In Liar Liar (1997), Jim Carrey becomes unhinged by a magical force compelling him to tell nothing but the truth for 24 hours. The essential elements of this premise go back many years. Early films that used the premise include Pimple Turns Honest (1914) and Billy the Truthful (1917).
The ancient tale "The Boy Who Cried Wolf" was a cautionary fable about the value of telling the truth. The shepherd boy at the center of the story raises the ire of villagers for his repeated lies. But Frederic S. Isham turned this tale on its head with his 1914 novel "Nothing but the Truth." The novel involves a man who, by entering into a "truth pact," puts himself at dire risk of offending others in his social circle. His predicament is summarized by the following passage:
To tell the truth - to blurt out nothing but the truth to every one, and on every occasion, for three whole weeks - that's what Bob had contracted to do. From the point of view of the commodore and the others, the man who tried to fill this contract would certainly be shot, or electrocuted, or ridden out of town on a rail, or receive a coat of tar and feathers.The book's protagonist, Bob Bennett, is an idle young man from a rich family. When his father tells him that the family has lost their fortune, Bennett becomes desperate to make money and he cannot resist when this sizable wager is offered to him. He spends a weekend as a guest at a country estate and finds an array of upper class guests (including a stuffy judge and a facetious bishop) increasingly irritated by his frank remarks. He comes to realize that lies are required in social interaction to avoid unnecessary conflict. Bennett also comes to realize that people don't always believe the truth when they hear it. His fellow guests assume that his statements reflect either a vigorous sense of humor or a perilous state of sanity. Bennett finds one person after another "[throwing] cold glances his way for the faux pas he made." A woman holding a small dog asks Bennett if he thinks small dogs are adorable. He tells her, flatly, that he does not. The woman shrinks away from him as if he is dangerous. He makes a particularly big mess when, during a conversation with the wife of a friend, he admits that the friend and he had visited a cabaret with a pair of showgirls.
The book was adapted into a Broadway play in 1916. The story was changed extensively. Unlike the book, the play was more farcical than meditative. Bennett, a rising young stockbroker, is so determined to prove to his boss and other brokers that it isn't necessary to lie to sell stocks that he bets $10,000 that he will tell nothing but the absolute truth for the next 24 hours. The playwright, James Montgomery, made a point to shrink the three weeks to 24 hours to increase the tension and speed up the pacing. Also, he gave Mr. Bennett a job as a stockbroker to make his efforts more challenging. In the book, Bennett never seems to be at much risk as he putters around the golf links of a lavish country estate. Montgomery escalated the tension even further by making it that the money Bennett has bet belongs to his fiancée's charity.
The play's popularity inspired Paramount Pictures to produce a film adaptation in 1929. The film version, which cast Richard Dix as Bennett, did not stray far from the play. The studio remade the film with Bob Hope in 1941.
In time, truth-telling driven by stern will and financial incentives gave way to truth-telling driven by overpowering drugs and spells. An injection of truth serum is responsible for Dagwood Bumstead (Arthur Lake) being only able to speak the truth in Blondie Knows Best (1946). Darrin Stevens (Dick York) is compelled to tell the truth by a magical statue in the Bewitched episode "Speak the Truth" (1965). In the comedic Twilight Zone episode "The Whole Truth" (1961), a haunted car makes whoever owns it tell the truth.
Liar Liar was designed as yet another remake of Nothing But the Truth. Now, the protagonist was made a high-priced defense attorney (probably because high-priced defense attorneys were seen to be lacking in credibility after the O.J. Simpson murder trial). The lawyer's son, Max, is so distressed by his father's compulsive lying that he uses a birthday wish to prevent his father from telling a lie for an entire day. Carrey finds that his new-found honesty puts him at great disadvantage at trial. Carrey is experiencing excruciating pain as he struggles to get out the lies needed to win his case. He could not be more desperate and anguished when he finally screeches to the befuddled judge, "I can't lie!"
Contrary to Carrey's character, a man with an extraordinary inability to lie, is the character that Ricky Gervais plays in The Invention of Lying (2009). Gervais' character is extraordinary in that he is the only man in his world who can lie. The Invention of Lying finally takes us to the opposite end of spectrum, from the "Boy Who Cried Wolf"'s protestation of lying to a shameless and sniggering celebration of lying. The film was not well-received, which may mean that we are not yet cynical enough as a society to give up on the truth.