Are there other situations where the Competence Assumption does not
apply? (Either other general situations like disjunction, or
more specific scenarios you can imagine?)
Does disjunction always lead to ignorance implicatures? Or can you
find situations where it doesn't?
The way I described this door example was slightly different from
the classic Monty Hall problem; recall that I described it from
the point-of-view of an outsider (a person watching it on TV).
In the classic Monty Hall problem, the game show host knows which
door has the prize, and the game show host tells the player
"There's a prize behind Door #1 or Door #2". Clearly the
Competence Assumption does apply here, because a
person playing the game knows that the host knows where the
prize is.
And yet, if the game show host says "There's a prize behind Door
#1 or Door #2", the contradiction we saw in the module still
does not arise, even though the Competence Assumption applies.
Have students discuss and try to figure out why not.
(The answer is that the maxim of quality would never yield the
weak implicatures (ii) and (iii) in this scenario. Remember that
the maxim of quality means we expect speakers to be as informative
as is appropriate for the scenario. In this scenario,
it's a game show, so we know the host won't tell the answer;
that would ruin the game. So we don't consider "There's
a prize behind Door #1" or "There's a prize behind
Door #2" to be possible alternatives; a game show host
in this scenario would never say those things. Since they're
not possible alternatives, those weak implicatures never arise,
and therefore the later contradictions related to them also
do not arise.)
Throughout this module we have been developing an argument that
the competence assumption doesn't necessarily apply in
"or" statements. It still can apply, though. Here
we will see some examples where the competence assumption
still works, by analyzing free choice implicatures,
which also come from statements with "or" but which
are very different than the sort of ignorance implicatures
we saw above.
First, some background concepts. "Or" is often thought
to trigger two kinds of implicatures: ignorance implicatures
and exhaustivity implicatires. Ignorance implicatures
are what we've seen in this module: "X or Y" is often
interpreted as meaning that the speaker does not know X and
the speaker does not know Y (i.e., at least one of them is
true but the speaker doesn't know which one). This is the
implicature that arises when the competence assumption doesn't
hold.
The exhaustivity implicature, on the other hand, is
when people interpret "X or Y" as meaning "X or Y
but not both". (Logicians call this interpretation "exclusive
or", or "XOR", in contrast with the logical definition
of "or" which means "X and/or Y".) This implicature
is a scalar implicature, just like the example we saw in previous
modules with "Josh is smart" (implicating that the
speaker doesn't think Josh is brilliant): it comes from thinking
about a stronger term. Specifically, if someone says "X or
Y", we might think "Why didn't he say 'X and Y'?
He must not believe it!"
Now with those preliminaries out of the way, let's get to the
issue at hand: free choice implicatures. To start, let's
look at an example.
During the Russian
invasion of Ukraine in 2022, people in many other countries
debated whether or not their militaries should intervene. On the
"pro" side, people argued that (1) it's a humanitarian crisis and
the people of Ukraine need and deserve the world's help in defending
their country; and (2) the world needs to send a message that wars
of aggression are not tolerated, and standing aside now would
constitute "appeasement" (see Geoffrey Nunberg's
article
on the origins and connotations of this term) that basically just
rewards Vladimir Putin for imperialist behaviour and encourages him
and others to keep doing it. On the "con" side, one argument (among
others) was that starting a world war with Russia would lead to a
much greater humanitarian disaster than the one that's already
happening; and in the most extreme case it could even lead to
nuclear war, i.e., the end of humanity.
Noam Chomsky lays out those options explicitly in
an
interview: "Like it or not, the choices are now reduced to an
ugly outcome that rewards rather than punishes Putin for the act of aggression
– or the strong possibility of terminal war."
The
bit in italics is an utterance with "
or", and it triggers
a free choice implicature, which we'll see below.
Here, Chomsky is not expressing that he doesn't know which option is
available. What he really means is that he knows (or at least
believes) both options are available, but we can only choose one
and not both. In other words, this utterance still has an
exclusivity implicature (we can have appeasement or
war, but not both), but it does not have an ignorance
implicature (it doesn't mean he doesn't know which we can have).
This is a classic free choice implicature. When we combine
disjunction (or) with a modal verb like "can",
we often get this sort of interpretation. For example, "You
can have cake or you can have ice cream" is often understood to mean
that both are available, but once you choose one you can't get
the other. To appreciate how this is different from the literal
meaning of or, let's look at a truth table of what
that utterance would literally (semantically) mean:
you can have cake |
you can have ice cream |
You can have cake or you can have ice cream |
T | T | T |
T | F | T |
F | T | T |
F | F | F |
In other words, if it's true that you can have cake and
it's also true that you can have ice cream, then the
utterance "You can have cake or you can have ice cream"
is true. But, semantically, this utterance is still
true even if you can't have ice cream. For example,
if there is no ice cream (maybe the ice cream is
all gone) but there is cake and you can have the
cake, then "You can have cake or you can have
ice cream" is still literally true,
because at least one of its parts (you can have
cake) is true. This is not how we usually interpret
it in reality; in reality we usually interpret it
as meaning that (1) you can have cake, (2) you can
have ice cream, but (3) you can't have both. Thus,
the way we interpret these sentences is not the
literal, semantic interpretation, but is instead
based on a free choice implicature. (See Geurts,
chapter 6, for a more detailed discussion of
free choice implicatures and how they work.)
Remember that, as we discussed above, the competence
assumption doesn't apply for ignorance implicatures
related to "or". But it does apply for
free-choice implicatures. If we think someone
is making a free-choice implicature, we believe
they have an opinion about each option. If
someone tells me "You can have cake or you
can have ice cream", and if I interpret
that as meaning that both are available and I
can choose either one of them (a free choice
implicature), then I believe the speaker
knows cake is available and knows ice cream
is available; I don't think he would have
said "You can have cake or you can have
ice cream" if he actually isn't sure
whether or not there is any cake. Likewise,
if Chomsky says "we can have an ugly outcome
that appeases Putin or we can have a civilization-ending
war", we don't think that he means he doesn't
know which of these is possible; we think he
knows (or at least believes) that both are
possible (he wouldn't have said that if he
had no opinion about whether or not a world-ending
nuclear war is possible).
Discuss and compare free choice implicatures,
exhaustivity implicatures, and ignorance
implicatures. Can students figure out an
explanation for how and why free choice
implicatures arise, based on the cooperative
principle and/or the competence assumption?
Can students think of examples where the
same disjunctive sentence might get different
interpretations (different implicatures) in
different contexts?