The content of the post that follows was first published in roughly this form in Biolinguistics. I put it up here for obvious reasons. Jerry Fodor was a great philosopher. I knew him personally but not as well as many of my friends did. I was charmed the few times I socially interacted with him. He was so full of life, so iconoclastic, so funny and so generous (most of his insights he graciously attributed to his grandmother!). I looked up how often I talked about Jerry's stuff on FoL and re-reading these made me appreciate how much my own thinking largely followed his (though less funny and less incisive). So, he will be missed.
So, without further ado, here is a reprise of what I take to have been the Jerry/Massimo argument against Natural Selection accounts of evolution.
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Jerry Fodor and Massimo Piatelli-Palmarini (F&P, 2010) have recently
argued (in What Darwin Got Wrong) that
the theory of Natural Selection (NS) fails to explain how evolution
occurs. Their argument is not with the
fact of evolution but with the common claim that NS provides a causal mechanism
for this fact. Their claim has been
greeted with considerable skepticism, if not outright hostility.[1] Despite the rhetorical heat of much of the
discussion, I do not believe that critics have generally engaged the argument
that F&P have actually presented. It
is clear that the validity of F&P’s argument is of interest to
biolinguists. Indeed, there has been
much discussion concerning the evolution of the Faculty of Language and what
this implies for the structure of Universal Grammar. To facilitate evaluation of F&P’s
proposal, the following attempts to sketch a reconstruction of their argument
that, to my knowledge, has not been considered.
1. 'Select' is not 'select for', the latter being intensional.[2]
2. The free rider problem shows that NS per se does not have
the theoretical resources to distinguish between ‘select’ and ‘select for.’
3. If not, then how can NS causally explain evolutionary change?
4. There are two ways of circumventing the free rider problem.[3]
a.
Attribute mental powers to NS, i.e. NS as Mother Nature,
thereby endowing NS with intentionality and so the wherewithal to distinguish
‘select’ from ‘select for.’
b.
Find within NS Law supporting counterfactuals, i.e.
Laws of Natural Selection/Evolution, which also would suffice to provide the
requisite intentionality.
5. The first option is clearly nuts, so NS accounts must be presupposing
4b.
6. But NS contains no laws of evolution, a fact that seems to be widely
recognized!
7. So NS can't do what it purports to do; give a causal theory that
explains the facts of evolution.
8. Importantly, NS fails not
because causal accounts cannot be given for individual
cases of evolution. They can be and routinely are. Rather the accounts are
individual causal scenarios, natural histories specific to the case at hand,
and there is nothing in common across the mechanisms invoked by these individual
accounts besides the fact that they end with winners and losers. This is, in
fact, often acknowledged. The only relevant question then is whether NS
might contain laws of NS/Evolution? F&P argue that NS does not
contain within itself such laws and that given the main lines of the theory, it
is very unlikely that any could be developed.
9. Interestingly, this gap/(flaw) in NS is now often remarked in the Biology
Literature. F&P review sample some work of this sort in the book. The
research they review tends to have a common form in that it explores a variety
of structural constraints that were they operative would circumscribe the
possible choices NS faces. However, importantly, the mechanisms proposed are
exogenous to NS; they can be added to it but do not follow from it.
10. If these kinds of proposals succeed then they could be combined with
NS to provide a causal theory of evolution. However, this would require giving
up the claim that NS explains evolution.
Rather, at most, NS + Structural
Theories together explain evolutionary change.[4]
11. But, were such accounts to develop the explanatory weight of the
combined 'NS + Structural Theory' account would be carried by the added structural
constraints not NS. In other words, all that is missing from NS is that part
that can give it causal heft and though this could be added to NS, NS itself
does not contain the resources to develop such a theory on its own. Critics might then conclude as follows: this
means that NS can give causal accounts when supplemented in the ways
indicated. However, this is quite
tendentious. It is like saying Newton's
theory suffices to account for electro-magnetic effects for after all Newton's
laws can be added to Maxwell's to give an account of EM phenomena!
12. F&P make one additional point of interest to linguists. Their review and conclusions concerning NS
are not really surprising for NS replays the history of empiricist psychology,
though strictly speaking, the latter was less nutty than NS for empiricists had
a way of distinguishing intentional from non-intentional as minds are just the
sorts of things that are inherently intentional. In other words, though attributing mental
intentional powers to NS (i.e. Mother Nature) is silly, attributing such powers
to humans is not.
This is the argument. To be honest, it strikes me as pretty
powerful if correct and it does indeed look very similar to early debates
between rationalist and empiricist approaches to cognition. However, my present intention has not been to
defend the argument, but to lay it out given that much of the criticism against
the F&P book seems to have misconstrued what they were saying.
[1] See,
for example: A misguided attack on
evolution, Massimo Pigliucci. 2010. Nature 464, A misunderstanding Darwin, Ned Block and Philip Kitcher. 2010. Boston
Review of Books, 35(2), Futuyma, D. 2010, Two
critics without a clue. Science, 328: 692-93.
[2]
Intensional contexts are ones in which extensionally identical expressions are
not freely interchangeable. Thus, if
John hopes to kiss Mary and Mary is The Queen of the Night, we cannot conclude
that John hopes to kiss the Queen of the Night.
[3]
F&PP develop this argument in Chapter 6.
The classic locus of the problem is S.J. Gould and R.C. Lewontin. The
spandrels of San Marco and the Panglossian paradigm: a critique of the
adaptationist program. Proceedings of
the Royal Society of London, Series B biological sciences, vol 205, 1979,
581-98.
[4] Observe, the supposition that selection is simply
a function of “external” environmental factors lies behind the standard claim
that NS (and NS alone) explains why evolutionary changes are generally
adaptive. Adding structural “internal”
constraints to the selective mix, weakens the force of this explanation. To the degree that the internal structural
factors constrain the domain of selection, to that degree the classical explanation
for the adaptive fit between organism and environment fails.
