10/23/2006

On the Darwinian explanation of the success of science

I really don't have time to post now, but I'm going to anyway. Van Fraassen writes: "I claim that the success of current scientific theories is no miracle. It is not even surprising to the scientific (Darwinian) mind. For any scientific theory is born into a life of fierce competition, a jungle red in tooth and claw. Only the successful theories survive--the ones which in fact latched on to actual regularities in nature." (Scientific Image, p.40)

James Robert Brown, in "Explaining the Success of Science" (Ratio, 1985) agrees that this Darwinian explanation can account for the first two aspects of success, but not the third:
(1) The sciences "are able to organize and unift a great variety of known phenomena.
(2) This ability to systematize the empirical data is more extensive now than it was for previous theories.
(3) A statistically significant number of novel predictions pan out; that is, our theories get more predictions right than mere guessing would allow." Brown says of (3): "Here the Darwinian analogy breaks down since most species could not survive a radical change of environment, the analogue of a novel prediction."

First a small point: I don't think a novel prediction needs to be analogized to a radical change in environment -- perhaps some should be, but it's not necessary. If an organism can handle living and reproducing in any new environment, i.e., one for which its various features were not historically adapted, then that seems a decent enough analogy to a novel prediction (which makes a prediction different from the cases the thoery was originally designed to handle). A 'radical' change in environment might precipitate a scientific revolution -- i.e., the science (like the organism) might not survive.

Now, a more substantive point, and one which perhaps pushes the analogy farther than is fair. The paleobiologist David Jablonski has shown that genera that are more geographically widespread are more likely to survive mass extinction events (such as the meteor that killed off lots of the dinosaurs). The analogy would be, I suppose, to groups of related theories that 'organize and unify' a greater variety of phenomena -- which are precisely the groups of theories that we (including van Fraassen) count as most successful. So it appears that a van Fraassenite Darwinian has a nice answer to J.R. Brown: viz., the more successful groups of theories will be more likely to deliver novel predictions.

But unfortunately for the van Fraassenite, the biological story doesn't end there. What is strange about Jablonski's results is that a species' being geographically widespread has no statistical correlation with its probability of surviving a mass extinction event. The correlation only appears at the level of genera. (Side note: For the philosophers and biologists who think about group selection, this looks like an instance of it.) So, the analogy would go, the more unifying particular theories do not enjoy any advantage in novel prediction over the less unifying, but the more unifying groups of theories would. Hopefully you can see why I suggested that this may be pushing the analogy too far: I'm not sure there's anything in the domain of science that would correspond nicely to the concepts of genus and species in the evolutionary domain. Although (and now I'm really stretching), if one could be made out, perhaps the structural realists could cash out their notion of structure at the level of the genus, and thereby capture why particular theories come and go, but the structure tends to survive through revolutions.

p.s. -- Can anyone recommend a good article completely devoted to arguing for or against this Darwinian explanation of science's success? I've seen several parts of book chapters or parts of papers dealing with it, but I can't recall seeing a fine-tooth-comb analysis of it.

Labels: ,

6 Comments:

At 10/11/06, Anonymous jordan delange said...

Isn't the real problem for the van fraasen-type explanation for the success of science is that it doesn't explain why theory a is more successful than theory b? It explains, perhaps, why we have successful theories generally, but not why our specific theories are succesful, right?

Perhaps the analogues in science to the genus/species are something like "model, hypothesis/theory"? There can be some general model that attempts to explain what is going on, and a fair amount of different hypothesis that assign different values to different variables in the model that can specifically be refuted or adopted?

 
At 13/11/06, Blogger GF-A said...

