Grice on the Implicatures of Forbidding

B. Aune has brought my (and listers´s of analytic-philosophy-history mailing list) attention to a recent essay in a Science magazine, on

´forbidden´

sic in scare quotes on colours. The main point being a sort of ´challenge´ to Grice´s informants (as reported by Chapman, _Grice_), i.e 9-year-olds, to the effect that possibly,

Nothing can be red and green all over

(see my "Red and green all over again").

And I wondered a few things in phil-anal-hist. But I would like to focus here on Grice 2001. In considering the "aequi-" vocality of "can´t" he considers the corresponding square of oppositon for ´practical´ modalities. Old bag of the deontologists: may, may not, must, must not.

But I do wonder:

It seems to me that to ALLOW someone to have 2 + 2 = 5

makes MORE Sense (or is this my native tolerance?) than to

FORBID him, or her, as the case may be (it, more rare).

The point. Philosophers are tolerant, because they know that "can´t" best applies to logical impossibilities.

2 + 2 = 4

is actually NOT one. It´s a truism, syntactic in nature, and algebraically challeangeable. In fact, most defenders of the analytic-apriori accept this much, since perhaps Witters made it known that tautologies do not speak about the world.

So, it´s otiose to forbid someone to have five apples if he has four. Because it´s not something he WILL do, regardless. He may still be allowed to do it, since there´s no harm (in allowing -- he may report back a ´change of subject-matter´).

So when the Science entry goes,

"colours which were once ´forbidden´ by Kant
-- no longer"

The claim concerns the shady area of the

SYNTHETIC a priori.

In a rough note to his Valedictory Essay, Grice indeed meant to add a few notes about "Nothing can be red and green all over" as a "candidate of the synthetic a priori", his wording, but thought better. The notes are in BANC 90-135c anyway.

Etc.