Abstract There are many philosophical questions surrounding the notion of lying. Is it ever morally acceptable to lie? Can we acquire knowledge from people who might be lying to us? In order to answer these questions, however, we must first answer the question of what, exactly, constitutes the concept of lying. This paper examines three predominate definitions, as well as some cases-bald-faced lies and lies told with warrant-defeating provisions tacked on-that, arguably, pose problems for some of these definitions. Importantly, theorists working on this topic fundamentally disagree about whether these cases are genuine instances of lying and, thus, serve as counter-examples to the definitions on offer. To settle these disputes, we elicited judgments about the proposed counter-examples from ordinary language users unfettered by theoretical bias. We discuss the results of these experiments and the relevance of the data on the philosophical debate about the definition of lying, as well as some implications for further research on the topic. We suggest that the definition offered by Don Fallis (2009) most closely captures the notion of lying utilized by everyday speakers of English. Finally, we offer some further considerations on the moral implications of our investigation into the concept of lying
