  Non-cognitivism is not a form of reductive naturalism about the contents of moral judgments, beliefs and sentences. It does not equate the property seemingly predicated in such judgments with any natural property, precisely because it denies that the (primary) function of such expressions is to predicate properties.  But in another good sense non-cognitivists are naturalists. They offer a reduction of the attitude of accepting a moral judgment to a perfectly naturalistic sort of attitude such as the attitude of approval or disapproval. And they do not postulate any properties which cannot be reduced to natural properties. Thus another motivation for accepting non-cognitivism has been naturalism. If someone doubts the prospects for reducing moral properties to natural properties (perhaps under the influence of the open question argument), they need not concede that there are any extra-natural or supernatural properties.  One can simply reinterpret even the moral judgments one accepts as predicating no properties at all. Or, as with the more sophisticated versions of non-cognitivism, one can allow them to predicate natural properties and argue that the appearance that they do something other than this is due to the additional expressive component in their meaning. One’s naturalism will then not commit one to giving up moral judgments or reducing moral properties to natural properties (Ayer 1952, 106–7).