Expressivism is the view that certain kinds of language have the function of expressing states of mind rather than representing facts. So according to expressivists, when I say “Murder is wrong!” I don’t describe a state of affairs, but avow or display or advocate a negative attitude toward murder. More specifically, expressivism holds that words like ‘ought’ or ‘wrong’ conventionally function to express non-cognitive attitudes: attitudes other than straightforward belief, such as emotions or intentions. It holds that these non-cognitive attitudes explain those words’ meanings rather than just happening to be frequently correlated with their use. And it holds that the meaning and function of these words differ in a fundamental way from ordinary description. Different expressivists target different kinds of language, associate them with different attitudes, and locate the contrast with description in different ways, producing a diverse family of views.