Tag Archives: Fodor

Hypotheses Natura Non Fingo

Newton famously wrote [1] [2]:

I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses…  It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.

as a response to those who challenged him to provide causes of gravity.  He said, “Hypotheses non fingo,” or, “I feign no hypothesis,” or if you will, “I haven’t even a guess.”

Earlier in a letter he wrote:

That one body may act upon another at a distance through a vacuum without the mediation of anything else, by and through which their action and force may be conveyed from one another, is to me so great an absurdity that, I believe, no man who has in philosophic matters a competent faculty of thinking could ever fall into it.

These passages show that Newton recognized a fundamental causal problem within his theory: that although his mathematics described gravitational physics, it did not provide a causal explanation.  It was not until General Relativity 200 years later was this problem solved.

Recently another major fundamental theory of science has been accused of lacking the proper causal structure:  Fodor & Piatelli-Palmarini’s attack on evolution, What Darwin Got Wrong.  Consider what Fodor says in his recent reply to Block and Kitcher,

A mere chronicle of instances of adaptation would not therefore amount to a theory of adaptation. It would just be “natural history.” We haven’t the slightest doubt that Darwin thought that he had discovered a theory of adaptation. It was, to be sure, a pretty thin theory, as it would have to be in order to apply to evolving creatures as such, whatever their phenotypes and whatever their ecologies.

He is saying that evolution is a mere chronicle of natural history — not a cause of it — just as Newton’s gravitation described gravity without revealing its causal structure.  Later he says,

[Biologists should] give up on the project of finding a mechanism for evolution and study the fixation of adaptive traits case by case. Since all the evidence suggests that they are extremely heterogeneous, this should keep evolutionary biologists busy well into the indefinite future.

This means that biologists should give up on repairing evolution and just try to explain individual phenomena moving forward, just as physics moved forward even as Newton knew his theory was on metaphysical shaky ground.

Hence it is Fodor now saying, “Hypotheses non fingo,”  because he believes he can describe natural history accurately, but also has no guess as to what caused things to work out the way they did.

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In light of this analysis, consider this statement from Block and Kitcher’s counter argument:

After our critique, Fodor and Piattelli-Palmarini have apparently decided that the crucial point is the lack of a “theory” of natural selection. But, as we have noted here, nobody needs a “theory” of the type they demand.

And this from Sober’s recent review [pdf]:

What is the net gravitational force now acting on the earth?  That depends on the mass of the sun, the moon, the stars, and of everything else.  It does not follow that there are no laws of gravity, only that the laws need to have numerous placeholders.  FP may object to my analogy because it is always the mass of these various objects and their distance from the earth that are relevant to the gravitational force that the earth experiences.  My reply is that this makes no difference…

Neither has understood the argument as presented above.  If Block and Kitcher had understood, then they would have recognized that yes, for the vast majority of people, the “‘theory’ of the type they demand” is unnecessary, but it is, nevertheless, of critical importance to the likes of Newton and Einstein.  If Sober had understood, then he wouldn’t have used the worst possible example to make his point:  by saying it is “always the mass of these various objects and their distance from the earth that are relevant,” and not mentioning motion, we know he was only thinking about Newtonian Mechanics.

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Should we, with Fodor, believe that we are stuck in a philosophical absurdity?

No.  What I said in my original criticism of Fodor, found in What Fodor Got Wrong (18 March 09),  still applies.  Though the above description of the problem is likely clearer than my analysis based on his claims that Natural Selection is statistical and that the struggle for survival is only a metaphor, the problem of causal structure is the same.  My solution focuses on using individual struggles as local interactions of Natural Selection — like a gravitational field in General Relativity — and hence provides the causal structure that Fodor wanted.

[EDIT 6 April 2010:  I’m thinking I gave Fodor too much credit in this post.  I now think his arguments amount to saying that for each instance of evolution we have, we are merely relaying natural history, not a causal explanation.  The argument I attributed to Fodor above says that evolution by natural selection is natural history.  Fodor must be more agnostic about evolution’s ontology because of how he says it is possible to look for some alternative to natural selection in his reply to Block and Kitcher.  My solution is still viable though:  since I provide causal structure, this also provides how to describe evolution in a causal way.]

Posted in biology, evolution, General Relativity, philosophy, physics, Relativity, science. Tagged with , , , , , , , .

