Whatever the influence of G.E. Moore on twentieth century philosophy or
Keynes, it is worse than a mischaracterization of Moore to say, as does John
Medaille, that

"Moore's "Principia Ethica" (1903)  . . . promulgated the doctrine known as
"emotivism," that is, the idea that any ethical statement could only be the
expression of a personal preference."

"Emotivism" does not make even a hint of an appearance in  _Principia
Ethica_. Moore's argument was quite to the contrary. He believed that
goodness was an objective property.

David Andrews