say, “No, this clearly was not a space alien.”
AA: Really? Are those who say that actually serious?
MB: Seriously, they have said so. The universe is designed, and almost everybody comes to the conclusion that, in fact, the designer was God. At the same time, someone might say, “Well, maybe it was an angel or a demon.”
AA: Why are they avoiding saying that the designer is God? Why do they go to aliens, angels, or demons? What’s wrong with them?
MB: Well, the short answer is: I don’t know. There are a lot of people in the world, and they have a lot of crazy ideas. But to argue against that kind of view, you’d have to go beyond science – you’d have to get into philosophy and theology and so on.
AA: OK. My next question is this: “Is the intelligent designer the God of the philosophers or the God of the prophets?”
MB: That’s a good question, too. I think there’s insufficient biochemical evidence to make a firm conclusion. If you mean by the “God of the philosophers” merely a being with the characteristics identified by Aristotle and other noted philosophers – well, as long as that God can act and is infinitely intelligent and powerful, then maybe so. As for the God of revelation, i.e., the “God of the prophets,” clearly He acts in history, too. But since I’m not a philosopher, I wouldn’t be able to distinguish between those two models based on biochemical evidence alone.
AA: Yes, but when you consider the intention, the power, the regulation, and the construction involved – it seems to align more with the revealed God of the prophets.
MB: Well, perhaps so. Again, I’m not a theologian or a philosopher. I try to stick to my discipline of biochemistry. So, when you just look at the structure of these things – the intricate interactions of the parts, how they fit together, how they perform their functions – it becomes a pretty straightforward conclusion to say that they must have been designed by someone who knew what he or she wanted to do. Beyond that, again, we enter into philosophical or theological territory.
AA: Tell me, please, how could you establish the relationship between your argument and Darwin’s evolutionary theory? Are you rejecting evolution, supporting it, or half accepting and half rejecting it?
MB: Okay, that’s a great question. The answer is: no, intelligent design theory does not say that Darwin’s theory cannot account for anything. It says that it cannot account for everything – which is the claim made by many of its proponents. There are, in fact, some things that Darwin’s theory does account for quite well.
AA: What are those?
MB: Well, one example would be sickle cell disease. Many people know that sickle cell disease is caused by a mutation – a change in hemoglobin, which is the blood protein in humans. This mutation can cause the hemoglobin to aggregate, leading to the disease. However, it turns out that people who have one mutant gene, say from one parent, and one normal gene from the other, gain some resistance to malaria. They can survive malaria infections that would otherwise be fatal for people without the mutation. So that’s helpful. But the point is, it’s just one tiny change out of some 500 components of hemoglobin, and it’s not creating anything new. It’s simply a small modification within a pre-existing system. Let me compare this to something more familiar. Suppose you wanted your car to get better gas mileage. Under Darwinian thinking, one change you might make would be to take off the doors and throw them away. That reduces weight, so the car might get better mileage. But now you have no doors, so it’s not ideal. Yet, in a specific situation, the lack of doors could provide an advantage. It’s similar with the sickle cell mutation and other changes that Darwin’s theory can explain: often what happens is a gene is broken or slightly altered, and that may help in the short term. But Darwin’s theory fails when multiple changes are required simultaneously to build a functioning system.
AA: So, if you consider the system as a whole, Darwin’s theory cannot explain the resulting complexity of its design?
MB: That’s right. As I mentioned earlier, science has shown that it’s literally true that machines operate inside our cells. At the foundation of life, we find molecular machines that carry out various functions. And machines, by their nature, are made of multiple parts – and nearly all the parts are needed for the machine to function. You can’t just start with one component; you need the whole set from the beginning. That poses a serious problem for Darwin’s mechanism. I’ve called this property “irreducible complexity.” It means that a system is composed of several interacting parts, all of which must be present for the system to work. If even one part is missing, the entire system fails. In some of my writings, I’ve used a simple mechanical mousetrap to illustrate this point.
“It’s literally true that machines operate inside our cells. At the foundation of life, we find molecular machines that carry out various functions. […] You need all the components in place before there’s anything for natural selection to work on. That’s a major stumbling block for Darwin’s theory. […] This property is called irreducible complexity.”
AA: That is a very simple, but very explanatory analogy. Please explain.
MB: In a mechanical mousetrap, you have a wooden platform, and there is a spring attached to it. The spring holds a hammer, which is pulled back and kept in place until the mouse comes along. There is a trigger, and the trigger releases the hammer. It turns out that if any one of these pieces is missing, the whole thing doesn’t work. So, if you wanted to explain how that was built up through a Darwinian process, where would you start? A wooden platform by itself doesn’t function as a mousetrap, so there would be no reason for natural selection to preserve it. And even a wooden platform with a spring still doesn’t catch mice. You need all the components in place before there’s anything for natural selection to work on. That’s a major stumbling block for Darwin’s theory. Moreover, it turns out that this example isn’t an exception – virtually all systems in the cell are similarly irreducibly complex.AA: Excellent. Your opponents, however, say that the intelligent design argument has no basis in science. How do you answer that?
