"What embitters the world is not excess of criticism, but an absence of self-criticism." - G.K. Chesterton

Friday, February 22, 2008

Argument from (evolved) design

In crossing a heath, suppose I pitched my foot against a stone, and were asked how the stone came to be there; I might possibly answer, that, for anything I knew to the contrary, it had lain there forever: nor would it perhaps be very easy to show the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place; I should hardly think of the answer I had before given, that for anything I knew, the watch might have always been there. (...) There must have existed, at some time, and at some place or other, an artificer or artificers, who formed [the watch] for the purpose which we find it actually to answer; who comprehended its construction, and designed its use. (...) Every indication of contrivance, every manifestation of design, which existed in the watch, exists in the works of nature; with the difference, on the side of nature, of being greater or more, and that in a degree which exceeds all computation.

– William Paley, Natural Theology (1802)

This is the most famous expression of the “watchmaker analogy”, often used in support of the 'Intelligent Design' “theory” of evolution.

The basic idea is that as we know that certain examples of complexity around us (watches, computers, the faces on Mt. Rushmore) have been designed by intelligent minds we are justified in assuming that examples of complexity in the natural world (the eye, echolocation) were similarly designed.

However, I think that this idea is seriously flawed in its understanding of designed complexity. Concepts such as the watch or computer did not suddenly spring, fully-formed, into the mind of their designer – but are actually as much the result of mutation and natural selection as any biological system. In order to make clear what I mean, I'll provide a rough outline of how I think the modern concept of the watch evolved:

The ancestor of the modern watch was a simple Concept allowing prehistoric man to structure his day more efficiently – probably no more complex than a distinction between earlier, now and later.

The means of replication was language – Man A would express the concept, spreading it to the mind of Man B. During replication, mutations would creep in, partly through errors in communication and partly through the interaction of the Concept with the other concepts found in the mind of Man B.

Some of these mutations would make the Concept less effective, thus making them less useful and (therefore) less memorable and impeding the spread of that variant. Others would make it more effective, thus making it more memorable and useful and increasing the spread of that variant.

Thus, natural selection comes into play – with increasingly complex variants of the Concept vying for a place in the human mind.

Over time, variants of the Concept become increasingly complex and some evolved to take advantage of man's ability to manipulate his environment – leading to the development of increasingly complex timepieces, which, by increasing the exposure to that design, increase the chance of that particular variant spreading into other minds.

Thus, the watch that Paley stumbles across can be seen as a sort of extended phenotype, “designed” to promote the spread of the Concept in the minds of man, and as such would seem to support rather than challenge the concept of evolved complexity.

What do people think?

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Blogger Incitatus4Congress said...

Check this out.

It has its limitations, but it is nevertheless a rather good rebuttal of the blind watchmaker analogy.

1:07 PM

Blogger Incitatus4Congress said...

Oh, and as PZ Myers points out, biological clocks equal to anything the Swiss can come up with are ten-a-penny in nature.

1:10 PM

Blogger Timmo said...


I suspect Paley would not be impressed by the line of argument: the watch is a product of human beings, and, since human beings are the product of a random process, so is the watch. While this is correct so far as it goes, Paley might argue that you are begging the question.

I prefer to meet this argument head on and challenge the intuition behind irreducible complexity. That is, I challenge the idea that certain orderly structures can only be the result of conscious design by introducing what Robert Nozick called invisible-hand explanations. Nozick explains these explanations, "A pattern or institutional structure that apparently only could arise by conscious design instead can originate or be maintained through the interactions of agents having no such overall pattern in mind. Following Adam Smith, I termed such a process or explanation an invisible-hand process or explanation..."

As it happens, some structures that we would intuitively identify as orderly are entropically or thermodynamically favorable. This results in the phenomenon of spontaneous, unsupervised organization, or self-assembly. I talk a bit about this in my post Irreducible Complexity or Self-Assembly?.

2:05 PM

Blogger Matt M said...

Hey Timmo,

I wasn't really intending this as a knock-down argument against irreducible complexity - largely because I don't think it really offers anything to knock down.

In order to say that something is too complex to have been created through natural forces surely we have to firmly established what the exact limit of those forces is and, hopefully someone will correct me if I'm wrong here, we don't seem to be anywhere near such an understanding of the universe. I could understand someone arguing that an object was too complex to be explained by current theories, but isn't the idea that it could only possibly be explained by one theory (in this case an intelligent designer) stepping beyond the bounds of science?

What I intended (hoped for) this post to illustrate is that the line between designed and evolved is quite blurry. So that we're just as justified in describing a computer, for example, as something which evolved, as well as being designed. (Maybe it's best put like this: Specific instances are designed, but the concept from which the design is drawn can about through evolution - simple ideas mutating into more complex ones - rather than design). I think the charge of question begging can be avoided - after all, we know for a fact that the concept of computers has evolved over the last couple of millennia. Unless the Greeks had the equivalent of the Mac Airbook. :-)

2:52 PM

Blogger Crushed said...

I don't if you are familar with the Red Queen hypothesis, but it basically answers those points.

Better geological and genetic knowledge over the last ten years has enabled us to understand better how complexity breeds complxity as evolution keeps moving faster to stand still.

There is only statistically unusual event in the evolution of life, the emergence of Eukaryote life.

11:42 AM

Blogger Alex said...

Hey Matt,
I agree with you that man has a habit of evolving his tools over time. It's also rather creepy to consider the rate at which we are moving these last 2000 years. Our inventions are evolving at speeds that leave whatever biological evolution that may have occurred coughing in the dust. I wonder if this "cambrian explosion" of man's creative ability might stalemate for a few million years like biological evolution seems to have a habit of doing. If not, I wonder what will be come of us before the end.

2:32 PM


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