McEvoy was referring to J. L. Mackie, the Oxford philosopher -- and by
referring to Mackie, McEvoy, by implicature, was referring to a possible
Griceian criticism to the Library-of-Living-Philosophers volume on Popper.
Oddly, we say that Mackie and Grice are "Oxford philosophers". And they were.
In fact, as Geary puts it, Grice is "an Oxford philosopher if ever there is
one."
When Grice arrived in Oxford, he was called (by his pretentious classmates) a
'Midlands scholarship boy' -- as he was! A few years later, J. L. Mackie was
making it into Oriel (Grice's "alma mater," besides Clifton proper, was Corpus).
Mackie spends quite a bit analysing Grice's account of 'if' in his "Paradox"
essay. It is a detailed analysis of one of Grice's detailed William James
Lectures -- which Grice later entitled, "Indicative Conditionals". This Grice
did because he wanted to make the point that perhaps Mackie is right and
"Subjunctive" Conditionals need a different treatment. They don't of course!
As a vengeance, Grice dedicated the first Carus lecture to Mackie's "Inventing
right and wrong".
It takes an Oxford philosopher to criticise another one!
In his "Valediction," Grice compares the "Oxonian Dialectic" to the "Athenian
dialectic", of, yes, Socrates, Plato, and Aristotle -- not necessarily in that
order!
Cheers,
Speranza
