To err is Griceian?

Speranza

Popper wrote:

"It is impossible to speak in such a way that you cannot be misunderstood."

I try to relate this to the writings of H. P. Grice -- and his symbolism, informal as it is -- in "Studies in the Way of Words". I try to evoke Strawson, too, who first saw 'understanding' in Griceian terms (in "Theoria").

I propose to use

□
◇
∃
∀

for -- respectively -- "it is necessary that...", "it is possible that", 
"there exists at least one...", and "every".

Also: "U" for utterer, "A" for "addressee", and suggested that 
'misunderstand' be understood as 'failing to grasp Utterer's intention".

One feels that Popper's dictum carries,  as my aunt Matilda would say, "one negative too many" -- or not -- and let us recall that, as double  negatives cancel each other out -- one may still use, as Grice does, "~" to refer to "not" (as in "_im_possible", used by Popper))

And of course, we may need to apply predicate logic, with

"x  understands y"

as a dyadic predicate -- abbreviated as "UND(x, y)", where 'x' and 
'y' will range over, respectively, addressee and utterer -- and where "UNDE" is correlative to "MEAN".

And so on.

Only then we may inquire as to the _reasons_ that Popper may have for saying what he says.

We may also recall Biblical Scriptures -- or for that matter, Witters's 'Slab!'

"The language is meant to serve for communication between a builder A and
an assistant B. A is building with building-stones: there are blocks,
pillars,  slabs and beams. B has to pass the stones, in the order in which A
needs them.  For this purpose they use a language consisting of the words
"block", "pillar"  "slab", "beam". A calls them out; — B brings the stone which
he has learnt to  bring at such-and-such a call. Conceive this as a complete
primitive language"  (Wittgenstein, Philosophical Investigations 2.)

-- and imagine scenarios when it is not possible to _misunderstand_ "Slab!" -- or for that matter, given, say, Papal Infallibility, the idea, that the Pope got, from somewhere, that there is only one body in heaven. Or not!

Cheers