Dismantling Fodor’s Argument

Fodor argued that the theory of evolution is not a legitimate theory of science because it is either vacuously true or wrong.  He accused Darwin of committing the intentional fallacy. (synopsis here)

Insofar as he made no logical mistakes in his reasoning, we need a different strategy to defend the theory of evolution.  In this post I will argue that his argument is an instance of gerneral underdetermination, and hence not a problem of evolution but of philosophy of science.

Underdetermination means that we can’t specifically identify the exact cause of scientific phenomena.  For example, given some phenomenon, say darkness during the day, there can be many possible explanations: an eclipse, an exploding volcano shooting ash into the air, the sun has gone out, the electric company has blocked the sun to make more money, it was the work of Claw Vipers, etc.  The exact cause of the darkness is underdetermined; sure we can research the problem and eliminate some of the possible explanations, but because of our limitations we will never be able to check everything.  So the cause of the darkness can be said to be underdetermined, i.e. there is just not enough determining evidence.

Fodor argues that the theory of evolution is vacuous becuase given any trait we identify as benficial to the fitness of the organism is arbitrarily selected.  Since there are too many factors to identify within an ecosystem or organism acting within that ecosystem, any hypothesis we propose about the fitness of that organism in that ecosystem will be trivially compatible with evolution.

For example assume there is an argument that having a certain trait, say longer legs, increases a zebra’s fitness.   We can recognize that this argument could be unfounded because it might not be the longer legs but something else that increases the zebra’s fitness.  It just happened that increased leg length was a harmless side affect of this truly beneficial trait.  Either way, if it is the longer legs or some other unidentified trait, evolution is always compatible with our theories, and so it is trivially vacuously true.

In short I would say that he is arguing the cause of natural selection is underdetermined.  The task is to identify whether this is a unique case of underdetermination or an instance of general underdetermination.  I will now show that this sort of underdetermination can exist in physics*:

Imagine we are doing physics and we want to know which of two metal ingots is the more massive.  We pull out our scale, place each object on one of the trays and wait for the scale to indicate which is the more massive.

Why does the scale tip in the direction of object A?  We could argue that object A has a trait, it is composed of iron, and that trait makes it more massive than some other object.  However, maybe object B is connected to a helium balloon.  Maybe there is a gravitational anomaly in the location where we are doing our experiment.  Maybe the iron is magnetized and there is another ingot with the opposite polarity under the table.  Maybe a God is tampering with our experiment with a noodly appendage.  Feel free to make up as many of these as you want.  There any number of reasons why one object could tip the scale in its favor, and being more massive is among them, though selecting this as the reason is arbitrary.

(One of the things that is wrong here is that we don’t expect General Relativity to predict which objects are more massive.  The mass of an object is the result of the history of its creation and ‘life’ up till the point we measure it.  We do expect Relativity to suggest methods for testing such claims, which it does.  Likewise Evolution should not be expected to predict which organism is fitter, but to suggest methods for testing fitness.)

If I now recast Fodor’s criticism into physical terms, in reference to the above thought experiment, this is the result: The theory of General Relativity (gravity) is vacuous because any given trait we identify as increasing the mass of an object is arbitrarily selected.  Since there are too many factors to identify within a physical system, any hypothesis we propose about mass of the object in that physical system will be trivially compatible with General Relativity.

Therefore physics suffers from the same kind of underdetermination that Fodor accused of evolution.  Anyone who persists in disbelieving evolution on these grounds should also deny General Relativity.  Of course this is excessive: since the underdetermination criticism goes to the heart of our scientific theories in general, it is a problem of philosophy of science and not a problem of biology or physics specifically.  Insofar as underdetermination remains an issue within the philosophy of science we still have to take it into consideration, but this should not be seen as a reason to think our current scientific theories are wrong.

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[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo]

See a continuation of the argument against Fodor in What Fodor Got Wrong, and in Fodor’s Intensional Criticism of Evolution.

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* This is the argument I presented Fodor with during our brief conversation after his talk at CUNY.  He tried to block it by saying that Natural Selection is statistical, whereas General Relativity is not.  In my previous post, What Fodor Got Wrong, I argued that this position begs the question or is just wrong.

Posted in biology, evolution, fitness, General Relativity, measurement, philosophy, physics, science. Tagged with , , , , , , , .

What Fodor Got Wrong

Jerry Fodor recently (4 March) gave a talk entitled “What Darwin Got Wrong” at the CUNY Graduate Center in New York City.  He accused Darwin of committing the intentional fallacy and hence said, straight out, that he didn’t believe in the theory of evolution.

