Talk:Crocodile dilemma

The paradox does not state that the crocodile will return the child ONLY if the father is correct...

That is correct -- see the given sources for this paradox. Therefore I changed it accordingly. --Vicki Reitta (talk) 15:18, 28 August 2011 (UTC)

Solution?

There are two solutions no one has touched upon yet; to avoid the obvious implications of the "will he/ won't he" decisions. First and foremost, neither of the obvious answers take into account the trustworthiness of the crocodile. It's an unknown, and that factors into the paradox. If the parent guesses that the crocodile will return the child, there is no assurance that this is true and the child will in fact be returned; hence why the epithet of the problem is the "liar paradox." The simplest way out is to take the power out of the crocodile's/ liar's stance by avoiding the two most obvious conclusions. An example of this would be to kill the crocodile, and avoid answering the paradox altogether. The other, lesser-known answer is to turn the paradox back onto the crocodile; give the liar a paradox he himself can't answer. For instance, let's say the parent offers themselves as a hostage in the child's stead, offers to feed the crocodile and teach it to hunt. Faced with the choice paralysis of hope/fear; learning a new method and perchance changing its nature, the crocodile flees.172.223.22.48 (talk) 01:08, 6 December 2023 (UTC) SpeSalvi

If the Crocodile decides to KEEP the child, and the Father predicted the child would be KEPT then the outcome is A PARADOX. - Nope, the father guessed correctly, the child is returned. Similarly If the Crocodile decides to RETURN the child, and the Father predicted the child would be KEPT then the outcome is A PARADOX. - The father guessed incorrectly, the child is kept. — Preceding unsigned comment added by 89.241.198.210 (talk) 11:39, 17 April 2012 (UTC)

"you will prove me wrong" —Preceding unsigned comment added by 71.13.180.1 (talk) 21:29, 10 February 2010 (UTC)

or if the father says "you will not return my child", the crocodile could tell the father where the child is and not return the child himself. —Preceding unsigned comment added by 99.225.195.42 (talk) 21:11, 18 September 2010 (UTC)

"Correct. Immediately after asking you this question, my action will be to not return your child. Then, after hearing your answer, and you having correctly guessed the action immediately following the asking of my question, I will return your child to you." (71.122.67.95 (talk) 21:41, 6 October 2010 (UTC))

I'm not sure I understand fully why this paradox exists. The crocodile cannot simultaneously decide what he's going to do with the child beforehand, AND base what he's going to do with the child on the outcome of what the father says. That's like me saying "I'll definitely not give you any icecream, and I'll give you some icecream if you guess (anything). The crocodile is contradicting himself by saying he's going to do two things at once. Alexbrainbox (talk) 22:19, 26 August 2011 (UTC)

Why, the crocodile will sponaneously burst into flames, of course. 61.68.133.67 (talk) 10:35, 15 October 2011 (UTC)

I do not think that this is a paradox. The problem itself states that there is ONE condition that must be met for the child to be returned and that is if the father guesses the will of the crocodile correctly. If there truly is only one condition that needs to be met, then there is no paradox. — Preceding unsigned comment added by 24.146.1.230 (talk) 14:51, 1 November 2011 (UTC)

The parent should say "you will act in a way that surprises all who hear of it" Lynflow15 (talk) 11:57, 3 September 2017 (UTC)

Similar paradoxes

This Paradox was simmilarilly used in Deltora Quest - A giant is going to kill a boy, but the boy decides how he will die. The boy must make a statement, and if that statement is true, the giant will strangle the boy with his bare hands, but if the boy lies, his head will be cut off. the boy then states "my head will be cut off." thus creating the paradox I believe that the above paradox does not exist, because the giant then simply strangles the boy, then beheads him. but the DQ Anime fixed such a problem. They said that if the boy lies, the giant will kill the boy with his sword, and if he speaks the truth, the giant will kill the boy with his bare hands, in such a paradox, the boy may say "I will be killed by your sword." thus creating a paradox.

Redundant paradox

How is this any different from the two-sentence liar paradox? —Preceding unsigned comment added by 69.248.123.28 (talk) 13:20, 3 August 2010 (UTC)

Metaknowledge

Why are the three assumptions inconsistent when tested in combination? The source[2] referred to doesn't deal with the topic at all. —Preceding unsigned comment added by 178.203.177.120 (talk) 10:57, 15 August 2010 (UTC)

See here. Inexplicably, Google Books has attached incorrect book information to a scan. Compare the front covers. I've fixed the reference. —Anonymous Dissident^Talk 12:26, 29 August 2010 (UTC)

I wanted to know this myself, but unfortunately the book simply references another source which I don't have access to.

