Do frogs snap at flies or black dots? In the early part of a paper called Against Darwinism, Jerry Fodor argues that natural selection cannot account for intentional qualities of mind, i.e the way in which mental states can be about something. I find this argument intriguing in its substance but misguided in its conclusions.
It goes like this. Since natural selection is only concerned with behaviour, it can’t distinguish between different intentional states that cause identical behaviour (different in the sense that they have different content). So if, for example, having beliefs about A and having beliefs about B both result in the same fitness-enhancing behavior, it doesn’t make any sense to ask which of these beliefs is selected for. Frog-snapping is the example Fodor gives:
A mechanism that’s selected for catching flies is not ipso facto a mechanism that’s selected for catching ambient black nuisances; not even if, either in this part of the woods or in general, all and only the ambient black nuisances are flies. This logical quirk distinguishes `selection for’ from mere selection. If you select a mechanism that catches Xs, and if the Xs are Ys, then you thereby, select a mechanism that catches Ys.
Whether or not frogs really do possess fully-fledged intentional states is beside the point. The point Fodor wishes to make is that natural selection underdetermines intentional content, and hence that an account of intentionality cannot be framed solely in terms of natural selection. He thinks there really is something which needs accounting for here:
Now, intentions-to-act have intentional objects, which may serve to distinguish among them. A frog’s intention to catch a fly, for example, is an intention to catch a fly, and is ipso facto distinct from, say, the frog’s intention to sun itself on the leaf of a lily.
Fodor wants to say that there is a fact of the matter about what the frog is snapping at (where this is meant as a statement about the frog’s mental state, as opposed to its behaviour), and hence that there are features of the frog’s mind which cannot be explained by natural selection alone.
It’s hard to argue with the underdeterminism of intentional states by natural selection (aka the ‘disjunction problem’), and I see no reason why we would want to. Fodor is right to point out that natural selection is not itself intentional, and that it can’t ‘choose’ between different intentional states which show up no behavioural variation.
What I do find odd is Fodor’s insistence that there must always be a clear-cut answer to the question of what the intentional object of an intentional state is. In the frog’s intention-to-act, I see no reason why we should have to say it’s snapping at flies, or snapping at black dots specifically. It may make more sense to just say it is snapping at some abstract variable which makes no particular referential commitments – something like potential food here.
Following this line of thought does have some alarming consequences, and this is what makes the disjunction problem interesting. We’re used to talking in terms of clear intentional content – we have beliefs about Xs, fears about Ys, etc. – but the present considerations warn us that there may be situations in which this sort of talk is inherently ambiguous.
The lesson to take from Fodor’s argument is not that there is some mysterious aspect of mind whose presence natural selection cannot explain, but that we should be careful about interpreting this aspect naïvely. In this sense the disjunction problem is not a ‘problem’ for evolutionary accounts of mind at all – it is another piece in the infernal jigsaw of working out what this thing we’re trying to account for even is in the first place.
The Platopus 