C. K. Grant and H. P. Grice

There was a long polemic, Oxonian & otherwise, regarding this word,
"implication". P. H. Nowell-Smith, of Trinity, Oxford, (writing in 1955 --
_Ethics_, Penguin) was calling this "contextual" implication.

Then there's C K Grant, writing for _Philosophy_, calling this _pragmatic_ implication.

Other essays are C Hungerland, writing for _Inquiry_, calling this
"Contextual implication", too. Strawson calling this "presupposition" (in
'On referring', etc). Etc. Of course, it was up to Grice to start talk of
_implicature_ (in 1967).

In 1961 ('The Causal Theory of Perception'), Grice
was still using "implication". The idea of _implicature_ as "term of art"
as Grice puts it, came thus between 1961 and 1967. For Grice there are
indeed various types of _implicature_ and we should (perhaps) be careful
there. Unless otherwise stated, I (and Levinson) use _implicature_ to mean
_conversational_ implicature, but the original Grice taxonomy seems to have
been:

implicature
.
.
. .
. .
conventional nonconventional
I .
.
. .
. .
nonconversational conversational
II .
.
. .
. .
particularised generaliseed
III IV


Examples by Grice as they fit Grant's pardigm:

I. "He is an Englishman, therefore brave"
+> his bravery follows from his Englishry.
(Grice, _Studies_, p.25)


II. "Bad luck!" +> I regret your bad luck
rather than I wish you bad luck.
Due to nonconversational maxim, "Be polite"
(Grice, _Studies_, p.28)


III. "He hasn't been to prison yet"
(first example by Grice 1967)
+> he's potentially treacherous.
(Studies, p.24).


IV. Some people are non-Gricean
+> some are Gricean.
(implicature attached to "some").
(Grice, _Studies_, p.22).


It is to the IV-type that the "Austin-type" fishy implicatures of
"voluntarily" seem to apply since they, precisely, attach to a range of
particular adverbs (notably "voluntarily").