e/Open Question Argument

Information
has gloss	eng: The Open Question Argument is a philosophical argument put forward by the British philosopher G. E. Moore in . The type of question Moore refers to in this argument is an identity question, "Is it true that X is Y?" Such a question is an open question if a conceptually competent speaker can question this, otherwise the question is closed. For example, "I know he doesn't eat meat but is he a vegetarian?" would be a closed question. However, "Is the morning star the same thing as the evening star?" is an open question; the question cannot be deduced from the conceptual terms alone. The Open Question Argument claims that any attempt to identify morality with some set of observable, natural properties will always be an open question (unlike, say, a horse, which can be defined in terms of observable properties). Moore further argued that if this is true, then moral facts cannot be reduced to natural properties, and that therefore ethical naturalism is false.
lexicalization	eng: Open Question Argument
instance of	c/Philosophical arguments