Ambiguous contents?
Arvid Båve, Higher seminar in
Theoretical Philosophy, FLoV,
Gothenburg University, 8 May 2013
Last time, I gave an argument for:
(7) The LFC of ”All Fs are G” is the same as that of
”a is F”
To say that the LFC of sentences S and S’ are the
same is to say that the propositions they express
have the same syntactic structure.
(7) thus entails that there is a syntactic category
at the level of thought including both quantifiers
everything, every F, some F, etc., and individual
concepts like Aristotle, etc.
(7) is just an expression of a common stance in
contemporary linguistics, according to which it
was wrong to suggest that sentences with the
same surface grammars have ”different logical
forms”.
Focussing now on the present, specific sense of
logical form, however, we can see that a
potential problem involving structural ambiguity
immediately arises for (7).
Objection against (7):
(a) ”Everyone greets someone” (E) is ambiguous.
(b) Ambiguity consists in the expression of
distinct contents.
(c) If (7) were true, (E) could only express one
content.
Hence, (7) is false.
((b) is supported by the idea that contents
cannot be ambiguous)
The idea is that if (7) were true, (E) would express
something like
(C)
P2(Greet, <everyone, someone>)
P2 is a function from relational contents and pairs of
nominal contents to propositional contents, and,
importantly, the order of the elements of the pair
indicates only agent-patient relationships.
So, P2(Greet, <John, Mary>) is the proposition that John
greets Mary, and so on.
But (C) would be ambiguous! For although it is
determined what agent-patient roles the quantifiers take,
their scopes are left undetermined!
Reply 1:
We can deny (c), i.e., the claim that if (7) were true,
(E) could only express one content. That is, we
could claim that nominal quantifiers are indexed or
marked, so that (E)’s ambiguity consists in its
expressing contents like (C), differently indexed, as
per:
(C’) P2(Greet, <everyone1, someone2>)
(C’’) P2(Greet, <everyone2, someone1>),
where the subscripts indicate scope.
Reply 2: We deny (b), and claim that ambiguous
sentences can express single contents. It follows
that contents can be ambiguous!
But what could it mean to say that a content is
ambiguous???
Whether on a truth-theoretic or conceptual role
theoretic framework, the idea of ambiguous
contents is, in one respect, straightforward:
On the former, the ambiguity of (C) consists in
its having different extensions (intensions, truthconditions, etc.) on different ”readings”.
On the latter, the ambiguity of (C) consists in its
figuring in different inferences depending on the
”reading”.
Since the different truth-conditions or inferential
patterns can be described unambiguously (using
first-order logic), at least part of what it is for
contents to be ambiguous can be described.
However, someone might very understandably
object that if sameness of content does not
entail sameness of inferential role or
coextensiveness, it is unintelligible what
”content” means.
Let us grant that this is true in one sense of
”content”: let’s stipulate that sameness of Acontents entails sameness of inferential role and
coextensiveness (etc.).
But I have been speaking of propositional contents
as thought contents, i.e., as the objects of
propositions attitudes, and I have described them
as a kind of structured entities, involving essentially
a number of non-composite contents/concepts. Let
us call contents in this sense ”B-contents”.
Reply 2 is thus the claim that the B-content of an
attitude does not determine determinate Acontents. Similarly, that a sentence expresses a
given B-content does not determine which
determinate A-contents the sentence has.
Were all these philosophers from William of
Occham to Jerry Fodor just wrong, then, in
holding that contents cannot possibly be
ambiguous?
No, for it seems plausible that sameness of noncomposite B-contents entails sameness of Acontents. It would be absurd to propose that,
e.g., there is a single yet ambiguous concept
bank. It is possible that exclusive focus on this
kind of example has sustained the idea that
contents cannot possibly be ambiguous.
I am proposing merely that (certain cases of)
structural ambiguity consists not in the
expression of distinct contents, but in the
expression of single, yet ambiguous, contents.
OK, but what are the ”readings”, relative to
which contents can have different A-contents?
Related question: what is it for a speaker to
”interpret” a content one way rather than
another?
