The systematic philosophical investigation of the language and logical relations within Normative Ethical systems.

Those who investigate 'Metaethics' divide into two generally recognized groups:

Cognitivists argue that moral language is semantically rich (i.e., meaningful), although there is disagreement as to what meaning moral designators convey. Natrualists are cognitivists who argue that moral designators point to some natural property of the world (e.g., pleasure or pain). The consequence of this view is that moral propositions can be translated into empirical propositions (e.g., "Lying is wrong," translates into something like, "Lying causes pain.").

Nonnaturalists like G.E. Moore, on the other hand, maintain that normative language signifies some set of basic non-natural properties (e.g., Goodness, Rightness, etc.) which cannot be reduced to any simpler notions. In order to understand moral language, therefore, we must exercise our moral intuition, or rely on some special source of enlightenment perhaps even divine revelation.

Unlike the Cognitivists, Non-Cognitivists are committed to the view that moral language is literally meaningless. That is, moral designators convey no cognitive content at all; they neither refer to natural or non-natural properties in the world. Non-Cognitivists tend to fall into one of two camps:

Emotivists, Like A.J. Ayer, hold that moral language is an example of performative language, and functions like a kind of verbal punctuation. On this view, the purpose of a moral proposition is to express one's emotional response to some action or behavior and/or attempt to cause a similar reaction in others. Prescriptivists like R.M. Hare, hold the view that moral language is really just a from of imperative. Moral assertions, on this view, are reducible to the claim "Don't do that!"