In his paper, “The Content-Force Distinction”, Peter Hanks claims
that three prominent semantic accounts of interrogatives—those of Hamblin
(1973), Karttunen (1997), and Groenendijk and Stokhof (1982, 1997)—are all
inadequate because they fail to preserve the univocality of “knows that” (e.g.
Jones knows that Smith is tall) and “knows
whether” (e.g., Jones knows whether
Smith is tall). I will not examine the three accounts of interrogatives that
Hanks impugns here. Nor will I attempt
to assess the various replies to Hanks’ argument that may be offered on behalf
of the three approaches in order to show that they can, in fact, preserve the
univocality of “knows” across cases of “knows that” and “knows whether”.
Instead, I will examine Hanks’ argument directly, and challenge the assumption
that the term “knows” is univocal in the way Hanks suggests.
Hanks begins by noting that the term “knows” is genuinely ambiguous
when used in its acquaintance sense (e.g., “Jones knows Wilson”) and in its
propositional sense (e.g., “Jones knows that Smith is tall”). This is what
explains the infelicity of the following sentence:
(1) Jones knows that Smith is tall and Wilson.
In short, it is ambiguity of “knows” in its acquaintance and
propositional senses that explains the infelicity of (1). Hanks draws the preliminary conclusion that
one cannot form a conjunction with a genuinely ambiguous use of “knows” (in the
manner illustrated in (1)) without infelicity. So goes the first stage of Hanks
argument.
The second stage of Hanks’ argument consists in his contention that
the difference between “knows that” and “knows whether” is best conceived of as
the difference between a knowledge claim that modifies indicative content and a
knowledge claim that modifies interrogative content, respectively. In support
of this conclusion, Hanks invites us to consider two statements:
(2) Jones knows that Smith is tall.(3) Jones knows whether Smith is tall.
It is clear that (2) and (3) have different contents. Suppose that Jones knows that Smith is not
tall. In that case, (2) would be false, while (3) would be true. But how are we to make sense of the
difference between (2) and (3). It is
tempting to view (3) as a disjunction of two knowledge claims, along the lines
of (4):
(4) Either Jones knows that Smith is tall or he knows that Smith is not tall.
On the present suggestion, “knows whether” is elliptical for a
disjunction of a pair of competing “knows that” claims.
However, Hanks maintains that the above analysis of “knows whether”
is unsatisfactory. This is because the commitment
to compositionality requires that we see expressions like “whether Smith is
tall” as making the same semantic contribution to different sentences in which
it occurs. But this requirement cannot be satisfied if we conceive of (3) along
the lines of (4). For example, consider
(5):
(5) Jones asked whether Smith is tall.
If we assume that “knows whether” statements are an elliptical
treatment of a disjunction, then (given the commitment to compositionality) we
would have to interpret (5) along the lines of (6):
(6) Either Jones asks that Smith is tall or Jones asks that Smith is not tall.
But (6) is clearly infelicitous.
Hence, interpreting “knows whether” as a disjunction comes at the cost
of compositionality.
According to Hanks, our best chance of making sense of (3) in a way
that satisfies the compositionality requirement is to hold that the embedded
expression “whether smith is tall” is an instance of interrogative content. How we understand interrogative content will
of course depend on our theory of interrogatives, which is what is under
dispute in Hanks’ paper. But the basic idea is this: the expression “Jones knows
whether Smith is tall” is best interpreted along the lines of “Jones knows the answer
to: is Smith tall?” This is the
conclusion of the second stage of Hanks argument.
In the third, and final, stage of his argument, Hanks observes that
the following claim is felicitous:
(7) Jones knows that Smith is tall and whether Wilson is married.
According to Hanks, this suggests that “knows” is not ambiguous across
“knows that” and “knows whether”.
Given that “know that” is a knowledge claim with embedded indicative
content, and “know whether” is a knowledge claim with embedded interrogative
content, it follows that “knows” is not ambiguous across indicative and
interrogative content. Hence, Hanks concludes that those accounts of
interrogative content that fail to preserve the univocality of “knows” across
indicative and interrogative contents are mistaken.
Here is a recap of all three stages of Hanks’ argument and his
conclusion:
Stage 1: One cannot form a conjunction with a genuinely ambiguous use of “knows” without infelicity.
Stage 2: “knows that” and “knows whether” correspond with knowledge claims with embedded indicative content and interrogative content, respectively.
Stage 3: One can form a conjunction with “knows that” and “knows whether” without infelicity.
Conclusion: Knowledge claims with embedded indicative content and embedded interrogative content do not involve a genuinely ambiguous use of “knows”.
I believe that the first stage of Hanks argument is unsound. Consider the following sentence:
(8) Jones knows how to play the piano and that the concert is being held downtown.
(8) is no less felicitous than (7).
However, (8) features an ambiguous use of “knows”. The first conjunct is
an instance of “know how” while the second conjunct is an instance of “know that”. Or, for another example, consider (9):
(9) Jones knows how to play the piano and whether the concert is being held downtown.
(9) is also perfectly felicitous. But it too involves an ambiguous use
of “knows”. The first conjunct is an
instance of “know how” and the second conjunct is an instance of “know whether”.
(8) and (9) illustrate that is possible to have a conjunction that
features the ambiguous use of “knows” without infelicity. Hence, we cannot
conclude from the fact that (7) is felicitous that it involves a univocal sense
of “knows”. The upshot is that it is
unclear that three prominent theories of interrogative content Hanks mentions have
the burden of preserving the univocality of “knows” across “knows that” and
“knows how” since the claim that there is such univocality remains
unestablished.
