I was trying to figure out what Fodor could have been thinking. Here’s what I came up with:
- If we are trying to figure out what Evolution has done, then we presuppose that Evolution is capable of doing something.
- If Evolution is capable of doing something, then there must be some mechanism of Evolution that does the doing.
Now imagine yourself in the position of the mechanism of Evolution that does the doing, i.e. the mechanism that selects the traits that yield a higher fitness.
The question becomes: is it possible for you to select for a trait?
The answer is NO.
To understand why, consider what happens when we try to give an evolutionary explanation of something: we are beset by a near infinite selection of different possibilities. Only through careful study can we narrow down which traits are actually the ones that increase an organism’s fitness and, if we are in a historical context, only give a most likely candidate for such a trait.
Now imagine yourself back in the position of the mechanism. The mechanism is stuck with the exact same sort of problem that we have when trying to figure out what it has done: it has no more an ability to select a single trait than we have to figure out which trait it has selected with our first guess. Whenever it tries to select for a trait, it may mistakenly also select for another trait that is not so good for the organism, or it may not have even recognized the trait it thought it was selecting for.
Therefore, since this mechanism can’t work, evolution is bunk.
OK. Now let’s take a step back and look at this argument. Basically there are two parts: the first part is an argument that there is a mechanism that does the doing and the second part says the mechanism can’t have done anything. When I saw Fodor speak on this topic, I believe (it was a while ago now) he spent a good deal of time on arguing for the first part and I didn’t really understand what he was up to. Now it makes sense because if we accept that there is some mechanism that does the doing, then we may be committed to admitting to at least some amount of skepticism about evolution based upon the second part. Getting even some skepticism about evolution would be a sufficiently large accomplishment, and so I figure this must be Fodor’s ultimate goal.
In light of this argument I offer this wild conjecture for your reading pleasure:
Replace “mechanism” with “agent”. Now, instead of an argument against evolution, it is an argument against Intelligent Design. Intelligent Design has the designer/ agent built directly into it, and this makes the argument much more knock-down: There is no need to argue for the existence of a mechanism because it is right in the title, and since the intelligence of ID is something like our intelligence, it makes sense that it would suffer from the same problems that ours does.
What I think happened is that Fodor was sitting around thinking why intelligent design doesn’t work and realized that if he could make a strong enough argument that evolution also required some sort of agent, in the form of an evolutionary mechanism, then he could return a similar result. Since having a technical reason for discounting ID wouldn’t make much of splash, Fodor dropped the argument against ID and pursued the argument against evolution.
Personally I kind of like this argument against ID. If I ever run into some ID people, I may even bring it up.