THE “FUNCTIONAL KINDS” OBJECTION

1 THE “FUNCTIONAL KINDS” OBJECTION

This objection proceeds from the not implausible conjecture that the taxonomy of psychological kinds embedded in FP is most accurately construed as a taxonomy of functional kinds rather than of genuinely natural kinds. It is then pointed out, quite correctly, that the ontological integrity of functional kinds— such as chair, mousetrap or bungalow—is not contingent on their finding a smooth intertheoretic reduction to some natural science of the underlying substrate (because the relevant functional properties might be realizable in a variety of substrates with a variety of dynamical resources). The conclusion is then drawn that FP has nothing to fear from any future failure to find a smooth explanatory reduction within, say, computational neuroscience. The principle, “Reduce, or be eliminated,” on which EM is said to rest, is rejected as unacceptable.

One will find straightforward versions of this objection in Putnam (1988) and Searle (1992). It is a popular objection and it is sufficiently obvious that my original 1981 paper on EM addressed it at some length showing the ease of constructing a parallel “vindication” of the dear departed Alchemical Kinds). I stand by that original response, but let me here try a more direct approach.

In fact, the case for EM rests on no such overblown principle as “Reduce, or

be eliminated,” at least if this is interpreted as a demand for a type-type reduction. Such a draconian principle would banish all functional kinds at once. But the defender of EM is neither ignorant of nor hostile to the existence of functional kinds. The worry is not that FP kinds are too much like the (legitimately functional) kinds chair and bungalow, the worry is that FP kinds are too much like the (genuinely uninstantiated) kinds phlogiston and caloric fluid.

The primary worry, in other words, is that FP is a radically false representation of the kinematical and dynamical reality within each of us. One relevant symptom of FP’s radical falsity would be its inevitable failure to find even a rough or disjunctive reduction within an explanatorily superior neuroscientific successor

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constitute a serious empirical case against FP, as they might against any other theory. That case will have to be evaluated as a whole, with the matter of reductive relations to neuroscience (or their absence) being but one very important part of it. Focusing our attention on the ontological status of chairs and bungalows simply deflects our attention away from the need and the obligation to pursue that broad empirical evaluation of FP. And it misrepresents the rationale behind EM.

It misleads in a further respect. The physical tokens of any functional kind are typically manufactured to meet our functional specifications and typically there is no intelligible question of whether our functional concept is adequate to the behavioral reality the manufactured object displays. No one feels a need to evaluate our concept paring knife, for example, in order to see if it lives up to the structural and behavioral reality of real paring knives. The onus of match is entirely in the other direction. Casting FP kinds as functional kinds implicitly portrays them as having a similar “authority” and empirical “invulnerability.”

But human beings and animals are not artifacts. We are natural objects. Accordingly, while our internal economy may indeed be an abstract, highlevel functional economy, realizable in many other substrates, it remains a wholly empirical question whether our current FP conception of that internal economy is an accurate representation of its real structure . Let us agree then that FP kinds are abstractly functional. This changes the situation in no relevant way. The issue of their collective descriptive integrity must still be addressed. The objection from functional kinds, as outlined above, is just a smoke screen that obscures our continuing obligation to evaluate the empirical integrity of FP and to compare its virtues and failings with competing representations of what cognitive activity consists in. It cannot serve as a defense of FP against real or prospective empirical criticisms.