MB: Yes, a lot of scientists don’t have answers to this issue of intelligent design. But they just want it to go away because, frankly, when you think about it even briefly, it’s clear that the designs we see in life point beyond nature – that something beyond nature is responsible for them. And of course, most people will conclude that the designer is God. Science, however, thought it had gotten rid of God a while back. And many scientists – not all, but many – don’t want to allow any intimations or indications of intelligence or God’s activity back into our understanding of life. I’ve been disappointed because it’s rare for a scientist to actually engage with the argument and try to grapple seriously with the real problem of irreducible complexity. There’s a phrase, “to stonewall the problem.” That means they say things like, “We can answer it! We’re not going to tell you the answer now, but we will in the future!” Or they’ll say, “We already have the answer, but we’re not going to share it with you.” Either way, they avoid the issue.
“It’s based on empirical evidence – or, to put it slightly differently, it’s based on physical evidence. […] When you see a mousetrap, you don’t need prior knowledge to conclude it was designed. […] It’s not a religious conclusion to say a mousetrap is designed. So it shouldn’t be a religious conclusion to say that a molecular machine in a cell is designed, either. We’re using the same logic and the same empirical evidence.”
AA: Yet you still claim that your argument is a scientific one?
MB: Yes, I do. And here’s my definition: it’s based on empirical evidence – or, to put it slightly differently, it’s based on physical evidence. And that evidence is the structure of the machinery we’ve discovered in the cell. The argument is grounded in ordinary reasoning – how we infer design when we observe distinct components arranged in a way that they work together cooperatively to accomplish something none of the parts could do alone. That’s what irreducible complexity is. When you see a mousetrap, you don’t need prior knowledge to conclude it was designed. You can infer that from its parts and how they work together. We see the same thing in the cell all the time. It’s not a religious conclusion to say a mousetrap is designed. So it shouldn’t be a religious conclusion to say that a molecular machine in a cell is designed, either. We’re using the same logic and the same empirical evidence.
AA: And that evidence is what makes it scientific, right?
MB: Yes, that’s what I think.
AA: One more thing – why haven’t you explained irreducibly complex phenomena in terms of natural laws and processes? Why invoke intelligent design and, by extension, a designer?
MB: Well, there are a few ways to answer that. First, we have experience with intelligence. We see intelligence in nature – we are intelligent beings ourselves. We know what intelligence can do. So we explain it based on a power whose effects we can clearly observe. Second, some people say, “We don’t know what intelligence is exactly, or how it arises, or where it comes from.” But throughout the history of science, there have been many times when scientists have explained phenomena using concepts they didn’t fully understand. Take gravity, for example. When Isaac Newton proposed his theory of gravity, no one knew how it worked. It seemed supernatural to suggest that two objects could interact without touching. But Newton proposed it anyway – because that’s what the data suggested. That’s how bodies behaved. In the same way, even if we don’t fully understand where intelligence comes from or how it operates, we can still recognize its effects in the machinery of the cell.
AA: Excellent. Now, your mousetrap example: Kenneth Miller responded to it, saying, “Ironically, Behe’s own example, the mousetrap, shows what’s wrong with the idea. Take away two parts – the catch and the metal bar – and you may not have a mousetrap, but you do have a three-part machine that makes a fully functional tie clip or paper clip. Take away the spring, and you’ve got a keychain. The catch could be used as a fish hook, and the wooden base as a paperweight.” What do you think?
MB: Well, that’s a great example of how people just avoid the question. They don’t want to deal with the argument. What I’ve said about irreducible complexity is that if you take something away, the system no longer functions as it did – it can’t catch mice. Whether or not the remaining parts can be used as a paperweight doesn’t matter – anything can be used as a paperweight! The real question is, “How did the mousetrap come to be? How was it constructed?” If you start with a paperweight, how do you get to a functioning mousetrap? You don’t. So why would you start modifying a paperweight into something else? That line of reasoning avoids the point entirely.
AA: Let us talk about Darwin’s theory of evolution. Is that theory scientifically proven?
MB: No, it is certainly not scientifically proven. It’s interesting to consider that Darwin had no idea what mutations were, even though his theory depended on them. At the time, nobody knew about genetics. Nobody knew about molecules. Nobody even knew that DNA existed. DNA was discovered only about 75 years ago, and only then did scientists realize it could hold the information for life. And it’s only within the last 20 years or so that we’ve been able to see what mutations actually do to genes, thanks to DNA sequencing techniques.
