The Watchmaker

Have you ever heard the metaphor of the watchmaker?

When I was in school, I was introduced to the watchmaker metaphor for proof that god exists. It is basically the babelfish argument:

“I refuse to prove that I exist,” says God, “for proof denies faith, and without faith, I am nothing.”

“Oh, says man, but the Babel Fish is a dead give-away, isn’t it? It could not have evolved by chance. It proves you exist, and so therefore, by your own argument, you don’t. Q.E.D.”

“Oh, I hadn’t thought of that,” says God, and promptly vanishes in a puff of logic.

The watchmaker metaphor is less amusing. It states that if you find a watch in the middle of nowhere, you will immediately know it has a creator. Looking at it, examining it, you will find it so intricate and detailed and coincidentally useful that you can only conclude it did not, as Douglas Adams would say, evolve by chance. Similarly, the argument goes on to say, we can look at the world and conclude there must be a god (rather a strange leap in logic, but hey hum).

Interestingly, I was thinking of this when I read about Duhem’s watchmaker metaphor.

It’s not the same thing at all.

Duhem introduces the metaphor to describe the way the scientist examines the problems and searches the field for solutions. The watchmaker, he poses, fixes the broken watch by dissecting it and examining the component parts, yet his other metaphorical scientist, the doctor, cannot dissect his patient, and must analyse the maladies of the whole, using guesswork to discover the symptoms of the true cause. 

The watchmaker often has a more accurate view than the doctor, yet is unable to appreciate the full operational mechanics, because once the lid of the watch is placed back on he can no longer see what is happening inside. He can only imagine it is an associative accumulation of the smaller parts he has studied. The doctor never sees inside the patient clearly and fully, but does see the working model whole.

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About RowenaFW

I am a Fish. But you wouldn't know it just from looking at me.
This entry was posted in A Passing Thought, Back in the Lab and tagged , , , , . Bookmark the permalink.

One Response to The Watchmaker

  1. Hmm… Not sure I agree that it is necessary see inside to appreciate the operational mechanics, simply to know how they work is enough, and here the watchmaker is advantaged by empirical understanding. However, a watch is a relatively simple device, it goes or doesn’t, keeps time or doesn’t. Both of these states are simply resolved, and have few causes. A person is complex, and a lot of information can be revealed by examining the whole (unless the human doesn’t go at all, and does not resond to external stimuli,which case it is generally unfixable). A doctor will often take the patient apart, in the hope that the analysis of the symptoms is correct, and this is indeed informed guesswork, based on their understanding of the relationships between the parts. The watchmaker simply has less to guess at, and less opportunity to observe the internals from the behaviour of the externals, or to kill the watch due to incorrect diagnosis.

    Of course, Duhem was using the metaphor to discuss the impossibility of resolving problems in theory by examining each hypothesis empirically, as the watchmaker does the components of a watch. It is surely because a watch is a small enclosed system that is well understood that this is possible, a physicist has no opportunity to stand outside of the system they examine, and the problem lies in the understanding, not the fixing. For me this is where Duhem’s metaphor falls down. A theory is not a watch (or a person), and a physicist is certainly not a watchmaker, but is attempting a larger task than the doctor, who is still able to stand outside of the problem and observe the symptoms, and able to put the hypothesis arising from the external observation to some empirical examination. The physicist cannot, and no more resembles the doctor than the watchmaker.

    The distinction is important however, and I accept that my criticism may be more due to advances in medical science and surgery since Duhem was writing. Duhem highlights the problems that lie in empiricism when the use of observational tools that are themselves the result of theory develops. If a hypothesis is to be tested, how is it possible to discount the potential failings of the theory used to test it, and discard the hypothesis if it fails the test? One analogy might be that if a doctor theorises that all blood problems manifest in swollen ankles, the absence of swollen ankles will cause the doctor to discount the possibility of a blood disorder, not question the hypothesis underlying the observation methodology. Duhem concludes that all hypotheses within a set are suspect when one is tested and does not come out as predicted, a useful counterpoint to reductionism, but I expect you already knew that 🙂

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