I'm skeptical that the statements are inconsistent for this reason: if we were to define "x is known to be true" to mean "x is true", then the three statements would be tautologies; how then is it possible to derive a contradiction from them? 131.111.184.8 (talk) 22:38, 10 October 2010 (UTC)

I don't know how it is inconsistent either (and don't link to a Google books or Google anything please, in answering me). However, the third statement does look wrong. It seems to me that it should be: (iii) If it is known that ρ implies σ, and ρ is known to be true, then σ is also known to be true. --Zzo38 (talk) 05:26, 9 September 2013 (UTC)

I have just come across this article, and like the users above I wondered why three assumptions are inconsistent in combination. Indeed, depending on how they are interpreted, they must not be inconsistent: (i) is a theorem of epistemic modal logic, (ii) is also a theorem of epistemic modal logic, and (iii) is also a theorem if it is interpreted as the following form: If "p implies q" is a tautology, then "p is known implies q is known" is a tautology. Another version of (iii) which is a theorem is: if "p implies q" is known and p is known then q is known.

I do not doubt that the original source shows some impossibility theorem. What is missing is exactly what impossibility theorem is shown, and an actual direct reference to the information. I followed the citation to Springer-Verlag Lecture Notes in Artificial Intelligence (subtitle: Natural Language and Logic, International Scientific Symposium Hamburg), and in turn tried to find Richard Montague (1960). Unfortunately they do not seem to say in the Lecture Notes which paper exactly they are citing -- it isn't in the bibliography. And, very unfortunately, Philpapers lists twelve different publications by Montague from 1960. Philpapers link

Therefore, I can't find the original reference where Montague proves such a result, and more importantly the nature of the result needs clarification. Overall, this article needs attention from an expert on epistemic logic.

In light of all of this I am tempted to make the statement disputed or at least indicate that the footnote is not direct. Cstanford.math (talk) 01:19, 2 November 2017 (UTC)

EDIT: Found it. Turns out that I did overlook the reference. It's Montague, R. [1960] "A Paradox Regained", in Thomason, R. (ed) [1974] Formal Philosophy, Selected Papers of Richard Montague, Yale University Press.

In "Formal Philosophy: Selected Papers" July 18, 1974 by Richard Montague, I then found chapter 9 "A Paradox Regained (with David Kaplan)". The paper is quite technical and I cannot, at a glance, find the exact impossibility theorem that is proven. But I will let the claim stand (as reported in the other citation) that the result is as stated. Cstanford.math (talk) 01:37, 2 November 2017 (UTC)

Unsolved vs Unsolvable

Do we really know it's is unsolvable? I mean, is it proven that there will never be a solution ever? Perhaps a better phrasing in the opening line is "unsolved". 58.160.33.191 (talk) 06:45, 3 March 2011 (UTC)

Independence Solution

The Crocodile dilemma is a paradox only if the outcomes (KEEP child or RETURN child) are disjoint or mutually exclusive. However, let's suppose that the Crocodile is able to do both or neither, keep the child and return the child. If the father guessed that the child would be kept, there is no paradox since the Crocodile could do both, physically possible by mutual possession of the child. However, if the father guessed that the child would not be returned, since the return of the child is promised on a correct answer, then the paradox continues unless temporal discretion is used. — Preceding unsigned comment added by Kodiak42 (talk • contribs) 01:37, 21 February 2013 (UTC)

The crocodile marries the father and they raise the child together. Paradox resolved. 00dani (talk) 21:09, 23 March 2017 (UTC)

An illustration of the uselessness of navel-gazing philosophy

In the actual world of physical reality, everyone knows that when a crocodile grabs a child the child is drowned and/or dismembered within seconds. The real dilemma here is "Why are philosophers given any respect and/or attention?" — Preceding unsigned comment added by 71.178.166.3 (talk) 01:52, 13 October 2020 (UTC)

Déjà Vu

This paradox seems very familiar. I remember reading about a paradox exactly like this, but with a different scenario. I believe Plato was crossing a bridge, and Socrates threatened to throw him off, and then asked Plato to predict whether he would throw him off. I do not remember the name of this paradox, but I know it was on Wikipedia already. Perhaps the two pages could be merged. (96.241.99.48 (talk) 01:32, 28 October 2020 (UTC))

Oh. I just found the page: Buridan's bridge. The scenario is actually very different, but the same logical paradox emerges. Basically, it's the same paradox but with a different backstory. (96.241.99.48 (talk) 01:36, 28 October 2020 (UTC))