When is it Okay to Swear?

Everyone who watches courtroom dramas is familiar with the swearing in of witnesses. “Do you swear or affirm to tell the truth, the whole truth and nothing but the truth?” But, why do we do this? How did this practice come about?

The truth is essential to our concept of a fair trial. To convict someone of a crime or enter a judgment against them based on lies is not a good way to run a railroad. So we have the witness sworn in to tell the truth, which then places them under an obligation not to lie or tell half-truths. Violation of that oath is the crime of perjury, which is its own crime. But how did we come up with this practice? There are a lot of details about the origins of this practice we don’t have time for here, but for our purposes it safe to say it all has to do with belief in Heaven, Hell, God and the afterlife.

The oath was born in a religious world that believed in an actual hell, divine wrath and that God would punish those who lie and tell untruths. The oath therefore was taking an oath not to the Court but to God, that you would tell the truth. If you broke your oath and lied, God would punish you with damnation and hell. An interesting result of this was that atheists were not allowed to testify in court. They could not be trusted to tell the truth because they did not believe in a God that would punish them for false testimony.

Another interesting result was that the accused was forbidden from testifying in a criminal trial. In an age when torture, and execution were common punishments, it was decided that the temptation of an accused to lie was so great to save himself from execution or torment that it would put the accused’s soul in danger to allow him to testify. In other words, it was better that an innocent man be executed rather than risk his soul going to hell in the event he committed perjury. Interestingly, this practice of barring the accused from testifying in his own defense remained in place in most jurisdictions in the U.S. until late in the 19th Century or early in the 20th Century.