Full Idea
Moore's Open Question argument led, however unintentionally, to the rise of anti-realism in meta-ethics (which leads to distinguishing values from facts).
Gist of Idea
The Open Question argument leads to anti-realism and the fact-value distinction
Source
comment on G.E. Moore (Principia Ethica [1903]) by Stephen Boulter - Why Medieval Philosophy Matters 4
Book Reference
Boulter,Stephen: 'Why Medieval Philosophy Matters' [Bloomsbury 2019], p.108
A Reaction
I presume that Moore proves that the Good is not natural, and after that no one knows what it is, so it seems to be arbitrary or non-existent (rather than the platonic fact that Moore had hoped for). I vote for naturalistic ethics.