The Truth About Lying

Lying is a common human phenomenon. It is very difficult, if not impossible, to find an adult who does not tell lies (at least once in a while). Most people tell lies all the time. St Augustine wrote a short but profound treatise on lying (De Mendacio). What makes a statement a lie is the intention to deceive.

According to Augustine, “ a man lies who has one thing in his mind and utters another in words or by signs of whatever kind.”  In order to deceive a liar must have what St Augustine calls ‘double heart’.  The liar’s double heart consists of two things. First, what he knows or thinks to be true and he decides not to say. Second, what he says knowing or thinking that it is false. He defines truth as “that which sets free from all error” and falsehood as “that  which entangles in all error.”


Not All Falsehood Is A Lie

St Augustine argues that not everyone who makes a false statement tells lies. If person says something that is false while he believes it to be true in his heart, he is not telling lies. The person who makes false statement believing it to be true is not telling lies because he has no intention to deceive; he does not have double heart because what he says corresponds to what he believes.

Though he is not telling lies, he is in error. “His error lies in the fact that he believes what he should not believe or thinks he knows what he does not know.” St Paul teaching strict observance of the law as means of attaining salvation was not lying. He truly believed what he taught. He later realized that he was in error.


A True Statement Can Be A Lie

It is also possible to say something that is true and still be guilty of lying. A person that makes a true statement believing it to be false with the intention of deceiving is actually lying. He believes something to be false in order to deceive though what he says turns out to be true.

If John says he is the son the president in order to deceive and defraud, without knowing that he is actually the lost son of the president. He is lying though his statement is true. When he utters the statement he believes in his heart that it is false, though he utters it as true. He has a ‘double heart.’ There is a dichotomy between what he believes and what he says.


Truth Sets You Free

Whether a person lies or not does not depend on the objective veracity or falsity of his statement. What determines whether a person lies is his state of mind- his intention to deceive. When a person has an intention to deceive, whether what he says is true or false, he is lying. Veracity or falsity is a matter of logic. Lying is a matter of morality. The intention to deceive is immoral. Only the truth can set us free (Jn 8:32).