 It is essential to understanding expressivism that expressing a thought is not the same thing as reporting a thought – when I say “The sun is shining”, I express my belief that the sun is shining, rather than reporting it, for which I’d have to say “I believe that the sun is shining.” Mark Schroeder (2010) has recently emphasized that the core expressivist claim is that the sentence “Murder is wrong” is related to disapproval of murder in just the same way as the sentence “The sun is shining” is related to the belief that the sun is shining, whatever that is. The only difference is that the expressed state is non-descriptive. This has significant semantic consequences, to be sure. Famously, since non-descriptive states lack truth-conditions, (pure) expressivists cannot explain the inferential relations among them in the usual way, but rather in terms of agreement or disagreement in attitudes (Stevenson 1937, Gibbard 2003). Attempts to do so have proven controversial, to say the least. For discussion, see the entry on  Moral Cognitivism vs. Non-Cognitivism.