Claim that a sharp distinction can be drawn between factual statements and value judgments, only the former being regarded as stating anything and as being true or false; the latter having meaning by doing something other than stating (for example, expressing attitudes: see speech act theories).
The claim underlies emotivist and prescriptivist - as against descriptivist - views in ethics; and is related to (though not identical with) George Edward Moore's attack (in his Principia Ethica (1903), §§5-14) on the 'naturalistic fallacy' (also see: naturalism).
However, the sharpness of the distinction has proved to be hard to maintain.
Also see: Hume's law
C Beck, 'Utterances which Incorporate a Value Statement', American Philosophical Quarterly (1967)