Talk:Paradox/Archive 1

Latest comment: 12 years ago by Beeblebrox in topic Proposal to merge Paradoxology
Archive 1

removals

Hey, please remove items in the article that do not belong - that are not paradoxes or paradoxical. The "Monty Hall Problem", for example, is not a paradox. It is not understood as one for those familiar with the problem, and it clearly does not fit the definition as stated in this Wikipedia article or elsewhere. In this case, even though many people "fall for it", it is a clear mathematical problem with a clear, logical, unambigious solution. Lets keep the list for paradoxes only!


193.203.83.xxx for which Newcomb that paradox stands for. The American astronomer? XJam [2002.03.26] 2 Tuesday (0)

Yes. He told the paradox to philosopher Robert Nozick, who introduced it to philosophers (with proper accreditation) in a 1963 essay called "Newcomb's Paradox and Two Principles of Choice." or some such.

There are various formulations given the name Control paradox.

One is the statement that "Man can never be free of control, for to be free of control is to be controlled by oneself".

External Links:

Half of the links in above list are either dead or online-shops are link farms. So what's the idea of this? Pjacobi 18:52, 15 Jul 2004 (UTC)

All paradoxes can be resolved. If there were an actual contradiction in the world, the world wouldn't exist (at least mathematically speaking) :-) AxelBoldt 02:09 Nov 11, 2002 (UTC)

Congradulations, the world doesn't exist. Thank you, come again.

Even the Liar paradox? I thought that one was a no-go.Cyan 07:40 Apr 12, 2003 (UTC)

I have a feeling that even the Liar paradox has a resolution in the real world, albeit a quantum one involving a superposition of lying and not-lying. -- Derek Ross
"This statement is false." seems to be an example of a paradox. The misunderstanding is simply an implicit assertion that all statements contain, that assertion being "This statement is true". When taking into the implicit assertion the statement becomes "This statement is true and this statement is false." A. N. Prior is credited with the solution to this example.
The liar paradox involves "pure states" that form a discrete set, whereas in quantum mechanics, my (completely non-expert) understanding is that the set of pure states is always continuous. Unless lying and not-lying can be embedded in some sort of continuous space, I find it implausible that QM could provide a resolution. (The question of observable quantities and appropriate measurements would also need to be resolved.) My feeling is that the liar paradox is a demonstration that some propositions of classical logic are non-Aristotelian, i.e. are neither true nor false. The existence of the liar paradox demonstrate the limits of classical logic in the same way the existence of Godel statements demonstrate the limits of formal systems of number theory. Cyan 06:33 Apr 21, 2003 (UTC)


I think the predestination paradox deserves to be listed separately from the grandfather paradox; although the examples used are similar, the point is different. The point of the predestination paradox is that the fact that you exist in the first place means that you are predestined to travel back in time and impregnate your great-great-grandmother. If you don't do it, you can't exist, so the fact that you do exist means that you must do it; you have no choice; it's going to happen. That idea is not present in the grandfather paradox. -- Shammack 17:59 Apr 20, 2003 (UTC)

From my reading of the grandfather paradox article, the predestination paradox isn't the topic at all. Only the line
"To avoid the getout of the time traveller being his own father, which would be possible genetically, though statistically unlikely, this would have to take place several months prior to his own conception."
suggests something like your "predestination paradox", and then only to state that it isn't the point of the article. So I think the predestination paradox does indeed need its own article. Go for it. Cyan 06:33 Apr 21, 2003 (UTC)

15/04/05 - for the grandfather paradox to work the killer has to exist, yet he can't. Since both these states MUST exist at the together surely there is a quantum solution? In which case the disruption of the time space continuum creates two universes and thus the time traveller travels to an alternate reality AS WELL AS time travelling in that reality. Travelling forward in time his grandfather would be dead, but then again he IS BORN in an alternate timeline!!!!!!


Isn't "Quin's Liar Paradox" the same as the normal "Liar Paradox"? user:J.J.

The difference is that Quine's is a predicate rather than a sentence. it is not itself false or true, butit yields falsehood when it is appended to its own quotation. That is:
(1)Yields falsehood when appended to its own quotation

is merely a predicate, which could be meaningfully applied to any expression. For example,

(2)"is a frog" yields falsehood when appended to its own quotation

is true, because

(3)"is a frog" is a frog

is false.The interesting case, of course, is whether the predicate is true of itself. what about:

(4) "Yields falsehood when appended to its own quotation" yields falsehood when appended to its own quotation.

Does it? Is 4 true or false?


