Darwin at 200: Fodor and Kitcher on Natural Selection

Two hundred years after Charles Darwin’s birth – and nearly 150 since the arrival of his magnum opus, On The Origin of the Species by Means of Natural Selection – and it is difficult to sketch how the figure might respond to the modern zeitgeist.  In the United States the paradoxes are bewildering, and even more so when the fissures exist not just within the distant enclaves of Arkansas and Oklahoma, but on the ground between the most preeminent philosophers. At least two of them.

Rutgers University sponsored a debate between these philosophers, sparing on the intricacies of natural selection – and while a far cry from the disputes over Intelligent Design, conceivably no less consequential. Though I originally intended to write on some of the important implications outside the immediate contextual framework of Darwinian thought, I’ve opted to dedicate a sizable entry to the matters themselves.  However, I will likely return to this issue of contextualizing the historical moment and what it means in the future.

Out of the left corner was Rutgers’ Jerry Fodor; Fodor is fairly universally regarded as the foremost philosopher of mind, as well as leading authority in philosophy of language and cognitive science.  Counterposed to Fodor was Philip Kitcher, a philosopher of mathematics and science (among other disciplines) associated with Columbia University. Fodor pronounced his position in a decidedly philosophical slant, certainly as compared to what was to come from Kitcher. Darwin’s natural selection (N.S.) fails to exist as a scientific theory because it rests upon post-hoc analysis and can only produce results in two forms: either empty conclusions, or on the other hand, tautologies.  Though Fodor failed to succinctly clarify this particular drumbeat of his regarding tautologies, the greater corpus of his argument emerged throughout his presentation and associated rebuttal to Kitcher. It came as follows: Darwin’s N.S. depends upon the assumption there is a methodology or mechanism for the transmission of the pool of heritable traits, or phenotypes (traditionally, phenotype refers to the observable heritable traits, perhaps beside the greater point).

When we talk about coextensive traits, Fodor says, we suppose Darwin’s N.S. contains the means for determining which of these traits is chosen (and why).  It’s important to go on the record at this point: Fodor doesn’t have any significant quarrels with our phylogenies – our evolutionary family trees.  What Fodor does contest is the mechanism that (allegedly) drives this progression.  Fodor says something like the following: of course Darwin’s N.S. can explain the prevalence of this or that trait the rest are already gone. The illustrative analogy presented was, he said, borrowed from Stephen J. Gould and Richard Lewontin, published in 1979. (Gould and a separate colleague wrote a paper in ’72 that revolutionized the way we understand the timelines of morphology with a thesis of Punctuated Equilibrium which drove Darwinian Gradualism into obscurity.)  The analogy reminds us of the spandrel, a lavishly decorated triangle at the peak of dome-style churches and corners of arches. Fodor, as well as a few others (he claims), look at these as analogous to coextensive traits in biology. Was it the dome or the spandrel that was selected for, (i.e., designed around)? The beauty of the spandrel led many to believe it was the trait in mind. But was it? Fodor tells us we can find out – and easily. Just ask the architect.  Pieces of architecture, of course, have a conscious mind behind them: the human designer. As it turns out, the dome was the selected trait; the coextensive spandrel just came as a two-for-one deal. But nature doesn’t have any such mind, or access to counterfactuals. So while looking at a species that fits this mold, we wouldn’t know intrinsic mechanism, and without a mind, nature wouldn’t either. Here we have Fodor’s main blow to N.S.

In that case, what do we have when analyzing the progression of phylogenies? Fodor’s answer: a vast number of historical narratives, none of which are guided by N.S. (Perhaps there’s some other scientific phenomena, perhaps not, but that’s outside the immediate scope of inquiry for Fodor.)  The real movements and gains in scientific understanding associated with evolution take place within the disciplines that flank the Darwin’s theory: genetics, biochemistry, and so on. Specifically, he says, it’s under the microscope – not out in the field – that considerable and serious knowledge is acquired. He doesn’t like to think this can be in harmonious conjunction with N.S. theory.

