The "error" theory is a special case in the old debate between "cognitive" and 'non-cognitive" meta-ethical views. Cognitivism holds that there are moral properties or moral facts, and that the aim of normative ethical discourse is to describe them, and preferably to be right about them, in something like the same way that there are bodies and events we call "astronomical," (stars, planets, collisions, the collapse of a star into a black hole) and the aim of discussing "astronomy" is to describe them, and preferably to be right about them. For example, the wrongness of murder may be a fact in the world. If it is then the goal of the sentence "murder is wrong" is to name that fact. Non-cognitivists claim that there aren't any moral properties or facts, so they can't be described, rightly or wrongly. But it also generally adds that this doesn't mean normative ethical statements are wrong. It just means that su...