I really want to separate the list of paradoxes into groups... Sociological/psychological paradoxes, Paradoxes of logical systems, Paradoxes of definition, Paradoxes of intuition, Paradoxes of physics, etc. The problem is that there are often no clear boundaries (especially counting paradoxes of intuition, which could be considered to contain everything). Yet some clearly fall into one group. Is this a meta-paradox? More importantly, is categorization possible? Paullusmagnus 22:11, 1 Oct 2003 (UTC)

Give it a shot. The people who care are watching this page. -- Cyan 22:14, 1 Oct 2003 (UTC)
And a fantastic job you have done! Before it was just a long list of paradoxes. Now it has structure and form in a way that allows one to grok the whole paradox space simultaneously. Good work Paullusmagnus (and Dandrake for finding a good structure to use)! Nanobug 02:46, 15 Oct 2003 (UTC)
Ditto! Cyan 03:02, 15 Oct 2003 (UTC)



Glad the Quine categories helped, but all credit for organizing the list goes to Paullusmagnus. I put in the Quine material because I thought it would be relevant, without thinking about using it to modify the list. This will remind me to be more diligent about reading the Talk pages before making changes. Meantime, organizing them this way made a real improvement.

However. When one organizes the entries rather than leaving their veridicality as an exercise for the reader, one will hit controversy. In this case I contend that the Monty Hell problem is falsidical, or at best an antinomy that's nearly two centuries out of date. The article now shows why this is, with an explanation that compensates for poor organization by running to excessive length.

In brief, we have here an argument that a function M(t), the money in the account, is non-zero at some point and increases monotonically, but is zero "at infinity". Not only monotonic, but strict. Not only increasing, but increasing without limit. Something is wrong, no?

Followups to Talk:Monty Hell problem. Dandrake 19:46, 15 Oct 2003 (UTC)


This article links to an article ethical paradox which it claims exists, but which apparently does not. ADMINS: was there ever such an article? Or is this a practical joke in this article?

Pakaran 19:51, 18 Oct 2003 (UTC)

It's probably just pre-emtive, waiting for someone to write the article. :-) Evercat 19:55, 18 Oct 2003 (UTC)
Ok thanks. Then there was no such article? Pakaran 19:59, 18 Oct 2003 (UTC)
Apparently not. There's no indication that it ever existed (and was deleted). Evercat 20:01, 18 Oct 2003 (UTC)
Ok thanks. I'm watching this article, and will write the ethical paradox article when I gather a few examples :) Pakaran 20:06, 18 Oct 2003 (UTC)

***** comment and question

01/14/04

The first line of this article is:

A paradox is an apparently true statement that seems to lead to a logical self-contradiction, or to a situation that contradicts common intuition


Why is a paradox "apparently true"? I intend to edit that first line to read "A paradox is a statement for which distinct, apparently valid modes of analysis lead to conflicting conclusions" unless there is some objection. Any better ideas?

***** end of comment

That is a MUCH MUCH better definition. Change it asap.


Here's a paradox that's bothered me ever since (believe it or not) I was eight years old:

Did time have a beginning?

If it did, then there must have been a moment before which there was no before. This is a paradox.

If it did not then the past is infinite, going back and back and back and never beginning at all. I'm not sure if that constitutes a paradox, but it makes my head spin.

Kant considers this in the (first) Critique, at B454 and following.

Comments? Lee M 04:29, 24 Jan 2004 (UTC)

From what I know, no one is really sure what time is, on a fundamental level. It's entirely possible that people's ways of thinking about and understanding time do not correspond to whatever feature of the universe it is that gives rise to the experience of time passing. Einstein's special relativity changed the way people thought about simultaneity; Stephen Hawking, if I recall correctly, once proposed that by treating time as an imaginary variable, one could formulate a model of the universe which was finite, but closed in such a fashion that there was no point at which time could be considered to have started. -- Cyan 06:07, 24 Jan 2004 (UTC)

In my opinion, the solution to the paradox is that time doesn't exist in reality. It is a virtual construct created by our consciousness to have an idea about "past" and "future". In this solution, in reality there is only the "moment" which is changing. Since our consciousness can observe our surroundings and *save* our observations(memory) and make *predictions* about what will happen next, we created the idea of time, to describe what is saved in our memory(past) and what we expect to happen next(future). Thus, the beginning of "our time" is our birth. Time requires memory - the universe does not need memory to save what happened - it gets encoded directly into the "moment", simply by actions leaving traces - by Lyx --82.141.52.54 00:08, 24 May 2006 (UTC)

Well here's a question that certainly makes time a paradox in my eyes. (And believe it or not, but my revelation was at about eight too.) If time spans ever and ever backwards, and will span ever and ever forwards, why are we at our present time? And if time does have a finite begining and an infinite end, why has it not passed our current time allready? I might not believe in time, but even I must wonder about that. --Hakusa - Wiki addict: 20:15, 27 July 2006 (UTC)

Isn't Schrödinger's cat a scientific paradox? KRS 14:00, 9 Feb 2004 (UTC)

I believe that it's just an analogy to point out what's absurd about what goes on at the particle level. As soon as a particle is observed (interacts with anything else), it's wave function collapses, so the entire cat (or any collection of interacting particles) must have a real state. Paullusmagnus 23:15, 9 Feb 2004 (UTC)



Is Catch-22 an example of one of these types of paradoxes? Essentially, "to get out of the army, you have to be crazy. But if you want to get out of the army, you're clearly sane." The wiki entry on catch-22 refers to it as "circular logic," but doesn't that qualify under one or more of these categories? Elf 03:05, 10 Feb 2004 (UTC)


<Copied from user talk pages>

You <Paullusmagnus, that is> wrote:

"St. Petersburg isn't a paradox at all -- you have to assume that utility is proportional to quantity."

