Field of Science

Intelligent Design is a failed scientific theory

Update February 6, 2009:
Make that "failed scientific hypothesis."

A Kalamazoo (MI) resident defends evolutionary theory and makes the point that has been made many times before, that intelligent design is not a scientific theory.

Disclaimer: I do not think there is any merit to intelligent design. I believe that there is no system/structure/pathway/organ/organ that's irreducibly complex, and I believe that life originated and evolved by natural processes without the aid of any designer of any kind, whether scientists will be able to verify how all such systems, etc., originated or not.

From Kalamazoo the word is this.
Intelligent design is a philosophy. There is no test we can run to check intelligent [design], so it can never be considered a scientific theory. Therefore Intelligent Design should never be taught in a science classroom. It should be taught in philosophy class instead. That's still true.
Why is it that intelligent design is not a scientific theory? Is it really not?

The problem is that to verify (i.e. prove beyond any doubt) that a system is not designed by an intelligence, we have to show that there is no way it could have evolved (here meaning appeared by natural processes only). If one scientists have given up finding an explanation for, say, the origin of life (abiogenesis), he may conclude that there is just no way it could have happened by natural means, and that it must have come about by design. However, another scientist might have a go at an explanation, and when she gives up, a third may come along keeping up our hopes (if, like me, that's what we hope for). There is no way to completely dismiss the idea that a system has evolved by natural means, and many people, like our hero from Kalamazoo, thus concludes that the theory of intelligent design is thus not a scientific theory (since to qualify as 'scientific', a theory must be falsifiable).

While I, and I repeat, do not think that there is any need to invoke a designer to explain anything observed in nature, I also do not think that there is a strong enough reason that intelligent design should not have status as a scientific theory. Please let me explain before you run away and accuse me of heresy...

The notion of falsifiability comes from Karl Popper, and is largely agreed upon by anyone who knows the first thing about science. It means that to be scientific, a theory must be falsifiable.

However, nothing in science can be verified with complete certainty. There are no P-values that equal zero. That then means that we can never be sure that we have the right explanation for anything. Ever. We can be pretty god damn sure, if we keep testing our hypothesis and the evidence always confirms it. But that's how things are, and we are content enough that that's all we can do. People who believe science works another way are mistaken. Grrr!

Let's return now to intelligent design, and the specific hypothesis that the origin of life is irreducibly complex. Can I falsify this? Why, yes I can. If I find a way that it could work by natural means, then that would do the job. That hypothesis in turn would then have to survive all attacks of falsification, but if it does, then it's one up for nature, and zero for the intelligent designer. The problem with intelligent design is then that it can just move on to another system, and say "well, okay, origin of life could have happened by natural processes, but how about the flagellum, eh?" And then real scientists would go to work on that system, and when they, after years and years of toiling, have satisfied most everyone in the scientific community who cares enough to comment, then we can also rules out flagellum as having been under the knife of our hypothesized designer. Two-nil for nature. But... then a third structure is posited as irreducibly complex, and the scientific process starts all over again (hopefully funding doesn't run out in the meantime).

Repeat this ad infinitum, and someone might still suppose that some other system is irreducibly complex, right? Well, no. For two reasons. First, at least in principle, there is actually a finite number of systems (or of anything, for that matter, in a finite Universe - or at least on our very finite Earth). So, at least in principle, it is actually possible to falsify the claim that there is at least one such intelligently designed system among organismal life forms on Earth. If you object that that will never happen, you'd be quite right. In that case, recall that in science we don't actually need to be so certain to accept a claim as scientific fact. We just have to falsify a thing a good and solid number of times, and I don't see any reason why this should not apply to the hypotheses of intelligent design theory. On second thought, let me rephrase that. There is no good reason why it would not be enough to falsify specific claims of irreducibly complexity a finite (and manageable) number of times in order to falsify the larger claim that there are any such irreducibly complex systems at all.

The state of things is that many of the systems that Michael J. Behe in Darwins Black Box claimed were irreducibly complex have been shown beyond scientific doubt to not be irreducibly complex. That includes the blood clotting cascade, the flagellum, eyes, and most recently there is now a lot of buzz about a soon-to-be famous experiment by Lincoln and Joyce, who in an experiment with RNA have shown one possible way that non-living enzymes could use monomers to make copies of themselves for as long as they shall live. That's admittedly only a few out of the many systems that could be posited to be designed. But it's a very good start. We are on our way to falsify the claim that there are any systems that are irreducibly complex, and thus we tentatively conclude that there is no system that is designed.

