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that are presumed to be previously understood. It is, to put it mildly, hard to
see how this could work if introducing a new concept into a theory ipso
facto changes what all the old terms mean. For then the expressions by
reference to which the neologism is introduced aren t  previously
understood after all: they are just homophones of the previously
understood expressions.22
Consider, for a familiar example, the introduction by implicit definition
of a logical constant like  ("  . The idea is that to determine that  ("  has the
same sense as the (truth conditional, inclusive) English  or , it s sufficient
to stipulate that:
P ’! P (" Q
(P (" Q) & ~P ’! Q
But the plausibility of claiming that these stipulations determine that  (" 
means  or depends on supposing that they preserve the standard
interpretations of  & (= conjunction),  ~ (= negation), and  ’!  (= truth-
functional implication). That, however, implies that the interpretation of
 & ,  ~ , and  ’!  must be assumed to be isolated from whatever meaning
changes adding  ("  to the host theory is supposed to bring about; an
assumption that is contrary, apparently, to the holist thesis that the
semantic effects of theory change reverberate throughout the vocabulary
of the theory. (I say that it s  apparently contrary to the holist thesis
because I know of no formulation of semantic holism that is precise
enough to yield unequivocal entailments about which changes of theory
effect which changes of meaning.)
22
This point is related, but not identical, to the familiar worry about whether implicit
definition can effect a  qualitative change in a theory s expressive power: the worry that
definitions (implicit or otherwise) can only introduce concepts whose contents are already
expressible by the host theory. (For discussion, see Fodor 1975.) It looks to me that implicit
definition is specially problematic for meaning holists even if it s granted that an implicit
definition can (somehow) extend the host theory s expressive power.
Chaps. 5 & 6 11/3/97 1:10 PM Page 116
116 Prototypes and Compositionality
This isn t just a technical problem; texts that flout it tend to defy
coherent exegesis. Consider, for one example among very many, Gopnik s
suggestion23 that
An  object is a theoretical entity which explains sequences of what (for lack of a
better term) we might call object-appearances at the evidential level . . . At the very
earliest stage infants seem to have a few rules about the relations between their own
actions and object-appearances, for example, infants seem to know that objects
disappear when you turn away from them and reappear when you turn back to
them. (1988: 205)
(and so forth, mutatis mutandis, for further  rules that the child gets later).
How are we to interpret this passage? Notice the tell-tale aporia (where
are you, Jacques Derrida, now that we need you?). The rule with which the
infants are credited is said to be about  relations between their own actions
and object-appearances (my emphasis). But, when an instance of such a
rule is offered, it turns out to be that  objects [my emphasis] disappear
when you turn away from them . Question: what does  objects mean in
this rule? In particular, what does it mean to the infant who, we re
supposing, learns the concept OBJECT by a process that involves
formulating and adopting the rule?24 If it means object-appearances, then
(quite aside from traditional worries about how an appearance could
reappear) it doesn t do what Gopnik wants; since it specifies a relation
among object-appearances, it doesn t give the infant information about
the relation between objects and object-appearances.
So, maybe  object means theoretical entity which explains sequences of
what (for lack of a better term) we might call object-appearances at the
evidential level. I rush past the implausibility of claiming that infants have
to have that much ontology (in particular, that much dubious ontology) in
order to learn quotidian object-concepts like CHAIR. I m a nativist too,
after all. The more pressing problem for a theory theorist is: if that s what
 object means in the infant s rule, in what sense are there discontinuities in
the development of the infant s object-concept ? On this reading of the text,
it looks like what the infant has right from the start and right to the
finish is a concept of an object that s much like Locke s: objects are
unobservable kinds of things that cause experiences. Correspondingly,
cognitive development consists of learning more and more about things of
23
I don t particularly mean to pick on Gopnik; the cognitive science literature is full of [ Pobierz całość w formacie PDF ]