I thought so too, until I read the external link at the bottom of the St. Petersburg paradox page. It turns out that you can reformulate the problem by paying off in "utiles" (the unit for measuring utility) instead of dollars, so that the structure of the paradox remains unchanged (i.e. infinite expected payoff but unwillingness to make the bet). -- Cyan 22:23, 25 Feb 2004 (UTC)

That'll teach me to think that I understand a paradox. The external link is a great explanation, and I'm partial to the "utility limit" theory, myself. Seeing as the solution depends on what exactly "utility" is, do you think we should move it to the "Conditional paradoxes" section? Paullusmagnus 18:32, 26 Feb 2004 (UTC)

<end of copied text>

Sounds good to me. I'll do it. -- Cyan 18:44, 26 Feb 2004 (UTC)

Does this need to be locked? Pakaran. 02:57, 18 Mar 2004 (UTC)


OK, it seems we have an edit war over the jaw-droppingly trivial issue of whether the line "Paradoxx is a hard rock band" should be included at the end of the article. What I'd like to know is why anybody thinks this is an issue worth edit warring over? --Camembert


Why? Because the two warriors are engaged in continuous edit wars wherever the possibility presents itself. (It may well be argued that one of them is more to blame than the other, but this is not the place for setting the record straight on the matter.) Edit wars involving these two and wars involving one of them and some other person have occupied an unconscionable amount of Wikipedians' time for a few weeks, but the new conflict resolution procedures have not yet had the power to stop the nonsense. (Or had not, as of yesterday.) Sit back and wait; an improvement is likely soon; and be glad that this page is one of the minor victims of the wars. Dandrake 03:46, Mar 18, 2004 (UTC)

Yes, I'm well aware of the history (I'm on the arbitration committee). I was hoping for an answer from the involved parties themselves. On the one hand, Paradoxx being mentioned at the bottom of the page is quite unobtrusive; on the other, Paradoxx are a tremendously obscure band, and the chances of somebody looking for them and making this spelling mistake are probably very slim. So I was wondering why this was a matter of such burning importance that they have to edit war over it. --Camembert

Edit warriors get into edit wars as a matter of principle. The obscurity of the issue has nothing to do with it. -- Arvindn 07:54, 18 Mar 2004 (UTC)

I'm really hoping for a reply from the involved parties. --Camembert

Perhaps you should leave a message for them on their respective talk pages. -- Cyan 19:45, 18 Mar 2004 (UTC)

Ethical paradox

Shouldn't the ethical paradox be, "Love thy enemy" rather than, "Love thy neighbour"? I think it would clear things up as neighbours don't, on the whole, kill each other, and, "Love thy enemy" is the Christian commanmant.--[[User:HamYoyo|Bendž |Ť]] 09:45, Jul 15, 2004 (UTC)

new pic

I like the new pic lots better, hoorah! Sam [Spade] 17:43, 15 Jul 2004 (UTC)

Perpetual motion machine

Is a ppm a good example of a paradox? It's just bad physics, there is nothing really paradoxical about it. Mark Richards 23:54, 15 Jul 2004 (UTC)

Most paradoxes are just bad math, so I'm not sure how certain ppms are so different. anthony (see warning)

Quine

Quine did distinguish three classes of paradox. If his distinction has been questioned, someone might insert a reference to the problem. Meanwhile, what on earth is gained by the weasel-wording of saying he believed in them, as if they were Santa Claus? It looks to me like a misguided attempt to follow the guidelines about sneaking in assertions as if they were facts, with phrases like "noted that"; but it's not such an assertion. If someone else made a different distinction, and it's any good, we ought to hear about it.

We may want, though to restructure the entire article, which is organized around this distinction.

I changed the footnote style to one that's widely used in scientific work. There's no standard at Wikipedia, but numeric footnotes are a really hopeless idea in a work that's subjcet to eternal revision and has no mechanism for automatic renumbering. Let's go to numeric footnotes when we chagne the Wikipedia format to LaTeX! Dandrake 19:02, Jul 16, 2004 (UTC)

How is this called?

1. All the sentences in this box are false.
2. Nothing Else Matters is the best ballad ever.

Sentence 1 can't be true, because it would imply itself to be false, which is a contraddiction. So it must be false.

If Sentence 2 were false, both sentences would be false, but this is not possible, because Sentence 1 would be true, which would be a contraddiction.

So the only possible truth values are FALSE - TRUE. Sentence 2 is true, and Nothing Else Matters is the best ballad ever, Q.E.D.

You could use this to prove anything, including obviously absurd sentences such as "I don't exist" or "4 is a prime number". You just need to replace Sentence 2 with anything.

I don't know how this is called, so I would not know how to title an article about it. If you know its name, create a new article with the appropriate title and move it there.

Well, it's equivalent to a simple variation on Curry's paradox. But it's also equivalent to simple variations on the liar paradox, and to stuff Russelll toyed with at the turn of the century. But it's a mug's game to generate new ones, so I very much doubt that the Nothing Else Matters version has a name. Call it the Hetfield paradox, maybe. Inceidentally, exactly that paradoxical proof method was used by Raymond Smullyan in What is the Name of This Book?, but I doubt he was the first.
Did it have a name, in that book?
Would you believe, "What is the name of this paradox?

