Grice The Megarian -- from notes by Stanley and Loewer

Grice's Defense of the Material Conditional Account of Indicative Conditionals


The Indirectness Condition (see Strawson):

“that p would, in the circumstances, be a good reason for q”

“that q is inferable from p”

“that there are non-truth-functional grounds for accepting the material conditional”


Thesis to be examined:

“in standard cases to say ‘if p then q’ is to be conventionally
committed to (to assert or imply in virtue of the meaning of “if”) both the proposition p

q and the Indirectness Condition.

In contrast, Grice will argue that to say “if p then q” is just to say that p q, and the indirectness condition is a generalized conversational implicature.
Argument that the Indirectness Conditional is a conversational implicature, rather than what is said:

It has the features of a conversational implicature; it is nondetachable and cancelable.

(1) Either Smith is not in London, or he is attending the meeting.

(2) It is not the case that Smith is both in London and not attending the
meeting.

To say “If Smith is in the library, he is working” would normally carry the
implication of the Indirectness Condition; but I might say (opting out) “I know
just where Smith is and what he is doing, but all I will tell you is that if he is in
the library he is working.”

Cases in which the Indirectness condition is absent:

(1) Perhaps if he comes, he will be in a good mood.

(2) See that, if he comes, he gets his money.

(also biscuit conditionals are an obvious counterexample to the Indirectness Condition)

How, with the use of the maxims, can we calculate the generalized implicature of the
Indirectness Condition?

There is a general presumption that in the case of ‘p q’ a more informative
statement would be of interest. No one would be interested in knowing that a
particular relation (truth-functional or otherwise) holds between two propositions
without being interested in the truth-value of at least of the propositions
concerned…An infringement of the first maxim of Quantity, given the
assumption that the principle of conversational helpfulness is being observed, is
most naturally explained by the supposition of a clash with the same maxim of
Quality (“Have adequate evidence for what you say”), so it is natural to assume
that the speaker regards himself as having evidence only for the less informative
statement (that p q) – that is, non truth-functional evidence. (pp. 61-62)
So the basic idea is very simple. The material conditional assertion is very weak, and will almost always violate the Maxim of Quantity – it will almost always give one’s interlocutor less information than she desires. So it is clear to one’s interlocutor that one is not complying with the Maxim of Quantity, and the simplest explanation of why one is not complying with the Maxim of Quantity is that one only has evidence for the very weak claim that p q. Having evidence for this weak claim is having evidence that there is a connection between the truth of the antecedent and the truth of the consequent. So that is Grice’s idea.

How does Grice deal with the Paradoxes of Material Implication?

(1) If God exists, then everything is permissible.

According to Grice, (1) is true but unassertible. Our intuition that it is false is due, not to its falsity, but to its lack of assertibility. Suppose I am an atheist. Then I should just assert the negation of the antecedent (by the Maxim of Quantity).

(2) The butler did it. So if the butler didn’t do it, the gardener did.

After asserting that the butler did it, the conditional is unassertible, since the negation of the antecedent is known. Our sense that the inference is invalid is due to our sense that the conditional that is the conclusion of the argument is not assertible.

(3) I have three children.

This is true if I have four children (according to Grice), but it seems false to us. In the case of constructions that generate generalized conversational implicatures,
unassertibility and falsity can be confused.

Problems for Grice’s Theory:

Problem #1: Contraposition

Bennett’s example:

(1) Even if the Bible was divinely inspired, it is still not literally true.

(2) If the Bible is literally true, then it is not divinely inspired.

Certainly, (1) and (2) have intuitively different truth-conditions. But Grice’s strategy is hopeless to explain the difference in assertibility.
Curiously, all counterexamples to contraposition seem to involve conditionals containing “even” and “still”. As Stalnaker writes (Inquiry, p. 124):
One might reject the counterexample on the grounds that the conditional
contraposed is an “even if” conditional – a semifactual which should receive an
analysis different from the one given to ordinary counterfactual conditionals. But
it seems reasonable to assume, at least to begin with, that “even if” conditionals
should be explained in terms of the interaction of “even” with the ordinary “if”. If
we look to nonconditional uses of “even” it seems plausible to conclude that this
word has a purely pragmatic function…”Even Abe Lincoln lied to the American
people” seems to assert exactly what is asserted by “Abe Lincoln lied to the
American people”…
Still, one might worry that “even” has some semantic function here that obscures our
intuitions, and not a straightforward indicative conditional. It is most curious that all
examples of the failure of contraposition I know of in the literature either involve “even
if” conditionals, or relatively dodgy examples.

Other examples (p. 48 of Frank Jackson, Conditionals):

(3) If it rains, it will not rain heavily.

(4) If he works he will still not pass.

But I hear (3) and (4) as ‘even if’ conditionals (especially (4)).
Problem #2: Disanalogies in assertibility between “if…then” and “or” (Grice, p. 63)
According to Grice’s account, “If P, then Q” has the same truth conditions as “~P or Q”.

So similar puzzles about assertibility should plague us with disjunctions. As Jackson
elegantly puts the point (Frank Jackson, Conditionals, p. 21):
My final objection is that if the standard way of trying to explain away the
paradoxes is right, ‘or’ and ‘if..then’ are on a par in the relevant respect. It would, for instance, be just as wrong, and just as right, to assert ‘A or B’ merely on the
basis of knowing A as to assert ‘If A, then B’ merely on the basis of knowing
‘not-A’. And, more generally, ‘A; therefore, A or B’ should strike us as just as
much of a problem for the thesis that ‘A or B’ is equivalent to (A v B) as do the
paradoxes of material implication for the equivalence thesis. It is a plain fact that
they do not….the thesis that ‘A or B’ is equivalent to (A v B) is relatively
uncontroversial, the thesis that ‘If A, then B’ is equivalent to ‘A B’ is highly
controversial.

Of course, as you saw in your reading, Grice was well aware of this, and attempts to find
a solution by appeal to the different discourse functions of “or” and “if…then”. The
problem with this is that these different discourse functions don’t seem to come from the
semantic content of sentences containing “if…then” together with conversational norms
(since the semantic content of such sentences is the same as the semantic content of
certain “or” sentences). The worry here is that the different discourse functions end up
being due to semantic features of the words that are independent of contributions to what
is said, i.e. conventional implicatures. If so, then Grice’s theory ends up being a version
of Jackson’s theory."

Only that Grice predated Jackson for _decades_!