The difference between performatives and constatives was articulated by John Austin fifty-odd years ago, and has kept us busy in all cultural domains, usually extending the reach of the former at the expense of the latter. As you’ll remember, there’s not always an explicit marker of performativeness. Some performatives look exactly like constatives, and it’s only the context that makes the difference. For example: “He is not guilty” (said by a newspaper reader in reference to some ongoing trial), versus “Not guilty” (said in the course of entering a plea). When entering a plea in court, “Not guilty” does not mean “It is a fact that I am not guilty of the matter I am charged with”: if it did, pleas could become subject to charges of perjury, and defendants who were later found guilty would undergo extra punishment for having attempted to assert their rights in court; which is repugnant to the idea of a fair trial. Rather, it means, “I hereby challenge you to lay out the most convincing proof you can to the effect that I am guilty.” It’s one of those speech acts that can only be answered by another speech act, one that says, “I accept your challenge and here’s my brief.” An old but good article by Carl Selinger, “Criminal Lawyers’ Truth: A Dialogue on Putting the Prosecution to Its Proof on Behalf of Admittedly Guilty Clients,” clarifies the distinction.