However, now I remember where I found that. There was a version of unexp. hanging paradox where Alice and Bob (the names weren't this ones but I don't remember them) make a bet: there are ten numbered boxes, Alice puts an egg in one box, then she bets that when she opens the boxes, in order, Bob won't be able to expect to see the egg. Bob thinks "it can't be in the 10th box, else when the first 9 boxes are opened I'll be able to expect to see it in the 10th. Therefore, it'll be in a box from 1 to 9. it can't be in the 9th box, else when the first 8 boxes are opened I'll be able to expect to see it in the 9th. Therefore, it'll be in a box from 1 to 9. etc." and gets confused. Alice opens the box, the 5th box contains the egg, Bob couldn't expect that, and Alice wins. Somebody (jokingly, i hope) answered that Bob could expect that because... (and draws a box like the above where the 2nd statement was "Alice's egg was in the 5th box"), and therefore he should win the bet. --Army1987 15:48, 19 July 2005 (UTC)


Actually I just chose a random sentence. I read about that paradox somewhere, but I don't remember what sentence was used. --Army1987 21:52, 21 Jun 2005 (UTC)
Now I read Löb's paradox again, and the one I cited seems the same thing...--Army1987 17:17, 3 September 2005 (UTC)

All that would prove is that you cant trust people who put statements into boxes. In fact the second statement is an opinion and not really subject to truth or falsity. - flurbius

Removed from page

The following text was removed:

Dollyknot's Paradox: A paradox is something that contradicts itself - therefore it is not a paradox.

The term "Dollyknot's Paradox" has zero Google hits except on this page, so this looks like an idiosyncratic term created here. Unless, of course, someone can provide evidence that this is a known paradox? -- The Anome 14:16, Nov 8, 2004 (UTC)

"Dollyknot's Paradox"

"Dollyknot's Paradox" doesn't, I'm afraid, make sense anyway. First, a paradox doesn't necessarily contradict itself; as the main article makes clear, many of the most famous and argued-over paradoxes contradict commonly held beliefs (as, for example, most of Zeno's paradoxes, the Twins paradox, etc.). Secondly, even if paradoxes were all self-contradictory, the consequent – "therefore it is not a paradox" – is a non sequitur.


I've re-organized the categories. As they stood there were at least two problems with them. (1) Sorting paradoxes into the veridical/falsidical lists presupposes determinate solutions which almost none of those have. Some of the other category headings and descriptions, such as conditional paradoxes, likewise made a number of claims about the paradoxes that were highly contentious. (E.g.: A great number of philosophers working today don't think that the problem of Theseus' ship is a problem of definition. They think it's a real (and deep) metaphysical problem. Sure, they're a lot of fools, but who is wikipedia to say so? Ditto the Sorites paradox, and a heap of others. It's not even widely agreed where the problem lies in many of the paradoxes that had already been sorted for "truth value". (2) The previous categories reflected (at least) two classification systems working at odds with one another. Some paradoxes were sorted by subject matter, others by veridicality. Imagine is I sorted sentences into four groups: (a) true ones (b) false ones (c) Those about mathematics and (d) Those that involve presuppositions. You can see the problem? Barring massive repetition on this page, it seems to me the simplest thing to do is to sort the paradoxes thematically, and leave all questions as to why they are paradoxes, and how to resolve them, to be discussed on the page for each individual paradox.


The "paradox of denial" seems to me to be more a play on words than a paradox. Two different connotations of the word "accept" are being used. First it asks how can one accept ("be satisfied with") oneself if one is unhappy with oneself. Then it asks how can one change if one does not accept ("have a realistic image") of oneself. I think many, many paradoxes could be generated along these lines. Is this some kind of joke? Who proposed this as a paradox?

Formatting problem

In Firefox, some text goes over the 'listen' box, in IE some goes underneath. Fix, please - I would, but I donae have a clue how to. --210.246.30.209 04:00, 19 July 2005 (UTC)

Explain something. Somebody. Please

It would be a good idea that the Friederic´s age paradox was explained somewhere as having to read the play to konw what the article is refering to is obviously not a good idea. Somebody added it in [this] edit and nobody ever modified it as if it were perfectly explained (and this is a featured article).


Paradox classification problem, possible significant error

Russell's paradox is listed under semantic paradoxes rather than under logical ones. However, I have a set theory textbook, author Charles C. Pinter of Bucknell University, which says, "The paradoxes of set theory are of two different kinds, the one called logical paradoxes, the other called semantic paradoxes . . . The simplest of the logical paradoxes is Russell's paradox, which can be described as follows: . . . " The author of this textbook disagrees with Wikipedia that Russell's paradox is a semantic paradox. JDF, Oct. 12, 2005

It seems more likely that Rusell´s paradox is a logical one. It has noothing to do with meaning.