So what exactly does Fodor think Darwin got wrong?

He believes that the theory of evolution is vacuously true (or just wrong) and hence not a worthwhile theory of science.

You can sink your teeth into the argument in this synopsis, but be forewarned, the argument is good: you may, depending upon your convictions, be forced to disbelieve the theory of evolution.  However, it doesn’t identify all the critical presuppositions that Fodor uses (this is no fault of the synopsis; it is accurate to the argument), and these are what are really necessary to show where Fodor is mistaken.

[The one day, the ONE DAY, a year that there is a talk specifically having to do with my work on philosophy of science and biology and I have an international plane flight to catch only a few hours after the talk.  I happily was able to catch the whole talk but I couldn’t stay for the question and answer session.  So I did the only thing I could think of and asked my questions during the break and ran out of the building (literally).  The following quote is accurate as far as I can remember, and, as far as I know, I am the only one who heard him say it.]

Fodor said,

“Natural Selection is statistical. It just is.”

What does this mean?

In my world Natural Selection is a force.  It is a force that changes species over time.  For example lets take some species of bacteria.  A few of the bacteria in that species adapt to be able to eat a novel sort of food and this gives them an advantage over the others.  Eventually these bacteria are able to replicate more often and eventually most of the overall bacteria population has this trait.  Hence the species has changed from not having a certain property to having a certain property.  If you ask me what caused this change in the bacteria population, I would say that Natural Selection was the cause or force behind the change in the species.

There are two ways I can think of interpreting Fodor’s statement: 1) Natural Selection is statistical and not a force.  2) Natural Selection is statistical and a force.

Taking the first interpretation that Natural Selection is statistical and not a force, how are we to understand my little story about the bacteria above?  Perhaps: “The change in the physiology of certain bacteria statistically increased their fitness over the other bacteria.  Hence those bacteria were able to replicate more readily and eventually outnumber bacteria without that trait.”  The thing that changed the species was the increased fitness, which was caused by the physiological change.  Natural Selection was the result of this change and can be observed statistically by seeing how individual organisms with that trait were able to fair better than their compatriots.  Therefore Natural Selection is a non-causal description or explanation of how species change.

This is immediately problematic because a description or explanation is always describing or explaining something that already exists: it will always be vacuously true, e.g. snow is white if(f) snow is white, or it will just be wrong, e.g. snow is blue.  Therefore, by assuming that Natural Selection is statistical and not a force, we have begged the question against Natural Selection.

Now let’s take a look at option 2: Natural Selection is statistical and a force.

As a force Natural Selection is the cause of things.  Causes can work directly, such as one object striking another and causing it to change direction, or as a field does, by creating an environmental disturbance of some sort which affects the object.  Natural Selection falls (more or less) into the latter category: the environment changes and this causes species to change, to adapt.

Is Natural Selection statistical under this interpretation? No.  If Natural Selection acts in the way a field does, by changing the environment which then affects things in that environment, then at every point there is some local interaction between the field and the object.  Otherwise we have a theory of action-at-a-distance, i.e. one thing is causing something to happen without any way for us to identify the underlying process: a theory of magic.  If something is acting statistically, then it is acting at different places with no known connection between them.  However, evolution comes with a ready made theory of local interactions: every organism is constantly struggling for survival.  The struggle for survival ensures that there is a connection between Natural Selection and the environment.  Therefore if Natural Selection is a force, it cannot also be statistical.

[I can confirm that Fodor believed that the struggle for survival was not critical because earlier in our brief conversation he said that the struggle for survival was merely a metaphor.  I responded by saying that Natural Selection is a metaphor then too, but he disagreed.]

In conclusion, by assuming that Natural Selection is statistical and ignoring the local interactions in the struggle for survival, Fodor has begged the question against evolution.  As a statistical non-causal explanation, Natural Selection cannot act as a force in evolution.  Once evolution has lost it’s driving force, it no longer can function as a working scientific theory.  However, believing that Natural Selection is a non-causal explanation is unfounded.  The theory of evolution provides a method – the struggle for survival – that explains how Natural Selection causes change in species via the environment, and ignoring this is what Fodor got wrong.

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[EDIT:  I’ve put up a new analysis (24 March 2010) of Fodor’s argument here: Hypotheses Natura Non Fingo]

See a continuation of the argument against Fodor in  Dismantling Fodor’s Argument, and in Fodor’s Intensional Criticism of Evolution.

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