Lying may be defined as the making of a declarative statement to another person that one believes to be false, with the intention that the other person believe that statement to be true, and the intention that the person believe that one believes that statement to be true. Lying may be distinguished from other forms of intentional deception insofar as it involves the use of conventional signs arranged to make a statement. Intentional deception using natural signs, such as fake smiling, shamming a limp, or wearing a disguise, does not count as lying. Intentional deception using conventional signs that are neither spoken nor written, such as deceptively nodding one's head, sending deceptive smoke signals, or deceptive signaling by semaphore, does count as lying, at least insofar as one is making a statement.

Lying requires that a statement be made; hence that form of deception that consists in withholding...