The emotive theory of ethics stems from the work of the logical positivists who reject naturalism and absolutism as it is an impossible position to hold- there and no facts that an ethical statement can assert. Thus logical positivists hold moral statements meaningless unless they are analytic or synthetic statements. Analytic statements are correct by definition and synthetic statements can be verified by reference to experience. The verification principle, used by logical positivists, shows that as goodness cannot be verified, ethical language is deemed to be meaningless. As morality is necessary but it is not verifiable, this creates an apparent contradiction.
Emotivism; when referred to as the Boo-Hurrah theory, it is due to the argument that morals are determined by people’s feelings and opinions, Ayer describes ethical language as a means to express emotion. When saying ‘murder is wrong’ to Ayer we are really saying ‘I don’t like murder.’ Since ‘murder is wrong’ is not analytic or synthetic it cannot be verified, thus rejecting the idea that ethical statements have objective meaning. Ethical claims are not designed to make factual statements but to invoke certain emotional responses in the hearer. The statement ‘you know that when you stole from that person you did wrong’ is capable of verification as it can be assessed from the experience of that individual. This difference helps to give authority to ethical statements which convey certain attitudes but do not tell someone how to live a moral life. For the emotivist, all we can do is recognise the power to persuade that lies behind moral statements, but we should not be deceived into thinking they have moral value. People make decisions based on emotions, therefore the emotivist approach describes how the world operates accurately. Thus emotivism effectively resolves the argument as to why moral disputes can never be resolved.
C.L Stevenson agrees with Ayer in the sense that ethical statements express emotion, but proposes that two people may have the same idea of what is ‘good’ and ‘bad’ but both respond differently to this gut feeling. Stevenson’s view goes beyond Ayers ideas of matching opinion, he shows that ethical statements have an element of persuasion. ‘Stealing is wrong’ is not only said to express ones opinion, but also to vocalise to others that they should feel it is wrong too. Brandt attacks Stevenson's view, stating that he assumes there is a ‘magnetic influence.’ This means that when we express ethical language, we don't expect people to agree - it is foolish to presume that our language has a magnetic influence on others. And whose emotions should we follow? Those around us? Leaders? Stevenson’s concept ultimately belittles our ability to reason. R.M. Hare says that morality must involve the use of reason as he cannot accept that such terrible acts (e.g. the Holocaust) can be reduced to to ‘I believe that killing is wrong.’ Thus Vardy describes emotivism as ‘hot air and nothing else.’
James Rachels criticised emotivism in his book ‘The Elements of Moral Philosophy’ arguing that Ayer and Stevenson are wrong to remove reason from moral judgements. He criticises Ayer for drawing a parallel between the ‘ouch’ reaction to stubbing your toe and the ‘that’s wrong’ reaction to reading about a murder in a paper. As Mel Thompson famously said; ‘you cannot reduce morality to a set of cheers and boos.’ It stops us from seeing the importance of human qualities and causes us to treat others as ‘always means, never ends.’- Alasdair MacIntyre. Thus emotivism is often rejected as a valid explanation for the relevance of the use of ethical language.