I hope that someone can clarify this for sure, based on current interpretations, and perhaps list the paradox under logical ones for now. Ironically, I have a paper to a set theory journal currently that makes a case for the paradox as semantical, which is why this matter interests me. If it is already considered semantical, the paper has a problem. JDF, Oct. 13, 2005.

I moved the paradox into the logical category because the textbook cited above says it is a logical paradox, and W. V. Quine said that the parallel between the barber paradox and Russell's paradox "is exact," and the barber paradox is a logical paradox. JDF, Oct. 13, 2005.

Should remove Jevons Paradox

Jevons paradox is a paradox only in name. Does economic literature treat it as an actual paradox? If not, then it should be removed. --Flatline 18:41, 19 October 2005 (UTC)

Monty Hall problem is not paradox

There is absolutely nothing paradox in the Monty Hall problem. You cannot call something "paradox" only because a lot of people do not understand mathematics. There is no logical contradiction here. --129.69.45.44 11:07, 6 December 2005 (UTC)

You most certainly can. According to the article "a paradox is an apparently true statement or group of statements that seems to lead to a contradiction or to a situation that defies intuition". -Dan 14:35, 6 December 2005 (UTC)
It does neither lead to a mathematical contradiction nor defy intuition. The latter is btw a very subjective point, I find the solution of the MH problem very intuitive, other people might not. But why should a mathematical problem be intuitive? Do you look at some calculus problem and think that you should understand it intuitively? Where do people get the conviction that they should be able to understand the Monty Hall problem "intuitively"? A problem like this does not lie in the realm of "common sense", it's mathematics; so please use the definition concerning "logical contradiction", and there is no contradiction. --129.69.45.44 14:43, 12 December 2005 (UTC)
Another example: mathematics tells me that (a+b)^2 = a^2 + 2 a b + b^2, but common intuition says that it should be a^2 + b^2 (according to my experiences from giving private lessons). Would you call this a paradoxon? --129.69.45.44 14:56, 12 December 2005 (UTC)
Come now, of course it lies in the realm of common sense. Do you need to know algebra or calculus to play Let's Make a Deal? But if you insist upon it, most of the paradoxes on this page will not meet the "logical contradiction" definition. -Dan 16:27, 12 December 2005 (UTC)
Not for playing, but for calculationg the chance of winning... --129.69.45.44 12:38, 13 December 2005 (UTC)

Please also include the following paradox in the list:

Maybe you should consider listing only true paradoxes, instead of lots of puzzles that some people just do not understand. --129.69.45.44 12:47, 13 December 2005 (UTC)

Or you could consider it. Your edits singled out Monty Hall for no good reason, and I stand by my decision to revert. As for a general classification into proper/improper paradoxes, you could read the entire article, and also the entire discussion page above. Then, "if you see a way this page can be updated or improved without compromising previous work, please feel free to contribute", like the sign says. -Dan 15:27, 13 December 2005 (UTC)

Read Marilyn vos Savant for an idea of how many people, mathematicians among them, were completely certain of the wrong answer to the Monty Hall Problem.

CHALLENGE - I will solve any paradox or...

My contention is that there is no such thing as a real paradox. I am including those that can be phrased verbally, proposed scientifically or mathematically.

I propose that I will either:

  • Provide a solution that can be proved through math and or basic principles of logic (including identifying erroneous and/or implicit assertions).
  • Identify the unknown quantity, variable, or assertion that cannot be currently verified as true or false. (which of course disqualifies a puzzle as a paradox).

I would suggest to the reader and student that a paradox is simply an unfinished or incorrectly presented mathematical or logical proof.

The classic example is:

"This statement is false." seems to be an example of a paradox. The misunderstanding is simply an implicit assertion that all statements contain, that assertion being "This statement is true". When taking into the implicit assertion the statement becomes "This statement is true and this statement is false." A. N. Prior is credited with the solution to this example.

