GRICE AGAINST THE MANOEUVRE

 Grice explains it best in the Prolegomena.

It wasnt like he just FELT he had to criticise the manoeuvre. The manoeuvre was in his way!

Aiming at defending a causal theory of perception, in the traditionalist vein of a Price, Grice finds that

It looks to me as the pillar box in front of me is red

-- i. e. a mere report of sense datum

would be accountable as something ridiculous to say. Grice is thinking G. A. Paul, a Scot who was an avid member of the Saturday mornings until he week he died after sailing in the North Sea.

This is how Grice puts it:

Another example which occurred to Grice in “Causal Theory of Perception," Aristotle Society Supplementary Volume, "as to others before him," he adds as the good traditionalist he is, is that the old idea that perceiving a thing involves having (sensing) a sense-datum (or sense-data) might be made viable:  

-- by rejecting the supposition that a sense-datum statement reports the properties of entities of a special class, whose existence needs to be demonstrated by some form of the Argument from Illusion, or the identification of which requires a special set of instructions to be provided by a philosopher; 

and 

-- by supposing, instead, that "sense-datum statement" is a class-name for statements of some such form as "* looks (feels, etc.) $ to A" or "it looks (feels, etc.) to A as if."s 

Grice hopes by this means to rehabilitate a form of the view as reviewed in a whole chapter by Price in his volume, that the notion of perceiving a thing is to be analyzed in causal terms. 

But Grice had to try to meet an objection, which Grice finds to be frequently raised "by those sympathetic to Wittgenstein," -- an Oxford outsider, who had never heard of Price -- to the effect that, for many cases of perceiving, the required sense-datum statement is not available;

"Those sympathetic to Wittgenstein" would argue that, for when, for example, I see a pillar box in ordinary day-light, to utter: 

"That pillar box seems red to me.

-- far from being, as Grice's -- and indeed Price's -- theory requires, the expression of a boring truth, would rather be an incorrect use of words!

According to such an objection by "those sympathetic of Wittgenstein", a feature of the meaning, signification, or significance of  of the syntactical pattern:

"x looks é to A"

 is that such a form of words is correctly used only if:

either

DENIAL:

it is false that x is phi, 

or 

DOUBT

there is some doubt (or it has been thought or it might be thought that there is some doubt) whether x is phi.

Ridiculous!

All that we need to explain the perfectness of

"That pillar box has a taint of red to it."

is that there is a desideratum of conversational candour, and we are abiding by it!