The Linguist’s Tale 41

The Demise of Definitions, Part I:
The Linguist’s Tale
Certain matters would appear to get carried certain distances whether one
wishes them to or not, unfortunately.
—David Markham, Wittgenstein’s Mistress
Proposition 3 says, moreover, that to think the content brown cow is, inter
alia, to think the concept BROWN, and that would be false if the mental
representation that expresses brown cow is atomic; like, for example,
BROWNCOW.
What about 4? Here again there is a way of reading what’s being
claimed that makes it merely truistic: viz. by not distinguishing concept
identity from content identity. It’s not, I suppose, unreasonable (for the
present illustrative purposes, I don’t care whether it’s true) to claim that the
content bachelor and the content unmarried man are one and the same.
For example, if concepts express properties, then it’s not unreasonable to
suppose that BACHELOR and UNMARRIED MAN express the same
property. If so, and if one doesn’t distinguish between content identity
and concept identity, then of course it follows that you can’t think
BACHELOR without thinking UNMARRIED (unless you can think
UNMARRIED MAN without thinking UNMARRIED.Which let’s just
concede that you can’t).1
However, since we are distinguishing content identity from concept
identity, we’re not going to read 4 that way. Remember that RTM is in
force, and RTM says that to each tokening of a mental state with the
content so-and-so there corresponds a tokening of a mental representation
with the content so-and-so. In saying this, RTM explicitly means to leave
open the possibility that different (that is, type distinct) mental
representations might correspond to the same content; hence the analogy
between mental representations and modes of presentation that I stressed
in Chapter 2. In the present case, the concession that being a bachelor and
being an unmarried man are the same thing is meant to leave open the
question whether BACHELOR and UNMARRIED MAN are the same
concept.
RTM also says that (infinitely many, but not all) mental representations
have constituent structure; in particular that there are both complex
The Linguist’s Tale 41
1 It will help the reader to keep the uses distinct from the mentions, to bear in mind that
the expressions appearing in caps. (e.g. ‘BACHELOR’) are names, rather than structural
descriptions, of mental representations. I thus mean to leave it open that the MR that
‘BACHELOR’ names might be structurally complex; for example, it might have as
constituents the MRs that ‘UNMARRIED’ and ‘MAN’ name. By contrast, it’s stipulative
that no formula is a structural description of a mental representation unless it contains
names of the MR’s constituents. The issues we’ll be concerned with can often be phrased
either by asking about the structure of mental representations or about the structural
descriptions of mental representations. In practice, I’ll go back and forth between the two.
The claim that concepts are definitions can be sharpened in light of these remarks.
Strictly speaking, it’s that the definiens is the structural description of the definiendum; for
example, ‘UNMARRIED MAN’ is the structural description of the concept BACHELOR.
mental representations and primitive mental representations, and that the
former have the latter as proper parts. We are now in a position to make
expository hay out of this assumption; we can rephrase the claim that is
currently before the house as:
5. The M(ental) R(epresentation) UNMARRIED, which is a constituent
of the MR UNMARRIED MAN, is likewise a constituent
of the MR BACHELOR.
Here’s a standard view: the concept BACHELOR is expressed by the word
“bachelor”, and the word “bachelor” is definable; it means the same as
the phrase “unmarried man”. In the usual case, the mental representation
that corresponds to a concept that corresponds to a definable word is
complex: in particular, the mental representation that corresponds to a
definable word usually has the same constituent structure as the mental
representation that corresponds to its definition. So, according to the
present proposal, the constituent structure of the mental representation
BACHELOR is something like ‘UNMARRIED MAN’.
The thesis that definition plays an important role in the theory of
mental representation will be the main concern in this chapter and the
next. According to that view, many mental representations work the way
we’ve just supposed that BACHELOR does. That is, they correspond to
concepts that are expressed by definable words, and they are themselves
structurally complex. This thesis is, to put it mildly, very tendentious. In
order for it to be true, it must turn out that there are many definable words;
and it must turn out, in many cases, that the MRs that correspond to these
definable words are structurally complex. I’m going to argue that it
doesn’t, in fact, turn out in either of those ways.2
One last preliminary, and then we’ll be ready to go. If there are no
definable words, then, of course, there are no complex mental representations
that correspond to them. But it doesn’t follow that if there are
many complex mental representations, then lots of words are definable.
In fact, I take it that the view now favoured in both philosophy and
cognitive science is that most words aren’t definable but do correspond to
42 The Demise of Definitions, Part I
2 It’s common ground that—idioms excepted—MRs that correspond to phrases (for
example, the one that corresponds to “brown cow”) are typically structurally complex, so
I’ve framed the definition theory as a thesis about the MRs of concepts that are expressed
by lexical items. But, of course, this way of putting it relativizes the issue to the choice of a
reference language. Couldn’t it be that the very same concept that is expressed by a single
word in English gets expressed by a phrase in Bantu, or vice versa? Notice, however, that this
could happen only if the English word in question is definable; viz. definable in Bantu. Since
it’s going to be part of my story that most words are undefinable—not just undefinable in
the language that contains them, but undefinable tout court—I’m committed to claiming
that this sort of case can’t arise (very often). The issue is, of course, empirical. So be it.
complex MRs (to something like prototypes or exemplars). Since the case
against definitions isn’t ipso facto a case against complex mental
representations, I propose the following expository strategy. In this chapter
and the next, I argue that concepts aren’t definitions even if lots of mental
representations are complex. Chapter 5 will argue that there are (practically)
no complex mental representations at all, definitional or otherwise.3
At that point, atomism will be the option of last resort.
If we thus set aside, for the moment, all considerations that don’t
distinguish the claim that mental representations are typically definitional
from the weaker claim that mental representations are typically complex,
what arguments have we left to attend to? There are two kinds: the more
or less empirical ones and the more or less philosophical ones. The
empirical ones turn on data that are supposed to show that the mental
representations that correspond to definable words are, very often and
simply as a matter of fact, identical to the mental representations that
correspond to phrases that define the words. The philosophical ones are
supposed to show that we need mental representations to be definitions
because nothing else will account for our intuitions of conceptual
connectedness, analyticity, a prioricity, and the like. My plan is to devote
the rest of this chapter to the empirical arguments and all of Chapter 4 to
the philosophical arguments. You will be unsurprised to hear what my
unbiased and judicious conclusion is going to be. My unbiased and
judicious conclusion is going to be that neither the philosophical nor the
empirical arguments for definitions are any damned good.
So, then, to business.
Almost everybody used to think that concepts are definitions; hence
that having a concept is being prepared to draw (or otherwise
acknowledge) the inferences that define it. Prima facie, there’s much to be
said for this view. In particular, definitions seem to have a decent chance
of satisfying all five of the ‘non-negotiable’ conditions which Chapter 2
said that concepts have to meet. If the meaning-constitutive inferences are
the defining ones, then it appears that:
—Definitions can be mental particulars if any concepts can.Whatever
the definition of ‘bachelor’ is, it has the same ontological status as the
mental representation that you entertain when you think unmarried man.
That there is such a mental representation is a claim to which RTM is, of
course, independently committed.
—Semantic evaluability is assured; since all inferences are semantically
The Linguist’s Tale 43
3 i.e. there are no complex mental representations other than those that correspond to
concepts that are expressed by phrases; see the preceding footnote. From now on, I’ll take
this caveat for granted.