Hi Jordan --

Thanks for stopping by. You may very well be right that the vF picture cannot account for why one theory meets Brown's (1)-(3) to a greater degree than another theory. (I think Peter Lipton may consider something like this line of thought in the chapter of his Inference to the Best Explanation where he discusses the abductive argument for scientific realism.) However, if I wanted to defend vF, I could say a couple of things:
(1) The reason one theory is more successful than another is just that the one is more empirically adequate than the other. If you accept that as an explanation of the success of a single theory, why not for its comparative success as well?
(2) If we take the Darwinian analogy seriously, your point has less bite. For there is nothing in the Darwinian theory of evolution by natural selection that says WHY there is differential fitness between two groups of organisms - that is, the theory by itself does not say that having sharper teeth or stronger legs or a bigger brain etc. will confer differential fitness on their bearers. And if you are willing to let Darwinian theory leave that (i.e., the cause of differential fitness) unexplained, then you should let the van Fraassenite leave it unexplained too.

 
At 14/11/06, Anonymous Anonymous said...

Why must successful theories be "the ones which in fact latched on to actual regularities in nature"?

Isn't latching on to the actual a metaphor for correspondence, and therefore, isn't the claim that the successful theories are the true ones? But why should truth have anything to do with success?

That question is one I would like to pose to Dennett concerning his memes. Doesn't Dennett's position look similar to Van Fraassen's in this regard, viz., that both are comparing thoughts or systems of thoughts to organisms?

But if the biological standard of success is reproduction, shouldn't that be the standard of success for thoughts or systems of thoughts (e.g., thoeries)? Surely there are many false thoughts that are nonetheless very successful at propogating themselves.

 
At 14/11/06, Anonymous Anonymous said...

Dr. Frost-Arnold

Sorry I did not see your comment until now. First, I'm only a grad student, and second I actually think I accept a mostly van-Fraasian account of the success of science but don't really have clear intuitions on your pushing the darwinian analogy into specifically biological terms.

That said,

1) Yes, I think this is/was more or less Lipton's view in IBE. Again, I think he (might) say to your first point that whether one theory is more empirically adequate than another is a fact. However, I think he might say that just this fact is what we need to explain: what about the first theory makes it more empirically adequate than the second? Isn't it the need for this explanation that motivates his scientific realism? In other words: the "best explanation" for why a particular theory is empirically successful is that it is approximately true?

2) Like I said, my intuitions are less clear when you push the analogy into darwinism-as-biology territory (ironically). It is true that the darwinian theory of evology requires a "context" - environment? - along with the physical traits of each species to explain relative fitness. Could there be some context that an anti-van-fraasen type could specify that would also let them demand an explanation for the success of scientific theories?

 
At 5/12/06, Blogger John Wilkins said...

You will find this has been expounded in very great detail in:

Hull, D. L. (1988). Science as a process: an evolutionary account of the social and conceptual development of science. Chicago, University of Chicago Press.

It's not a new idea - Alexander Bain and Thomas Huxley both suggested it back in the 1860s, and of course Popper also had something to say about it.

As to criticisms, attacks on evolutionary epistemology, back in the 70s and 80s focussed on the lack of normativity in EE accounts, but as Hull is doing what he calls "descriptive epistemology" that's not an issue.

Email me and I can give you scores of references to articles and books.

 
At 6/12/06, Blogger GF-A said...

Hi John W. --

Thanks for stopping by the blog, and for offering a helping hand.

I'm actually pretty familiar with Hull's Science as a Social Process (and with Philip Kitcher's work in a similar vein, esp. his Advancement of Science). They're not really addressing the question I'm asking here, though: as I understand Hull, the aim of the project is to give an evolutionary account of theoretical and conceptual change in science, and that the realism/ antirealism issue was not addressed directly. I went back and checked my copy of Science as a Social Process to check to see if I had overlooked something, but Hull even says there that he doesn't have much patience and/or see much use for the realism/ antirealism debate (see esp. p.468) -- which is what I'm asking about in this post.

And keep up the good work on Evolving Thoughts -- I appreciate the enlightenment!

 

Post a Comment

Links to this post:

Create a Link

<< Home