But that solution is not generally accepted, is it. -Dan 04:36, 19 December 2005 (UTC)
It's true that you can prove that one statement in a contradiction is false. On the other hand, an apparent contradiction is no contradiction at all, only a contradiction on first sight. On subsequent inquiry it proves not to be contradictory, but just involving something we didn't know or think about at the time. We are so used to seeing the word paradox used incorrectly, that there is an apparent contradiction when we see it used correctly. I think we have witnessed a paradox when we concluded that there wasn't one and that paradox is a non word, if you see what I mean.
"The misunderstanding is simply an implicit assertion that all statements contain, that assertion being "This statement is true." would be a guess at the veracity of a statement and a contradiction of the truth, if I have put that clearly and it makes sense to anyone. I might as well say also that an intuition is the sense that something doesn't go along with reality as directly experienced, our sense that most directly experience reality and empirical or informed intuitions. It's informed through knowledge and experience, as Einstein clearly says. In other words it is not good to think something that makes sense, makes no sense, or common sense, a contradiction in terms. Common sense is supposed to mean the sense common to us all to see through irrational thoughts. Common nonsense or belief is an entirely different thing.
Of course I entirely agree with you that there are no contradictions, but only errors in our thinking or paradoxes caused by the limited knowledge of the average person, not just the experts, who may know the difference or not. I rather think that what we don't know is infinite or more, leaving us knowing relatively nothing, at least not completely and that can make a critical difference.
An intuition identifies something that goes against the much larger database of the whole mind and all experience and even against our very physical being, body chemistry, cell operation, etc. It's the basic sense that keeps us out or trouble or is used in "comfort zone navigation" at sea.
I'm sure that goes against common notions about the word, but, if we do the research, we should find that it's true and that the greatest minds ever, many philosophers, like Kant and Aristotle and perhaps especially top mathematicians, all agree. For mathematicians see Poincare, Evariste Galois, Felix Klein, Blaise Pascal, Pierre Gassendi, Philosopher, Mathematician Descartes and so forth. It's not an something exotic, but just the various types of calculations and languages that the brain can use automatically, as hard science is now verifying.
Also I see counterintuitive as an oxymoron. If you don't know something or it hasn't been tested, then the intuition can be confounded, but if you intuition tells you it hasn't been verified or is not in you database of experiences, conscious or subconscious, it so notes. You can't counter not knowing, because it is true that you don't know, unless there is something I don't know about that. The phrase has just become popular among many people who can't identify their intuition and don't know that we have it as a normal brain function that we need, as it specifically deals with complexities, like those of the information age. It's weak on math and irrational thoughts. It can identify them through emotions, but we are "the decider". Cognitive Psychology and the Neuroscience of emotions.
I will defer to those more knowledgeable and courageous than myself to make any changes. Thank you for any consideration of these issues. Hrld11 (talk) 12:34, 18 May 2010 (UTC)
I would suggest that the solution has not met general acceptance because the solution has not been as widely distributed or as easily understood as the paradox is. Acceptance is not required for a solution to be correct; if the solution is correct then it will be accepted one day. If you can demonstrate to me why the solution is incorrect, then we can put forth the correct solution, or identify that which is unknown or assertion that cannot be verified. With a simple paradox such as this, I do not think that we will find that there is an unknown quantity or undefined assertion. I suggest that it is the simplicity of this paradox that not only makes it challenging to consider, but should also makes it rather elementary to solve.
That's not really the way the "This sentence is false." paradox works. If it is true, then it is false. If it is false, then it is true. It is not assumed beforehand that the sentence is true. -Seth Mahoney 00:48, 20 December 2005 (UTC)
Let me suggest that you consider for a moment that your belief that "it does not work that way" may simply be a difficulty to perceive the implicit assertion in the statement. The implicit assertion I refer to is the implicit assertion all statements have, the assertion that "this statement is true".
For example "Two plus two equals four." is the same as the statement "Two plus two equals four and this statement is true. Both statements evaluate to "True". However, if I say state: "Two plus two equals five." or "Two plus two equals five and this statement is true." Both statements evaluate to false.
Consider statement or proposition p An identity law of logic states that: (p and NOT p) evaluates to FALSE
Again, I propose to you that there is no such thing as a paradox.


I counterpropose that the reason it's not generally accepted is not due to ignorance. How could you justify that "This sentence is true", by itself, is true? Also, what about:
  1. Statement 3 is false.
  2. Statement 3 is false.
  3. Statement 1 is true.
  4. Statement 1 is true.
Which of these are true? -Dan 21:31, 21 December 2005 (UTC)
Clever, but "This sentence is true." simply leads to the statement "This sentence is true and this sentence is true." While redundant, it is a valid english statement. The idempotent law of logic states that: (p and p) evaluates to p. I submit that a statement asserting its own truth is not a construct of society (well not anymore than any other type of math or logic), but logically certain and mathematically required.
As for the paradox involving the 4 statements, this is an especially clever version that seems to address the solution. But consider for a moment the fact that the information each statement provides relies on each other statement. What we then have is a compound statement that has simply been broken down into separate statements using the semantics of the english language. What this means is that there is a single assertion of truth for the entire compound statment. Further I would suggest that you have not made four statements, but merely inferred an implicit assertion: "There exists a semantic tool in the english language that models a mathematical/logical loop for which the exit is undefined." This implicit assertion would appear to be true. An undefined quantity is not a paradox and is often used in mathematical structures such as limits and asymptotic behavior.
I'm not sure what you're saying here, is this some sort of asymptotic truth value? It sounds like it is a long way from Prior's answer. Are you sure he would agree with it? -Dan 15:59, 22 December 2005 (UTC)
  • I only mentioned the an asymptote as an example of the use of an undefined value in mathematics. Perhaps I should have restricted my example to the limit as it is a more general structure.
  • No.
So each individual sentence is undefined in a sense, but their conjunction is true due to the implicit assertion that (roughly) "there is a loop with no exit"? First, this is not implicit in the four sentences. They say nothing about there being an exit or not. I may have asserted (by saying "I counterpropose...") that the one particular solution was not an exit. Second, this would seem to require "S1 and S2 and S3 and S4" taking on a truth value (true in this case) which is not determined solely by the truth values of S1, S2, S3, and S4 (all undefined in this case). -Dan 17:47, 23 December 2005 (UTC)
The four statements you have listed above do not exist as individual statements. If they do not exist as individual statements that means we have not defined individual statements. That which is not defined is undefined by definition. However clearly four statements exist and are defined in context of each other's existence. In mathematics we can model a situation using a construct called a limit to handle situations that are undefined to measure that which is otherwise difficult to measure...such as changes in motion. This analogy is rather abstract, so allow me to illustrate an simpler exampler. We could have as easily stated in English "This circle goes around and around and around..." You get the idea no end to the statement, but the same statement. Not very useful in and of itself...just a simple loop. We know that we can, in math, construct a loop without an end or exit. Perhaps it is not so difficult to do this in English as well. To come full circle (bad pun intended), we use undefined quantities in science everyday and do not consider them to be paradoxical in nature at all. As for the assertion "they say nothing about there being an exit or not.", I put forth that you are mistaken in this assertion, and that they do "say", albeit implicity and by means of implication, (imply) the existence of semantic loop structures.

