Lying by Promising

This paper is divided into two parts. In the first part, I extend the traditional definition of lying to illocutionary acts executed by means of explicit performatives, focusing on promising. This is achieved in two steps. First, I discuss how the utterance of a sentence containing an explicit performative such as “I promise that Φ ” can count as an assertion of its content Φ . Second, I develop a general account of insincerity meant to explain under which conditions a given illocutionary act can be insincere, and show how this applies to promises. I conclude that a promise to Φ is insincere (and consequently a lie) only if the speaker intends not to Φ , or believes that he will not Φ , or both. In the second part, I test the proposed definition of lying by promising against the intuitions of ordinary language speakers. The results show that, unlike alternative accounts, the proposed definition makes the correct predictions in the cases tested. Furthermore, these results challenge the following necessary conditions for telling a lie with content p: that you have to assert p directly; that you have to believe that p be false; that p must be false; that you must aim to deceive the addressee into believing that p.