Explanation or Description?

2004 Most Civil Debater · Post 1: Fri Feb 24, 2006 3:23 pm Post subject: Explanation or Description?

There is a curious phenomenon in the Evolution controversy. We've seen it many times in these threads, but I'll illustrate it with some quotes from other sites:

Post 2: Sat Feb 25, 2006 1:30 pm Post subject: Re: Explanation or Description?

Jose,

That must be a record for the longest first post on a thread! But you raise some good questions. Explanation -- what is it? Consider Thales:

2006 Most Civil Debater · Post 3: Sat Feb 25, 2006 3:10 pm Post subject:

A couple of good posts.

My initial thoughts are as follows:

Should scientific description precede scientific explanation? I would say this does not seem unreasonable. HOwever, one must go back to Jose's point and ask 'what level of detail of description is necessary?'

For example, with respect to evolution, we could describe all the evidence we have. We could describe the fossils we have, where we found them both geographically and strata-wise, what other fossils were found in the same layers and locations, etc. etc. We could describe the genetic diversity we find, both in the present and to the extent we have evidence for it, in the past. We could describe the geological layers themselves.

Will we ever have a complete description of all the possible data relevant to explaining the history and diversity of life? I don't see how. But as Jose notes, I don't think this means we ignore the evidence we do have.

Now, how much evidence do you need before you try to find an explanation for the evidence? I don't see how you can draw a hard and fast line on this. The general rule is, the more evidence we have, the more restrictions there will be on possible explanations, and the more likely we are to be able to provide more reliable and more detailed explanations. If we have a paucity of evidence, our explanation is more likely to be speculative. But, we can still provide the best explanation for the evidence we have.

Detectives and prosecutors trying to obtain a conviction will obviously try to obtain as much evidence as they can relative to the crime. However, they will try to provide the best explanation they can even in the face of scarce evidence. The question is, when do they have enough evidence to make a good case against a specific defendant?

So, yes, I would agree there needs to be some amount of description of phenomenon (e.g. data) prior to developing an explanation, but it seems to me the point at which you go to the 'explanation' stage is somewhat of a judgment call.

2004 Most Civil Debater · Post 4: Sat Feb 25, 2006 4:15 pm Post subject:

You both raise interesting points. I'm particularly intrigued by yours, rigadoon. There is clearly a history to this problem, which I have never looked into. Your brief summary suggests that the history may be extensive... to which my response is "yikes."

In any event, you're right that "it's all water" or the alternate, "it's water, fire, earth, or air" were reasonably valid at the time. They fit the currently available information, and didn't conflict with other information. When conflicting information was found, though, people had to change their thinking. So, these might have been "the best explanations at the time," even if we can now show where the errors were.

Should a description precede the explanation? At some level, it must--otherwise, there's nothing to explain. But, once you've made the first-level explanation (e.g. it's all water), all subsequent explanations automatically have "some description" behind them. So it is with evolution. Fossils, for instance, were said by Aristotle to be trapped stars. OK. The explanation has been refined since then. We now are working on refining it still further.

We are also working on adding more detail to the description of the phenomenon.

I think I see, from this discussion, that whatever evidence people have, they will try to explain it. In the early days of philosophy, it was OK to explain things without testing the explanations to see if they made sense. We now test our explanations, both experimentally, and by comparison with other knowledge, so we think we're closer to the real story. I guess it's the testing that represents the assessment-of-validity for an explanation.

So, we are at the point of having "as much description as we can get." We want to explain the processes that led to what we have described. We have proposed explanations. Over the years, the explanations have been refined (we no longer think "it's all water" is valid).

Is it fair to say that a "description" is never an "explanation"? Or do we imagine that, as explanation and description become more detailed, they asymptotically approach one another, and in the limit, are the same?

Hmmm...maybe not. For example, this is the description of a phenomenon:

...and this is the explanation:

In any event, we have a very extensive description of a lot of stuff, as micatala has pointed out (fossils, genetics, geology, etc etc etc). We have pretty good explanations--in fact, we have one general explanation that ties it all together in a really simple and elegant way. We don't have a description of everything that took place in the history of the earth, however.

Are creationists saying that we don't have an explanation because they equate "explanation" with "complete description"? Or, is this just a debating tactic--a bit of sleight-of-hand to sway the audience? Or, do they really believe the explanation is not valid?

Well, rigs, your brief history lesson suggests that we might want to develop our own criteria for validity, rather than rely on others. It looks like there are conflicting views; rather than quibble with other people's conflicts, let's write down something we can agree on, at least among ourselves. We could start with one or another of the descriptions you've found, of course.

Does this seem reasonable?

Post 5: Sun Feb 26, 2006 6:52 pm Post subject:

2006 Most Civil Debater · Post 6: Sun Feb 26, 2006 10:07 pm Post subject:

Another good post. I think this is going to be a good thread (by my own subjective and ad hoc criteria Wink

)

The quote on Leibniz is well-taken. An explanation that is as complicated as the phenomenon it attempts to explain is no explanation at all. A simpler explanation is in general better, but of course, the trade off is you might lose some power or some accuracy. The key is to find a simple explanation that is as accurate and as powerful as possible.

It reminds me of the history of the Copernican system.

It is interesting that one of the main reasons Copernicus developed his theory was precisely the problem of all the ad hoc adjustments that astronomers had found necessary to reconcile the Ptolemaic system with updated observations. More and more epicycles (circles upon circles) and other devices had to be employed to square the data with the theory, and even then it didn't quite work. Copernicus was a 'neo-Platonist', and felt that the 'real explanation' of how the planets worked had to be simpler and more beautiful. This seems to be the main motivation for his work (I am following Thomas Kuhn's The Copernican Revolution in much of this discussion).

Copernicus was successful in developing a system that was conceptually simpler, and it led to the great revolution in astronomy and subsequent revolution in intellectual thought. But it is worth noting that Copernicus' system was actually at first no better than the Ptolemaic with respect to accurately reflecting and predecting the orbits of the planets. He also was not able to dispense with all the epicycles, only reduce their number (because he could not free himself of the idea that orbits had to be based on circles). It's only initial redeeming features were its conceptual simplicity and its mathematical advantages. In fact, many astronomers employed Copernicus' system because it made the calculations easier, even though they did not believe it was actually true.

Despite its flaws and shortcomings, Copernicus' system did provide a valuable impetus to astronomy and science in general. It is worth noting the system was very far from complete, in that it provided no mechanism for how or why the planets circled the sun. This was partially provided by Newton 150 years later. However, even Newton allowed he did not really have any idea how gravity worked its awesome force over a distance, he was only able to precisely describe its workings mathematically.

Even today, do we really understand how gravity works? Perhaps completeness is too much to hope for in general?

2004 Most Civil Debater · Post 7: Mon Feb 27, 2006 10:07 am Post subject:

Post 8: Mon Feb 27, 2006 8:50 pm Post subject:

Atheist · Post 9: Mon Feb 27, 2006 9:48 pm Post subject:

rigadoon

2005 Best Debater · Post 10: Tue Feb 28, 2006 5:33 am Post subject: