Thinking Christian

This is the second stage of an argument responding to what I have called The Complaint: that Intelligent Design’s (ID’s) negative argumentation against naturalistic evolution (NE; defined here as the development of life and its complexity through undirected random variation coupled with natural selection) is somehow illegitimate, unscientific, or otherwise weak or wrong. If you have not read the first stage, that would be the place to begin.In it I showed that in the simple case where we assume there are only two options on the table, negative evidence against NE is quite clearly positive evidence for ID. I expressed this in the probability equation 1 – p(NE) = p(ID), where p(NE) is the probability that NE is the true explanation of origins, and p(ID) is the probability that ID is the true explanation.

Now we must examine the possibility of more than two options. As I said last time, this argument becomes complex. I have placed a tree-diagram representing the whole of it at the end of the third post in this series. You may skip ahead and use it to guide you through if you like.

Recall that ID stands for origins being brought about by a designer. If there is a third option it cannot involve a designer, for that frame is already filled by ID; it must be another naturalistic explanation. At this point there is no naturalistic explanation on offer besides NE, so it must be an unknown naturalistic explanation. I will refer to it as the Unknown Naturalistic Theory, or UNT.

If we are to grant the entirely reasonable assumption that science could develop some other, new naturalistic explanation for the development of life and its complexity, then the probability equation we started with must be expanded:

p(NE) + p(ID) + p(UNT) = 1

We have no way of assessing UNT’s probability, but we can deal with that by considering two possibilities.

A.
p(NE) + p(UNT) = 1;
  p(ID) = 0

B.
p(NE) + p(ID) + p(UNT) = 1;  
0 < p(ID) < 1;
0 < p(UNT) < 1

I will deal with A in this post and save B for the next in this series.

A is a mathematical restatement of, “We won’t claim we’re absolutely certain that NE explains life’s origins; but we’re certain that whatever the explanation is, Design had nothing to do with it.” Often coupled with this statement is something to this effect: Science has made continuous progress in finding naturalistic explanations for natural phenomena. Attempts to use God (or some other Design process) to explain natural phenomena have consistently had to give way to naturalistic explanations. Therefore we think it’s reasonable to conclude that science will eventually demonstrate that the origin and complexity of life have fully natural explanations, whether NE or some other theory not yet conceived of.

The question there is, what evidence is adduced for this opinion? There is one kind of evidence that is offered, and another kind that is not even in the picture. What is offered is the history of science, and what is inferred from that is an extrapolation to the future of science. What is not even in the picture is evidence from nature. No matter what evidence E might surface in nature at any time in the future, E can only count as evidence for naturalism (NE or UNT), for p(ID) = 0, world without end, Amen. The probability of naturalism today, T1, is 1; the probability of naturalism tomorrow T2 will be 1, and the probability of naturalism at T3, T4, T5 … to infinity is 1. And this we are assured of, regardless of what evidence E might be introduced at some time Tn in the future.

That is either begging the question, simply stating ID is wrong and that’s that, regardless of what evidence should ever appear! or else, if it is not begging the question, it is placing enormous load on the evidence that has been offered on its behalf: the history of science. We must recall that science has not had uniformly increasing success in explaining what we observe in the world. It has gotten nowhere with explaining realities like consciousness, reasoning, purpose, meaning, free will, moral responsibility and even the origin of the first life. (Claims to the contrary abound, but as I — and many others — have argued elsewhere, they are philosophically uninformed.)

But even if that were not the case, extrapolation in a matter like this is hardly more than an expression of faith. To extrapolate without a supporting theory is bad statistics and bad science, and the only theory that could support this particular extrapolation is one that begs the question: the theory that all of life’s features will someday be explainable naturalistically.

So version A above is unsuccessful. To introduce p(UNT) into our probability equation that way is logically fallacious. We’ll have to pUNT (I’ve been saving up for that pUN) to version B and see whether it works. That will be the topic of the next post.

Series Navigation

«The Evolutionists’ Complaint: It’s Wrong to Argue For ID By Arguing Against Evolution (Part 1 of 3)The Evolutionists’ Complaint: It’s Wrong to Argue For ID By Arguing Against Evolution (Part 3 of 3)»

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3 Comments

1. Jennifer (Conversion Diary) says:

   January 30, 2010 at 12:38 am

   Wow, great post. I just now discovered your blog, and as a former atheist, I find the topics you cover to be fascinating. I look forward to reading more. You’re doing great work here; keep up the good work!
2. Tom Gilson says:

   January 30, 2010 at 5:58 am

   Thank you, Jennifer. I’ve had your blog in my RSS reader for a few months now, and your words here are a real encouragement to me.
3. William Bradford says:

   February 6, 2010 at 1:30 am

   Not only is it wrong to argue against evolution- it’s just plain blasphemous.

   http://telicthoughts.com/channeling-religious-impulses/