“I’ll tell you as much truth as the people who wrote that fuckin’ book!” -George Carlin

There’s a whole history there!

In short: swearing on the Bible doesn’t stop you from lying, it makes God angry at you if you do.

Long answer: When you swear or solemnly affirm to tell the truth, the whole truth, and nothing but the truth, you are making a legal commitment not to lie; if you lie under those circumstances, you are committing the crime of perjury.

But what if somebody was to deny they swore an oath? That’s why we have witnesses, and there is no better witness than a god. (Actually, the difference between an oath and a pledge is that an oath is formally witnessed by at least one god. A vow, meanwhile, is a promise made to a god).

So when a Roman swore an oath, he announced his name and the god he was swearing by; that got the god’s attention, and since gods see everything, the swearer will be punished if he violates the terms if the oath. You know how in movies a character will tell an obvious lie and declare “and may God strike me down if I lie”, whereupon something immediately hits them on the head? That’s how oaths actually work.

Likewise, swearing an oath while touching something related to the witnessing god makes the oath even more powerful and binding. Thus, you don’t want to break an oath sworn by Jupiter, and you really don’t want to break an oath sworn in a temple to Jupiter with your hand on a statue of Jupiter.

Instead of swearing by Jupiter (or Odin, or Ra, or Enlil, or whoever), Christians swear by God, and touch a Bible to make their oath stricter. Muslims use the Qu’ran to the same effect.

It obviously doesn’t, and people do lie in court all the time in both fiction and reality. The bible, or whatever they happen to use as a stand-in, is just ceremonial for the oath of sworn testimony. The real threat that keeps people from lying is not hellfire and damnation, it’s perjury.

And that’s why perjury exists as a crime. Or the right to refuse to testify against family members (depends on your location). Or the right to shut up lest your testimony incriminate yourself.

Most people testifying in court have not committed crimes. They will be suitably impressed with the seriousness of it all so they won’t lie.

95 percent of court proceedings are fucking boring. Even in most big cases. That’s why writers fluff it to to keep viewers viewing and readers turning pages. It’s not like that.

It doesn’t, and people do lie in court. It’s a relic of a time when people supposedly were afraid of going to hell.

Me: “I fucking swear to tell the fucking truth and nothing but the fucking truth so help me cunt”

Judge: “get him out of here”

It’s a social more, nothing more ;)

In other words, it doesn’t matter what you swear by, it’s the open swearing that matters in terms of legality. See, the oath is what makes perjury prosecution “acceptable”. When a witness is sworn in, the process isn’t so much about them actually promising to tell the truth as it is a warning to them that truth is expected and will be enforced.

Yeah, historically, there’s more to it than that, but it boils down to everyone involved knowing that truth is expected, and lying comes with consequences (well, if you get caught at it, and can’t avoid those consequences in some way. The system ain’t perfect at its best, and is rarely at its best).

Swearing on a bible is just tradition based on centuries of christians and christianity being in power. You can opt to “affirm” instead, giving an non religious oath that is just a binding.

But, in any real terms, an oath isn’t necessary to begin with. When the system/state/government/people have the power to punish you for lying, they don’t even really have to notify you that lying will come with consequences. Doing so is a nicety that at least prevents anyone from being able to say they didn’t know they couldn’t lie. Not that trying it in the absence of an oath would be worth spit, but it saves time.

But having an expectation of truth under duress is a cultural thing. And it can be a form of duress. You can be compelled to appear and give testimony, with consequences got refusing. In other situations, being under duress can be a defense against a charge, though the standard for what degree of threat serves to meet that criteria is pretty steep. But it’s an understood thing that you aren’t supposed to lie during legal proceedings. It doesn’t have to be that way, but it certainly does make it easier to have a degree of conformity to the truth among people that might otherwise lie.

it is a real threat.

there are different tiers of punishment for lies. if you swore to tell the truth, but demonstrably lied, this will f up your life further.

https://acoup.blog/2019/06/28/collections-oaths-how-do-they-work/ has a very interesting discussion and you should read it all. Not everything applies to modern world but the majority does

Swearing on the bible isn’t to prevent you from lying, it’s putting the “no more lying from this point onwards” into effect, in other words activating the perjury rule.

They use it in other ceremonies like swearing in the president but they let people use different books for that - maybe they let people use any book for the court too? So even if the bible has no special place in your heart you’ll be vowing before whatever god you follow or whatever book is most beloved to you. Unless you lie about that bit, too 😉

It’s not smart to lie in court. What’s smart is to answer a question in a way we’re you’re not lying but not giving them the info they want, assuming you or a loved one is the one being prosecuted. After all, they’re commonly trying to GET YOU to lie, because they have evidence which would contradict your lie, and this the guilty party becomes more likely to be guilty, in the jury’s eyes.

Deeply religious folks often believe that if you swear on a bible to tell the truth, then lie, you’ll go to hell. If you aren’t religious, it means nothing. For others it’s a spectrum in between.

I mean, I would just swear on Carl Sagan’s The Demon Haunted World.

It’s actually not so realistic, except for transactional justice.

It works if you believe your religion. If you are a roman swearing by Jupiter you are asking Jupiter to strike you with lightening if you lie - and as a believer you honestly think that will happen. since most people are christians they swear on the bible knowing they are asking to go to hell if they lie - even if otherwise they are good enough to be forgiven. Muslins generally swear of the quarn - to similar reasons (i’m not clear on what muslins believe happens if they lie, but they believe in it which matters)

of course a large number of people are not religious these days - so this is often pointless.

And the prosecution will find this post and show it to the judge or jury in an extremely large font

Edit: that wasn’t meant to be threatening… Just commentary on the state of things. IF you were in a compromised situation, they would use it against you.