Expressivism

Expressivism is a theory about the use of moral language in the field of Meta-ethics. Some of the early examples have a vintage from the Logical Positivist period after the publication of Wittgenstein's Tractatus. The most prominent example of this is Ayer's emotivism propounded in his Language, Truth & Logic. Later came the 'Projectivism' or 'Quasi-realism' of Simon Blackburn, the 'Prescriptivism' of Hare and the 'Norm-expressivism' of Allan Gibbard.

Such theories and other forms of non-cognitivism share a fundamental thesis about what is actually happening when we use moral language. When we make moral judgments, expressivists maintain, we are not referencing a moral fact but simply saying something that is reflective of an attitude we hold. This is in opposition to moral realism. Recently, expressivism has rejected its traditional line that moral sentences are not 'truth-apt' in the way a sentence about the location of a set of keys is.

Expressivists believe that when using moral langauage we are not claiming that a certain position is correct, but instead that we approve of it. So if someone said "killing is wrong" they are saying "I approve of the statement 'killing is wrong'" rather than "the statement 'killing is wrong' is true". Theories such as Blackburn's have gone on to develop complex logical apparatus along the lines of truth tables for an expressivist logic of morality (although Blackburn's quasi-realism has been criticized among others by Crispin Wright).

Counter-Arguments
The Frege-Geach problem &mdash; named for Peter Geach, who developed it from the writings of Gottlob Frege &mdash; claims that by subscribing to Expressivism one necessarily accepts that the meaning of "It is wrong to tell lies" is different from the meaning of the "it is wrong to tell lies" part of the conditional "If it is wrong to tell lies, then it is wrong to get your little brother to lie", and that therefore Expressivism is an inadequate explanation for moral language.

Frege-Geach contends that "It is wrong to get your little brother to tell lies" can be deduced from the two premises by modus ponens as follows:


 * If it is wrong to tell lies, then it is wrong to get your little brother to lie.
 * It is wrong to tell lies.
 * Therefore, It is wrong to get your little brother to tell lies.

In the second statement the expressivist account appears to fail, in that the speaker asserting the hypothetical premise is expressing no moral position towards lying, condemnatory or otherwise. The expressivist thus cannot account for the meaning of moral language in this kind of unasserted context.