Forking List

I've just demoted this article, and while looking at it I saw that this article is essentially a mega-stub with a rather long list at the bottom. I have forked the list into its own article, and refactored the existing article a bit. This is where we can get a fresh start and expand this article to potential featured status again. BE BOLD!!! --Jeffrey O. Gustafson - Shazaam! - <*> 02:39, 31 December 2005 (UTC)

What purpose is served by putting the list into a separate article? It there's something wrong with its content, you are not making the Wikipedia as a whole any better by just moving it. Also, why is a "fresh start" needed? And why is removing the list of paradoxes necessary for getting a fresh start. This article will always have a long list of references to other articles. That is because there are a lot of paradoxes (under different senses of that word) and many of them have articles. --Nate Ladd 03:55, 1 January 2006 (UTC)
This article used to be featured - part of the reasoning for its deserved removal this week was that it is mostly a list, which is accurate. Keeping that in mind, I forked the list, which gives a potential article in the making breathing room. There is a reason why we have "List" articles here, so as not to bog down the articles themselves - long lists have no place in articles. Imagine, for instance, if you put the List of TV shows at the end of TV show... as you said, there are a lot of paradoxes, so the fork is entirely called for, and has more than enough precedence. --Jeffrey O. Gustafson - Shazaam! - <*> 10:17, 4 January 2006 (UTC)

While I approve of moving the list to a separate article, the reult is now that the main article on paradoxes doesn't actually state an example of a paradox. I'll add a couple well-known ones. Captain Wacky 04:28, 20 February 2006 (UTC)

Robert Boyle

Is the self filling glass really a paradox? The Glass itself is possable but in order to get a paradox one is forced to assume that the water defies the laws of gravity. JedG 10:49 January 7th (PST)

Paradox etymology

"The etymology of paradox can be traced back to the early Renaissance. Early forms of the word appeared in the late Latin paradoxum and the related Greek παράδοξος paradoxos meaning 'contrary to expectation', 'incredible'. The word is composed of the preposition para which means "against" conjoined to the noun stem doxa, meaning "belief". Compare orthodox (literally, "straight teaching") and heterodox (literally, "different teaching"). The liar paradox and other paradoxes were studied in medieval times under the heading insolubilia."


Just a clarification/addition. The fist use of the word 'paradoxo' is traced back to the greek philosoph Zeno of Elea, who lived at 490-430BC. It was used to describe a philosophic idea of Zeno, knonw as Zeno's paradox. Later on it was pick up as 'paradoxum' in the Latin language, when greece was part the roman empire.

Some more sources: http://www.iep.utm.edu/z/zenoelea.htm http://plato.stanford.edu/entries/paradox-zeno/

Excellent pick-up, and really fascinating. I'll implement your information to the etymology section immediately. --Piewalker 18:24, 17 January 2006 (UTC)

Can a question be a paradox?

I was thinking today about this yes-no question: "Is the answer to this question 'no'?" There seems to be no true answer to it. Does this qualify it as a paradox?

It's not a paradox. I can say "it could have been."
(unsigned).
This sentence is a lie.
Whether the sentence is a paradox in itself, or whether one needs to make some statements about the nonsense one may so easily get oneself into when discussing the sentence before it can properly be called a paradox, I don't know, and I don't care. But the Liar paradox is certainly a paradox revolving around a sentence that is confusing in a way very similar to the sentence
Is the answer to this question 'no'?
--Niels Ø 14:48, 26 March 2006 (UTC)

Question

Do paradoxi(is that the plural?) exist because the human system of logic is essentially flawed, or because thinkers are yet to come up with logical answers for each paradox? Thanks, --Urthogie 13:46, 26 March 2006 (UTC)

The human system of logic is not flawed, but some paradoxes teach us about limits in its applicability, some paradoxes teach us that the seemingly sound premises involved in a logical argument are in fact flawed, and yet others teach us the meticulous care sometimes needed in order to apply the system of logic correctly, in order to avoid e.g. equivocation.--Niels Ø 14:52, 26 March 2006 (UTC)
What exactly are the limits of human logic?--Urthogie 14:57, 26 March 2006 (UTC)
Logic is not about the world; it is about ways of combining statements. As such, it is infallible. Logic is hard as rock, and as limitless as pure mathematics - and as limited. Applied to concepts with loosely defined meanings, nonsense may easily result. Essentially, that's what I meant by equivocation above. Also, applied to statements that are only 99% true, you may get funny results:
All humans are living organisms.
Nearly all living organisms are micro-organisms.
Hence, nearly all humans are micro-organisms.
--Niels Ø 20:30, 26 March 2006 (UTC)

Ok, so basically you're saying that the limitations of logic and mathematics result from the fact that all concrete thought relies on language-- and all the limits are in the language? That would make sense, if that's what you're saying.

