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Why Certainty Doesn’t Always Require Accuracy — A $5 Lesson in Probability

Douglas Axe

This is the tenth part of an ongoing discussion of the central thesis of my book Undeniable: How Biology Confirms Our Intuition That Life Is Designed with my friend Hans Vodder (see here for the whole conversation). The book argues that the intuition we all have from childhood that living things are the work of a God-like designer is correct, and that we can know this without technical training.

Although Hans also attributes life to God, he thinks the evolutionary explanation of life is probably how God got the job done. We disagree on that, but we hope our ability to do so with mutual respect makes the exchange worth sharing.

As I’ve been trying to get to the bottom of our disagreement, Hans has seemed (to me) to be flipping between two inconsistent views — one moment claiming that the argument in Undeniable lacks the precision needed to show that life is designed, and the next offering what appears to be a far less precise argument (based on “counterflow”) that other things are designed.

In the previous post, I pressed Hans to justify this double standard and to explain how he finds counterflow to be a satisfactory concept. Here is his response:

It seems to me we can know some things are designed without having that knowledge verified (that is, we can know without knowing how or that we know, if that makes sense). Verification isn’t required for design knowledge. But that doesn’t mean that our design intuitions are infallible, either. Verification can be important when trying to settle controversial cases.

Biological design is one such controversial case. If one thinks Darwinism and design are mutually exclusive (I don’t, but that’s another matter), appealing to probability calculations might settle the issue. If those calculations are unavailable, then absent some other route, the design question in this case — but not every case! — remains disputed. So, we might need verification in some cases but not others.

As for your concern that “counterflow” is vague and question-begging, the more germane question may be whether the definition is acceptable for the intended use. The counterflow model furnishes a way of analyzing “the conceptual landscape… of broader design debates” but does not attempt to demonstrate design (Ratzsch, Nature, Design, and Science, p. vii). You’re quite right that my use of it falls short of validation. However, that’s only a problem if you think design intuitions need validation in all or most cases, and, as suggested above, I don’t.

Moreover, the conceptual tasks for which counterflow is employed are relatively modest compared to the bold proposals of Undeniable. The argument from functional coherence attempts to demonstrate the designedness of biological organisms and thereby to repudiate the whole of evolutionary biology. Whether the argument can succeed without more explicit definitions remains an open question, but given the book’s decidedly ambitious goals, it only seems fair that it should face stricter scrutiny.

It goes without saying that we humans don’t need to justify everything we believe to be obviously true as we go about our lives. But you and I aren’t merely going about our lives here, Hans. We’re trying to discern which of our views is correct, which will require us to justify beliefs that might not ordinarily need to be justified.

As our dialogue continues, I think I’m starting to understand your position more clearly. You agree (I think) not only that we all believe natural processes occurring on a lifeless planet can’t produce things like adjustable wrenches and communications devices but also that this belief is correct. In Undeniable I offer an explanation for why this belief is correct for a whole class of things. Although you and I disagree on what belongs in this class, I think you accept that there is a large class of objects that not only does trigger our design intuition but also should trigger it, in that the whole class really is beyond the reach of natural processes. Yes?

My explanation for this centers on what I have called functional coherence: the hierarchical arrangement of parts needed for anything to produce a high-level function — each part contributing in a coordinated way to the whole (p. 144). In short, I argue that functional coherence explains both our perception that certain things are beyond the reach of nature and the fact that these things really are beyond the reach of nature. Specifically, for accidental causes to create something with high-level functional coherence would be both an unbelievable coincidence (according to intuition) and a fantastically improbable event (according to math).

I know you doubt this, Hans. I’m just trying to pinpoint the root of our disagreement. To that end, I’m now seeing two key points on which I think we ought to agree.

First, as I’ve said previously, to show conclusively that something is effectively impossible doesn’t require an accurate probability calculation. Picture, for example, climbing a 12-foot step ladder with a jar of 500 pennies, and then pouring the pennies out to fall to the floor. Our intuition assures us that for them to just happen to land all heads up in neat stacks of fifty coins is impossible, practically speaking. While there’s no way to put an accurate number on the probability of this, there is a way to show that this number is so small that our intuition is justified. To do this, we notice that all the pennies would, in the first place, have to land heads up. They would have to do much more than this (not only heads up but, more remarkably, in neat stacks of fifty), but the mere requirement that they all land heads up itself provides a simple calculation that fully justifies our sense of this being an impossible outcome.

By straightforward math, our penny-dropping experiment would have to be performed about 2500 times for it to become probable that all 500 pennies “merely” land heads up (without having to be stacked). To be precise, if the experiment could be repeated

times, then the odds of all heads occurring would be dead even. But even taking the capacity of our entire universe into account, this is so far beyond the realm of physical possibility as to rule this coincidence out decisively. And since all heads and stacked is even less probable, it too is completely out of the question.

So, to the interesting fact that we all immediately perceived this outcome to be impossible we can now add the scientific fact that calculation handily confirms our perception. We can talk about life next, Hans, but first I want to make sure you’re happy with the fact that we can indeed show certain outcomes to be effectively impossible without knowing their probability.

The second point we ought to agree on has to do with burden of proof. You say that because I’m arguing that a whole field has got it wrong, my argument should face stricter scrutiny. But that isn’t actually how science is meant to work. All ideas are meant to be carefully scrutinized, irrespective of their popularity. Undeniable quotes Neil deGrasse Tyson’s “simple set of rules” for doing science (p. 37): “test ideas by experiment and observation; build on those ideas that pass the test; reject the ones that fail; follow the evidence wherever it leads; and question everything.” This is spot on as an ideal, though Tyson is naïve to suggest it’s how science actually works in the real world (I don’t think we’d still be dealing with Darwinism if this were how science really worked).

On the central question of whether natural causes can invent the things of life, I’m not nearly as impressed with “the whole of evolutionary biology” as you are. But instead of arguing about that, we should agree to let the evidence decide the matter. If all this Darwinian science really amounts to something, then you have the advantage of being able to draw from it. On the other hand, if this massive body of work doesn’t enable your position to stand up to strict scrutiny, Hans, then maybe you should downgrade your opinion of it.

Photo credit: Olichel, via Pixabay.