In the make-believe world of The Invention of Lying, everyone strictly obeys God’s ninth commandment. Alas, in spinning this ambitious morality play, the filmmakers violate a screenwriting commandment: thou shalt not get cold feet in the third act.
The characters are truthful not because they want to be; they just don’t know any better. Their DNA doesn’t permit them to lie to their spouses, call in sick when they’re feeling fine or tell their children that Santa is real. Of course, this also means they can’t fudge the truth to spare others’ feelings.