Thus (and thank you for reading this far) I don't see any problem calling intelligent design a scientific theory. It's a failed scientific theory, though. None of it's claim have so far held up. I predict that some years hence it will have no serious adherents anymore, by which I mean scientists who are not hellbent on a God Proof. There are those around, I am aware. Those who will not face the facts, and who dismiss evidence when it flies in their faces. Science - this wonderful endeavor for knowledge - has no need for people like that.

Lastly, I would like to caution those who too readily dismiss scientific claims because those who claim them are religious people out to prove their foregone conclusions. While such a predisposition toward a religious agenda certainly does not shine a fair light in search for knowledge, it also does not devastate it. In fact, recall that many famous and revered scientists were not just religious, but also out to prove the existence of God through examining his wonderful creation. In other words, the origin of intelligent design may be one of creationism (okay, it is), but Tycho Brahe did not observe the heavens, laying the foundation of Kepler's laws, leading to Newton's laws, et cetera, et cetera, because he was interested in nature. He did it because the Danish King at the time commissioned him to make precise observations of the planets so accurate horoscopes could be constructed. No one in their right mind would dismiss that famous Dane's contribution to science because his motives were astrological.

Update 6/15/2009: I realize now hat I have been conflating Intelligent Design and irredicible complexity. Apologies. I no longer stand by the previous statements that ID is scientific, but only that IC is a scientific hypothesis.

Related posts:
Taking Intelligent Design seriously
10 minutes on Intelligent Design
Why teach Intelligent Design?
The red swan hypothesis
The big Judge John E. Jones III interview
Khmer Rouge chemistry


  1. I think you're being too narrow in your definition of science - it doesn't reflect what happens in practice. Although Popperian falsifiability is an important concept, there more to it than that - a negative experimental result rarely causes the rejection of a theory. Hence Kuhn and his concept of paradigms.

    Also, there are many concepts that are not disprovable, and yet are widely regarded as scientific, at least in some sense. Cosmology provides lots of examples. What tends to happen in the selection of optimal scientific theories is a kind of Bayesian inference, rather than simple falsifying.

    However, the reason ID is not scientific is that the bedrock of science is methodological naturalism. In other words, magical explanations are excluded by definition.

    It's clear why this is. For every question with no natural explanation, there are two possible responses: 1) I don't know, or 2) it's done by a magical intentional being (gods or fairies or something).

    Response 2 is always viable, in some sense. But science cannot accept it as an answer to the question (because otherwise science would never progress).

    When you have a scientific explanation, then further scientific investigation is unnecessary. But a magical explanation does not exclude further scientific investigation. And just because you don't have a scientific explanation can't be regarded as evidence that the magical one is true.

    In other words, magical explanations cannot substitute for scientific ones - they are from fundamentally different philosophical well springs.

    This doesn't mean to say that there are no magical explanations that are true. For all I know there may be. But they are not scientific. And ID is one of them.

  2. Hi Tom.

    I agree with your point about the Bayesian inference. But that is what I am trying to say, that the probability that something (anything) is intelligently designed is updated every time we learn how something has (could have) evolved. At every update that probability is lowered.

    You say that ID is not scientific because magical explanations are excluded. I only half agree. Magical explanations are excluded, but design is not magic. In other areas of science, design is regularly inferred. In anthropology, for example. The big difference is that once design has been inferred, ID just has no valid scientific explanation of who that designer is, while in anthropology we surmise that it is a human (or a relative).

    The fact that many adherents of ID actually do believe in magic is besides the point, as I tried to explain above.

    When you have a scientific explanation, then further scientific investigation is unnecessary.

    Here I must disagree. I think there are many good examples that this is not true. Gravity. There was an explanation, and no one had reason to doubt it. Then Einstein came along (and reasons to doubt classical mechanics subsequently appeared). Additionally, oftentimes an explanation cannot readily be rejected, but that doesn't mean that others aren't evaluated in parallel. Further investigation is not unnecessary.