Kitcher followed a pretty traditional footing on Darwin. The most important points Kitcher presented concentrated on the subtle restructuring needed within Darwinian pedagogy. We shouldn’t read Darwin anachronistically, assume more of him than reasonable or nurture a dogmatism that negatively affects our comprehension of N.S.  And if we do read Darwin accurately and fairly, we won’t run into the problems Fodor believes exist.  On the semantic and educational level, Kitcher says, we shouldn’t cling to the historical talk of N.S. moving as a “force” that “acts.” Rather, natural selection is a process that operates over time.  But, I’ll add, anyone with some education in evolution understands there’s another level beyond the locution; process is significant of the nature of N.S., it implies the timeline involved.  Simultaneously, Kitcher dedicated time to discussing the basic elements of N.S., which was invariably a result of being forced to recap the science.  As expected, Kitcher brought the Peppered Moth of industrial England into the spotlight (a classic case of N.S. at work) and shifted to evidence that has established evolution.  This is in itself a rebuttal to Fodor.  Kitcher is doing two things: explicitly, Kitcher says here are the facts of N.S., and this is their predictive power; second, and somewhat more tacitly, Kitcher implies the necessity for a shift to scientific detail even within theoretical dialogues.

Admittedly, I’ve begun to synthesize some of my own responses into Kitcher’s, which is perhaps unavoidable from one who doesn’t believe in evolution, but accepts it. Such a defense is natural. I think where Fodor lacks most glaringly (apart from a too rigidly philosophical answer to a fairly inflexible scientific inquiry) is within his jumping off point.  There need not be any historical research done to understand the depth of Darwin’s education on genetics; it simply didn’t exist in any form we respect today.  Though farmers have been able to appreciate and take advantage certain biological phenomenon associated with the 9:3:3:1 inheritance ratio (i.e., 3:1 dominant to recessive, assuming monogenic traits) Mendel uncovered, they had no sophisticated understanding beyond the blurry conception of some kind of mystical and chanced blending taking place.  Similarly, Darwin operated in absence of the more advanced genetic discoveries to come henceforth in science. Likewise, Darwin himself couldn’t explain the origin of genetic variation whatsoever: e.g., why do any of the 13 Galapagos finches (or, more accurately, their forebears) begin with varied traits that may or may not be favorable to the varying ecologies?  This is the crucial juncture of Kitcher, representing the Darwinian tradition, and Fodor. As mentioned, Kitcher concentrates on the notion that N.S. isn’t a “force” that “acts” but an ongoing process. “Random” variation is only random insofar as it exists outside the ecological needs of the species. This I’ll certainly take stock in.  It appears as if Fodor depends upon a straw-man conception of Darwin, focusing on Darwin’s own personal lack of genetic knowledge to attack the modern conception of N.S., (and he still doesn’t do it successfully, I want to demonstrate).  This is all despite his admission the accompanying sciences make sizable contributions to evolutionary theory (in his mind, disharmoniously with N.S.).  Finally, it ignores the words of Kitcher, suggesting we interpret Darwin as a schema and foundation rather than a book published in 1859 that acts as an infinite reservoir of answers.

But to thoroughly dispel Fodor’s attack on N.S., let’s apply the principle of charity and assume the bulk of what Fodor says regarding the inheritance of phenotypes is true; there’s no mechanism for it, no means of discrimination, and we’re completely stumped by species with coextensive traits. So say Species A is at time t producing offspring with coextensive traits in general disregard to the ecology. Like it or not, each of these traits varies within a certain range in the population, due to mutations or gene flow. If a pressure begins to push against one of these coextensive traits, some kind of selection will occur. By time t` one trait might have disappeared and the other may have thrived. Or, if it’s crucial to the degree an arch is to a spandrel (though unlikely), species do become extinct.  It’s certainly a possibility.  A field study can likely illustrate the different levels of success in coping with selective agents, and accordingly, reproducing. The individuals with better success are going to produce offspring in accordance to Mendelian ratios or a polygenic bell curve: either way a more significant statistical genetic contribution. Thus begins descent with modification.

Though Fodor is attacking the principle of N.S. for operating as if it had a mind, it seems he more than anybody else wants it to have a mind.  He is of course a philosopher of mind, unironically.

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