Grice's gloss for the first "Marmaduke Bloggs" conversation

Grice wants to say that B is being conversationally impeccable, in parts.

-- Yet, he is accepting the counterintuitive inference patterns I and II.

I: a does not exist
__________
Therefore, a is not F


II. a is not F
______________
Therefore, something is not F

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Or, at least, as Grice more guardedly has it, he is 'seemingly accepting' then in his remarks,

"Marmaduke Bloggs doesn't exist; he was invented by the journalists", "Didn't you hear me say that Marmaduke Bloggs does not exist?"

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