Non-cognitivism (with or without the hyphen) in ethics is the view that ethical statements do not describe features of actions or agents, but rather express attitudes of the speaker regarding those actions or agents. Quoting the philosopher Simon Blackburn: “Hence, it is supposed, there is nothing ethical to know, for knowledge aims to track or represent independent truths about things” (The Oxford Dictionary of Philosophy). Mark Schroeder describes non-cognitivism, less clearly, as a non-descriptivist view that seeks “to explain the meaning of words by other means than by saying what they are about”.
Schroeder analyzes a number of 20th century non-cognitivist theories, including emotivism, prescriptivism and expressivism. He finds all of them lacking in various ways, especially in their failure to adequately explain how we actually use ethical language and reason about ethical subjects. But he also believes that non-cognitivist theories correctly draw attention to the fact that there is more to meaning than truth-conditions.
It seems to me that non-cognitivist theories are basically correct, but in a limited sense. We cannot analyze ethical statements in terms of attitudes, as some non-cognitivists (used to) do. For example, “Stealing is wrong” does not literally mean anything like “I disapprove of stealing and everyone else should too”. “Stealing is wrong” means that stealing conflicts with the moral rules. But what such a statement means in another sense, i.e. what we can conclude when someone says that stealing is wrong, is that the speaker has a certain negative attitude toward stealing and thinks that other people should have the same attitude. This is what it “means” or shows when someone says that stealing is wrong, although “stealing is wrong” has a different literal meaning.
It’s obvious that ethical statements aren’t descriptions; they’re evaluations. They say how the world should be, not how it is, even though many of them are grammatically similar to descriptions and have literal meanings that imply that they are descriptive of some state of affairs, i.e. that some action is in harmony or conflict with certain moral rules or that some agent tends to obey or disobey those rules. Stating that an action is in conflict with a rule sounds like a description and has the force of a description — that is such a statement’s literal meaning. But making such a statement is evidence for a different state of affairs; it means that the speaker is opposed to the action in question and thinks other people should oppose it too. (10/23/11)