As I explain in my latest book, Darwin Devolves, the mutations that many Darwinists once pointed to as strong examples of Darwinian evolution – now that we can track them – turn out to be mutations that break genes that were already present in the organism. In some cases, that can help. For instance, I begin the book with the example of the polar bear. Polar bears are believed to descend from brown bears, like grizzlies. One of the most helpful mutations in polar bears broke the gene responsible for transporting brown pigment into their fur – making them white instead. That’s useful in the Arctic environment, but it’s still a broken gene. It’s not building anything new. In fact, of the top 15 mutations that most helped the polar bear adapt to its environment, around three-quarters – about 75% – are mutations that broke existing genes. So I argue that Darwin’s mechanism does work, but it works overwhelmingly by discarding or degrading genetic information that was already there, all for short-term benefits. It’s not building anything new.
AA: However, what we actually see is that Darwin’s theory of evolution seems immune to criticism.
MB: Yes. Nowadays, it’s treated more as a postulate than a scientific hypothesis. It’s assumed at the outset, not concluded from evidence. You can do work in evolutionary biology, but you can never disprove Darwin’s theory – because it’s the starting assumption.
AA: But your design argument is a kind of disproof, isn’t it?
MB: It is. But if you talk to a scientist who says, “I will never accept design – I’ll keep looking until I find how Darwin’s theory explains this,” then it doesn’t matter what argument you make. If enough scientists just ignore the argument, it has no effect.
AA: They treat you as a pseudo-scientist, not a scientist. Why?
MB: Calling something “pseudoscience” is a way to dismiss it without addressing the argument. It’s like saying, “You’re bad – go away. We don’t have to deal with this anymore.”
AA: But why is this the case?
MB: Because they don’t have an answer, and they want to preserve Darwinism as a postulate. They don’t have any other explanation for how life could have developed without intelligent input – so they stick to the only narrative they have.
AA: There seems to be a strong force within the scientific community that, to me, appears political in nature.
MB: Yes, you could call that phenomenon political, philosophical, or something else. People certainly use political tools – and whatever else is at their disposal – to suppress any questioning of Darwin’s theory, and certainly any discussion of intelligent design. So, it’s not science at its best.
AA: Then, the truth that must be established by scientific evidence should take precedence over both scientific and religious beliefs. In a sense, what you are doing – as I see it – is establishing a truth grounded in scientific or empirical evidence. Should this evidential basis be considered a form of belief or rather a scientific hypothesis?
“But now, it seems things have gone in the wrong direction – some people simply don’t want to follow the evidence.”
MB: I certainly think it should be considered a scientific hypothesis. When I was being trained as a scientist, we were told to follow the evidence wherever it leads and leave questions of philosophy or theology to others. I always thought that was good advice. But now, it seems things have gone in the wrong direction – some people simply don’t want to follow the evidence. Nevertheless, I still believe that all our scientific hypotheses should be subjected to the best available evidence.
AA: Why is it that some people in the scientific community seem unwilling to explain such phenomena by reference to a deity or something transcendent?
MB: Well, science is, of course, meant to describe nature, and we have other disciplines – philosophy, theology, and so on – that deal more directly with questions about God. It’s true that if you’re dealing with a disease or trying to understand how something functions in nature, there’s usually no need to invoke anything supernatural. However, when you’re addressing fundamental questions like “Where did the universe come from?” “How did life arise?” or “What is a mind?” then you inevitably brush up against philosophical issues. For example, why does our universe have such finely tuned properties that allow life to exist? You can’t just arbitrarily say it must be a natural phenomenon – because at that level, you’re dealing with the origins and fundamental structure of everything. The same applies to life. When we observe such sophisticated, intelligently organized mechanisms in living systems, it’s not enough to say they must have arisen through some mindless process. These questions require deeper investigation.
AA: I will ask the final question. Kenneth Miller challenges your example of the bacterial flagellum. He argues, “No, some part is enough to do the job. We do not need the whole structure [to make the thing work].” How do you respond to that?
MB: Well, that’s essentially the same point we discussed a few minutes ago when we talked about the mousetrap – how, if you remove a piece, you might still use the remainder as a paperweight or a tie clip. That may be true, but you can’t catch mice with it. Now, the machine Miller refers to – the bacterial flagellum – is really an outboard motor that bacteria use to swim. He says that if you take away some of its parts, what remains can still function as a protein pump, expelling materials from the cell. Well, fine – but it no longer functions as a rotary motor. It no longer works as a flagellar motor. So, he’s avoiding my argument. He’s sidestepping the definition of irreducible complexity and substituting his own. That might confuse some people, but it doesn’t actually address the issue.
AA: Okay, thank you very much, Dr. Behe. It was a pleasure speaking with you.
MB: Thank you very much for having me.
