Ramsey and Grice

Bealer notes in his pdf

"’In “Theories” (in The Foundations of Mathematics, ed. R. B. Braithwaite
(London: Routledge and Kegan Paul, 1931), 212-36), F. P. Ramsey gave a
technique, not for defining “theoretical” terms, but rather for eliminating
them by means of existentially quantified predicate variables. To my knowledge, the idea of using existentially quantified predicate variables to construct
the kind of definition described in the text is first found in R. M.
Martin’s “On Theoretical Constants and Ramsey Constants,” Philosophy of
Science 31 (1966): 1-13. The idea was subsequently taken up by Lewis, Grice,
Harman, Loar, Shoemaker, Block, Cummins, Jackson, and many others."