INTERNALISM AND EXTERNALISM IN ETHICS
8. 1. I MUST start by distinguishing the use of these terms 'internalism' and 'externalism' in ethics from their use in the theory of meaning. So far as I can see, the two uses have not much to do with each other, and the use of these same terms in the two fields may be fortuitous. The dispute in the theory of meaning is, to speak roughly, between those who think that what someone means by what he (or she) says depends entirely on factors internal to him, and those who think that it is affected by external factors, i.e. by what the words mean in the language. This in turn depends on how other people use them. To take a well-known example, if someone says 'I have arthritis in my thigh', the externalist will say that he cannot mean 'in my thigh', because 'arthritis' means 'a pain in a joint', and the thigh is not a joint. But the internalist will say that he may be giving his own meaning to the words, dependent on what he is thinking.
On the face of it (though I am not an expert in the theory of meaning) this dispute does not look too difficult to resolve, if we distinguish between speaker's meaning and meaning in a language. The speaker's meaning may be what would be more correctly expressed by saying 'I have a pain in my thigh similar to what one has when one has arthritis in a joint', or possibly 'I have arthritis in one end of my thigh, namely in my hip'; the meaning in the language is such that what he says, taken literally, is a self-contradiction. But I shall not be concerned with this dispute.
In ethics, the dispute between internalists and externalists has been formulated in different ways, and some of the differences are very important. I shall myself use the terms in the following way. An internalist is someone who thinks that one cannot make a moral judgement sincerely (i.e. think something moral) without being motivated in some way towards actions in accordance with it (by oneself____________________