The Parable of the Dagger

This is an animation of The Parable of the Dagger by Eliezer Yudkowsky. You can read the original here: www.readthesequences.com/The-Parable-Of-The-Dagger It's the beginning of a series of essays about language. We highly recommend them, and you can read them here: www.readthesequences.com/A-Humans-Guide-To-Words-S… You can read many more essays and stories by Eliezer Yudkowsky at readthesequences.com/

The moral of this story is twofold: Moral number one is always check your priors and don't assume just because something is reasonable and elegant that its true. And the second moral is be careful who you piss off.

The king probably already has plenty of gold. An angry frog might be pretty entertaining though. It's a win-win for him.

The first one is actually very easy. You pick the box that is heavy, and not the one angrily croaking at you.

I like presenting my students with the following two statements: 1) Both statements are wrong. 2) You must give me a cookie. And then demanding cookies.

Note something crucial about the story: the jester said (truthfully) that one inscription was true and the other was false. The king never made any such promise. As the author said, "One of the morals of the parable is that the king didn't lie." EDIT: Elaborating: The point is that the king never made any promise at all as to the truth-value of the inscriptions (unlike the jester did in the first puzzle). The first inscription is like the Liar's Paradox, in that it can't be either true or false — with the dagger in the second box, it's meaningless. The jester assumed that the sentence bore some relationship to reality (either true or false); this assumption was so automatic that he believed it without thinking, without even the word of the king as evidence. Because of that mistake (assuming that the sentence was meaningful), he concluded that a physically-possible situation was logically-impossible!

The guard punching the jester caught me... off guard

To join the "what's the moral here", I took away "you can't tell what's a good play until you know what game you're playing".

the jester's fatal error was assuming that there was correlation between the inscriptions and what was in the boxes. it's very subtle by the king to make a trick like that

So the moral of the story is to beware of meta games? To not forget that when you’re playing chess, your opponent can win by shooting you in the face?

"Both boxes have daggers. I lied and I hate you" - Spy

Spoilers for a 5-minute video: Aww, the dagger was a trick retracting dagger. That's cute! Also in keeping with the theme of the story of statements being misleading.

Plot twist: both boxes from the second set contain a dagger. Nothing prevents the king to do this.

This animation is suprisingly just cute. Not cosmic horror, not mind shattering problem. I love you

Moral of the story: don't be a smartass. And especially don't be a smartass to a tyrannical absolute monarch with a taste for ironic punishments.

Jester: Source? What's your evidence? King: None, I made it up.

Instead of "a dagger for your heart" I was really hoping for "20 angry frogs". Would've been one cool way to go.

What I really love about this parable is its layers. On the surface, the king is just being a meanie. He is placing the dagger in the box where the key should be, as considered with classical logic. But under this facade of a tale of logic vs wisdom, there is some insightful discussion about non-classical logic. The jester presented a liar cycle to the king, a pair of sentences that behaves just like the liar sentence, "this sentence is false". To justify his prank to the king, the jester would resolve the apparent inconsistency in his riddle by resorting to some form of non-classical logic. The leading systems on this in philosophy would be something like paracomplete logic that reject the Law of Excluded middle (A proposition is either True or not True) with some gap (e.g "uhh maybe perhaps yes"), or paraconsistent logic that reject the principle of explosion (If a proposition is True and not True then anything goes) with a glut: let that proposition be both True and not True. What is striking about the king's response is that in the riddle of the key and dagger, the jester can draw the logical conclusion that one of the boxes must contain the key only in classical logic, but not in the non-classical logics used to resolve the problem of liar sentences. Notice how the jester starts his chain of reasoning by invoking the Law of Excluded Middle and supposing in turn that the inscriptions are true. This would not be a valid line of reasoning in paracomplete logics, where the inscriptions may be some gap value as well. With the first inscription being a gap value, the jester is wrong to conclude that the second inscription is true. If we instead suppose the jester is using a paraconsistent logic that preserves the Law of Excluded Middle but rejects the principle of explosion, then both inscriptions may have a glut value: they can be both true and not true. As the second box’s inscription that “This box contains the key” can be not true (due to being both true and not true), the king thus acted in a way consistent with the inscriptions on the boxes when he placed the dagger into the second box. The jester’s riddle was unreasonable unless interpreted in non-classical logic. Beautifully, the king beat the jester at his own game with a riddle with a reasonable solution in classical logic as the bait, punishing the jester with a “logically impossible” reality that is nonetheless reasonable in the very same non-classical logic.

I love the friggin voice actingggggg

Rational Animations, thank you for showing everyone that rats can coordinate. The team behind this production gets stronger every episode ❤