A statement constitutes a lie only if at least one of the interlocutors knows it to be untrue, yet insists or assumes that it is true. If all the parties involved in the exchange know that the statement is false or if none of them know whether it is false or true, then it is fiction or an act of faith.
Lies are about facts or about states of being. Lies that pertain to facts cannot be rendered true by widespread consensus. But with regards to lies about states of being, if the parties agree something to be the truth their agreement can make it true (alter its truth value). This is so because statements about states of being are dependent on social context.
Lies either prompt action or inhibit it. Sometimes, actions taken can convert the lie into a truth (self-fulfilling lie).
There are eight types of lies:
Confabulations are an important part of life. They serve to heal emotional wounds or to prevent ones from being inflicted in the first place. They prop-up the confabulator’s self-esteem, regulate his (or her) sense of self-worth, and buttress his (or her) self-image. They serve as organizing principles in social interactions.