    Lastly, I also don't have a problem teaching ID in science class. In it's entirety, it could go something like this:

    "Intelligent Design is a theory that some things could not have evolved by natural processes, but must have been designed purposefully. So far this claim has not held up to scrutiny, and most scientists give no credence to it, and it has thus gone the way of phrenology, pangenesis, Lamarckism, and the Dodo."

  3. Creationism as a scientific theory is unacceptable since it either includes a supernatural creator (God) or it relays the problem to: who created the creator? In case we were created by say: Aliens - who created the aliens?

    Why is God not a scientific explantion? If one does not know the answer to this, I feel deeply sorry for him/her ... or in other words: for every question, there must be a scientifc answer, or the question wasn't about the thing we call reality.

    In this sense I totally agree to Bjorn and think that we should undertake science in the most narrow and strict way possible


  4. Two comments, really. There actually are "things" out there in Scienceland that masquerade as Science in a manner somewhat reminiscent of ID. I'm thinking of so-called "Fifth-Force" experiments. There are physicists out there who look for a force beyond the "Great Four". There is no evidence that there should be one, nor do we have any theoretical construct that tells us that there should be one, yet, there they are, doing experiments, many of them federally funded. According to me (and some scientists do disagree with me here) this is just like ID, but with the supernatural belief in a creator replaced with a variation of crackpottism. Or they may be the same, what do I know?

    Second comment: If you take the definition of "irreducibly complex" literal (and that is difficult to do because the adherents like to change definitions at the drop of a hat when it is convenient) there actually are irreducibly complex things in Nature. The trouble with the so-called theory is not that there aren't any such things, the trouble is that we have shown that they evolve quite readily, thank you. Our 2003 Nature paper, even though it wasn't designed to address this point, showed just that. According to the ID definition, the "EQU" task is irreducibly complex. Yet, we evolved it over and over and over again.

  5. I think I actually agree with the resident from Kalamazoo to an extent.

    It seems, from this post and the comments and things I've read elsewhere, that proponents of intelligent design want to point to specific things in nature as evidence of a designer. By so doing they are making a scientific theory out of a philosophical viewpoint. This leads, as you correctly point out, to a failed scientific theory. And a lot of angry religionists who think that science hates them and wants to force them to deconvert and stop worshipping as they choose!

    As a philosophical position, however, there's nothing especially wrong with asserting a designer. But you can't say "my flying spaghetti monster designed RNA in his magical laboratory and released it on an unsuspecting universe." Instead you have to say, "my flying spaghetti monster designed a universe in which the laws of physics and the properties of matter and energy made it possible for RNA to develop." Or maybe even, "the flying spaghetti monster exerts its will by influencing the outcomes of apparently random events, biasing cause-and-effect processes in nature towards the outcomes it prefers."

    These things can be pleasant to think or conducive to mental health for those who believe them. They may even have some veracity, who knows? But they are philosophical assertions! And people who try to pass them off as anything else, I think, are trying to steal the credibility of science to convince others of their own favorite ideas.

  6. Bjorn: You say that ID is not scientific because magical explanations are excluded. I only half agree. Magical explanations are excluded, but design is not magic.

    Think of it this way: The theory of 'Irreducible complexity' is a scientific theory, of sorts. But inferring an intelligent designer is not. The problem with these magical, intentional beings is that they have no fixed properties. Suppose there was no irreducible complexity. Would that be evidence that an intelligent designer does not exist? No. It would simply mean that the intelligent designer chose to design things that were not irreducibly complex!

    In other words, you can't disprove a magical intelligent designer. But you can infer its non-existence by Bayesian means.

    And that's where the similarity is with anthropology. Ancient egyptians have known properties. If you could prove that ancient egyptians could not have built the pyramids, then you would have evidence that there is something missing from your knowledge. But that would not in itself be evidence for aliens. It would be evidence of your ignorance.

    Regarding the scientific explanation and further investigation. What I mean is that if you have a scientific theory that has been tested, fits the facts, and is the most parsimonius, then you have a scientific solution. Of course if the facts change, then you need a new theory - that's what happened with Einstein (that and new mathematical techniques). But you're right that all scientific explanations are provisional, never final.


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