One proposal is to say that readings of contents are
speakers’ dispositions to infer with them (cf. Carruthers).
Thus, one way to ”read” (C) is to be disposed to infer with
it the way one would infer with ”xy (x greets y)”.
Another way is to be disposed to infer with it as one
would with ”yx (x greets y)”.
E.g., on the former reading, the speaker would infer that
John greeted someone from (C), but not that someone
greeted John, and conversely for the latter.
Thus, it seems fully coherent to maintain that contents (in
our sense) can be ambiguous, and reject premise (b).
There is also a consideration indicating that contents
probably are ambiguous:
In silent reasoning, people are just as prone to commit
the fallacy of equivocation as when reasoning aloud. But
thinking involves operations on contents. So how can
they possibly be unambiguous?
Note, however, that people are not prone to equivocate
between the different senses of ”bank”. On the present
proposal, this is because they are operating on different
contents, and there is no risk of conflating them.
There is a response to this argument on behalf
of the defender of “Reply 1”, according to which
there are no ambiguous contents, but (7) is still
true, because nominal quantifiers are always
marked.
They might respond that when equivocating, we
are merely “forgetting” or “confusing” markings,
so that contents are always unambiguous after
all. The assessment of this response must
depend on what “markings” are supposed to be.
Could it be that a content’s being “marked” merely
consists in our being disposed to infer with it a
certain way? But if so, it does not seem to make
sense to say that we can “conflate” or “forget”
markings.
Suppose a speaker first infers with a content “as if”
it were marked one way, and then begins to infer
with it as if it were marked another. How, then, is it
marked? If we say that its markings changed, it
seems that we have said nothing other than that
the speakers started inferring with the content
differently.
Perhaps the proponent of marked contents should
say instead that having a certain marking is distinct
from our having certain inferential dispositions, but
that our inferential dispositions still depend on the
markings of contents. Markings might be some
categorical (perhaps physical) properties of
contents that merely help guide inferential practice.
But the fact that many speakers are prone to
equivocating rather ”consistently”, i.e., they have no
stable inferential dispositions, it still seems arbitrary
to say that the content such a speaker is inferring
with is marked one way rather than another.
In general, it seems that the fact that some
speakers equivocate so much shows that no
”markings”-solution is possible: on the one
hand, ”markings” must somehow connect to
inferential practice (otherwise, it would be
unable to explain the ambiguity of the relevant
sentences); on the other hand, people
equivocate to such an extent that to explain how
equivocation happens, the markings theorist is
forced to take the markings of contents to be
very disconnected from speakers’ inferential
practice.
It seems that the ”traditionalist” has the same problem. He
explains the ambiguity of ”Everyone greeted someone” as
consisting in its expressing either of:
(1) the proposition that xy (x greets y),
(2) the proposition that yx (x greets y).
But when people equivocate in silent thinking, e.g., inferring
from (1) what can only correctly be inferred from (2), how can
this be explained? Are they ”confusing” (1) and (2)? But what
grounds the claim that the speaker was first inferring with (1)
and confusing it with (2), rather than inferring with (2)? There
must be something about the speaker’s way of inferring with
the proposition that makes it (1) rather than (2), but in cases
of equivocation, both candidate propositions are equally well(or, rather, ill-) fitted with the way the speaker inferw with it.
So the pehnomenon seems to be better explained on the
hypothesis that contents/propositions can be ambiguous.
Recap:
There are at least two possible replies to the objection against
claim (7).
Both replies open up new, interesting possibilities. In
particular, it would be interesting to investigate which types of
linguistic ambiguity are more plausibly handled by recourse to
distinct contents (plausibly ”bank”) and which might be more
plausibly dealt with by appeal to ambiguous contents (some
or perhaps all cases of structural ambiguity).
Equivocation, we have seen, is likely to occur in the latter type
of case, but not in the former. Thus, equivocation in thinking
might be explained by ambiguity in contents. The alternative
explanation, which eschews ambiguous contents and opts for
markings that can be conflated, requires an account of how
markings are supposed to work.