Cognitivism is the view that the primary function of moral judgements is to express beliefs that purport to say how things are; expressivism is the contrasting view that their primary function is to express some desire-like state of mind. I shall consider what I call the freshman objection to expressivism. It is pretty uncontroversial that this objection rests on simple misunderstandings. There are nevertheless interesting metaethical lessons to learn from the fact that the freshman objection is prevalent among undergraduates and non-philosophers. It leaves for expressivists two awkward explanatory tasks. Number one is that of explaining why natural selection – which, by expressivism's own lights, favoured moral thought and talk because of their socially useful regulative and coordinating functions – did not favour a stance that would make moral thought and talk more effective in fulfilling these functions. Number two is that of explaining how moral thought and talk survive in cultural evolution, despite the prevalence of the freshman objection and related worries. I conclude that expressivism as a theory of actual moral discourse rather than a revisionist theory is either false or committed to an implausible error theory, according to which ordinary speakers are systematically mistaken about what they are up to when they make moral judgements.