Ethical cognitivists hold that ethical sentences "do" express propositions: that it can be true or false, for example, that Mary is a good person, or that stealing and lying are always wrong. Cognitivists believe that these sentences do not just express feelings, as though we were saying, "Hey!" or "Yay for Mary!"; they actually express propositions that can be true or false. Derivatively, a cognitivist or a realist would say that ethical sentences themselves are either true or false. Conversely, if one believes that sentences like "Mary is a good person" cannot be either true or false, then one is a non-cognitivist.