To lie is to make statements that are untrue, whether or not the falsity of such statements is known by the speaker. A lie can be a genuine falsehood or a selective truth, a lie by omission, or even the truth if the intention is to deceive or to cause an action not in the listener's interests.

Table of contents
1 Morality of lying
2 Psychology of lying

Morality of lying

Lying is against the moral standards of many people and is specifically prohibited as a sin in many religions. Ethical traditions and philosopers are divided over whether a lie is ever allowable but are generally opposed - Aristotle said no, Plato said yes, Saint Augustine said no, Kant said no.

Lying in a way that escalates rather than de-escalates a conflict is usually considered the worst sin.

A liar is a person who is known to have a tendency to tell lies. People's tolerance for liars is generally very small, and it is often only necessary to be caught lying once to be labelled as a liar and not trusted again. This is of course moderated by the importance of the matter being lied about.

Paradoxically, a big lie is often easier to get people to believe, and more difficult for them to challenge even when facts support it. Propaganda is often based on choosing some very large but comfortable lie which is hard to challenge for social status or other reasons - and spreading this throughout a whole society.

Etiquette of lying

Etiquette is largely concerned with questions of lying, blaming and hypocrisy - things often decried in ethics but of great utility in society:

The moral reasons to tolerate lies have mostly to do with avoiding conflict. An ethical code will often specify when the truth is required, and when not. In courtrooms, for instance, the adversarial process and standard of evidence that applies restricts questions so that the need for a witness to lie is reduced - thus the truth on the matter at hand is supposed to be more easily revealed.

The need to sometimes lie is recognized in the term white lie (or officious lie), where the lie is harmless, and there are circumstances where there is an expectation to be less than totally honest through necessity or pragmatism. Lies can be divided into classes - injurious or malicious, officious, and jocose, of which only the first class is serious (Catholicism classes the first as a mortal sin but also condemns the others as venial).

Paradox of lying

Lying is the subject of many paradoxes, the most famous one being known as the liar paradox, commonly expressed as "This sentence is a lie," or "This sentence is false." The so-called Epimenides paradox -- "All Cretans are liars," as stated by Epimenides the Cretan -- is a forerunner of this, though its status as a paradox is disputed. A class of related logic puzzles are known as knights and knaves, in which the goal is to determine who of a group of people is lying and who is telling the truth.

Much ethical dilemma is based on related ethical paradox on issues of lying. Some famous ones include the question of whether anyone, hiding refugees from an oppressive and racist government, might owe the truth to an official who comes asking where they are.

Psychology of lying

The capacity of hominids to lie is noted early and nearly universally in human development and language studies with Great Apes. One famous lie by the latter was when Koko the Gorilla, confronted by her handlers after a tantrum in which she had literally torn a steel sink out of its moorings, signed in American Sign Language, "cat did it", pointing at her tiny kitten. It is unclear if this was a joke or a genuine attempt at blaming her tiny pet.

Evolutionary psychology is concerned with the theory of mind which people employ to simulate another's reaction to their story and determine if a lie will be believable. The most commonly cited milestone in the rising of this, what is known as Machiavellian intelligence, is at the human age of about four and a half years, when children begin to be able to lie convincingly. Before this, they seem simply unable to comprehend that anyone doesn't see the same view of events that they do - and seem to assume that there is only one point of view - their own - that must be integrated into any given story.

Sociology and linguistics of lying

Lying and blaming are so basic to society that it is hard to formally study them. George Lakoff, in criticizing some claims of George W. Bush made prior to the 2003 invasion of Iraq, notes that "Are they lies - or are they merely exaggerations, misleading statements, mistakes, rhetorical excesses and so on. Linguists study such matters. The most startling finding is that, in considering whether a statement is a lie, the least important consideration for most people is whether it is true! The more important considerations are, Did he believe it? Did he intend to deceive? Was he trying to gain some advantage or to harm someone else? Is it a serious matter, or a trivial one? Is it "just" a matter of political rhetoric? Most people will grant that, even if the statement happened to be false, if he believed it, wasn't trying to deceive, and was not trying to gain advantage or harm any one, then there was no lie. If it was a lie in the service of a good cause, then it was a white lie. If it was based on faulty information, then it was an honest mistake. If it was just there for emphasis, then it was an exaggeration."

"These have been among the administration's defenses. The good cause: liberating Iraq. The faulty information: from the CIA. The emphasis: enthusiasm for a great cause. Even though there is evidence that the President and his advisers knew the information was false, they can deflect the use of the L-word. The falsehoods have been revealed and they, in themselves, do not matter much to most people."

The philosopher Leo Strauss, who had a major influence on many of the figures in the Project for a New American Century who dominated the administration during this period, stressed the necessity of lying in order to conceal a strategic position, or to aid diplomacy. So did earlier figures in political philosophy back to Niccolo Machiavelli.

It seems extremely unlikely that lies will ever be entirely eliminated from politics or diplomacy, just as they cannot be removed from the warfare that these activities are, ultimately, supposed to help pre-empt.

Lies and trust

One reason that lying may persist as a strategy in social settings is that it is not the comparison of the facts against some abstract notion of truth, but rather, the assessment of whether or not a betrayal of trust has occurred, that determines the response to a lie.

In the case of the Iraq war, for instance, the fact that lies escalated a conflict may have made it a quite serious breach of trust and betrayal of those who would suffer in that conflict. However, anyone who accepts as true the assertion that the regime in place was an inevitable threat to those who perished fighting it, or whose lives are at risk in the aftermath of the invasion, would be far less likely to consider escalating the conflict at the most convenient time to be any kind of betrayal. The perspective of the common sense conservative quite often relies on this kind of assumption of certainty. But if conflicts that are to be escalated are chosen due to some ideology, it is hard to see how this differs from simple might makes right logic.

See also: The Boy who cried Wolf, Prisoner's dilemma, Bullshit

Lie or lie down also means to rest horizontally on a surface, such as a bed. See Human positions.

Lie (pronounced as "Lee") is also a family name. Notable persons with this lastname including Sophus Lie, the founder of Lie algebra.