Also, those three sentances are not a paradox. The logical fallacy is in getting from step 2 to step 3. For The transition from 2 to 3 to be logically sound, step 2 would have to be: "Neraly all living organisms are nearly all micro-organisms."--Urthogie 06:49, 27 March 2006 (UTC)

Yes that's what I'm saying. The three sentences - the point of the example is, if you apply logic to statements that are nearly true, you may reach conclusions that are utterly untrue. E.g.,
All humans are living organisms. (True)
All living organisms are micro-organisms. (Well, nearly true...)
Hence, all humans are micro-organisms. (Not true!)
But I'd like to have a better example...--Niels Ø 18:17, 27 March 2006 (UTC)
Ah I see what you were saying, and the example makes more sense now. Would you agree with my statement, however, that "the limitations of logic and mathematics result from the fact that all concrete thought relies on language-- and all the limits are in the language?"--Urthogie 19:03, 27 March 2006 (UTC)
Yes I agree.--Niels Ø 22:32, 5 April 2006 (UTC)

Koan

Would Zen Koans not deserve a mention under paradox? (added 21:07, 5 April 2006 by user:84.9.151.133

If someone can write a suitable brief paragraph on koans, I'd love to see that in the article.--Niels Ø 22:29, 5 April 2006 (UTC)

Alteration one million and six

A contradiction can be true, I think he meant 'an instantaneous self contradicion'... someting that couldn't exist because of itself. The concept exists, just not the thing itself. It's like a word that can't be broken. I have put (somehting like) a defintion at the top and will leave the rest for an editor with a rainy day and some aspirin.

"A Paradox is the concept of self contradiction inherent in the concept itself. A true paradox cannot exist by definition."

86.135.97.90 05:21, 11 April 2006 (UTC)

Paradox as Product of Unthinking Intuition

Added remarks on social need to resolve paradoxes to stop crimes based on false paradoxes, on relation between paradox and illusion, and on how to resolve paradoxes by defeating intuition and using causal analysis in its place.

Inserted additional wiki links and externallinks. Gani 21:33, 23 April 2006 (UTC)

This whole section seems to be rather POV??? I mean, that there is a clear agenda evident in the sections "Intuition is the Biggest Enemy of Social Science" and "How to Defeat Intuition and Resolve Paradoxes". An encyclopedia article is not the place to present a method that can be used to "defeat" something, or at least with connotations that the thing which is to be defeated unconditionally deserves it. The whole section comes off like a manifesto for some insecure victim of charlatanry or staunch advocate of empiricism---its just badly written. 72.60.88.172 03:20, 24 April 2006 (UTC)

"Intuition is the Biggest Enemy of Social Science"

This section should definitely be removed. It's vague, very POV, and unsourced.

I agree that the "paradox is the result of false intuition and enemy of social science section should be removed. It completely contradicts the rest of the spirit of the article, and the spirit of an encyclopedic article. If anything it should be placed under "anti-intuitionism".

Okay. So, I removed:
The stated 'factually true' outcome defies intuition, just because intuition is 
unable to formcorrect expectation as it ingores pertinent causal factors. 
Philosophical and mathematical paradoxes may seem to involve contradiction.

and

Social sciences are particularly victims of unthinking intuition giving rise to 
paradoxes. They can achieve great advances by resolving the paradoxes through careful 
causal analysis. It is very important to bust the paradoxes and the falsehoods based 
on unthinking intuition, because great many crimes against humanity are committed 
according to false theories created by thoughtless intuition. This includes crimes 
against humanity based on the Paradox of Fertility to impose forcible 
sterilization or coercive birth control, the Paradox of Slum Preference to deny 
desperate rural paupers a chance to survive in the cities, and the 
Paradox of Poverty which prevents the reform of monetary systems to permanently 
solve needless poverty by enabling employment of productive people who are unemployed 
because of perversions in monetary systems.
==Paradox versus Illusion ==

A paradox in social science is akin to illusion in natural science. An illusion occurs 
as a result of faults of observation owing to faulty sensory organs. In an illusion, 
reality appears to be other than what it is. For example, when an airplane flies away, 
the observer sees that it is becoming smaller and smaller and ultimately it vanishes 
from view. But the observer also knows that the plane is actually not becoming smaller 
at all. There are great many examples of optical illusion where things seem to be other 
than what they really are.
Every sensory organ is liable to misperception or illusion. Just as our eyes fail to 
see extremely distant or extremely tiny objects, our ears fail to hear sounds that are 
above or below a certain range of audibility. In short, we hear only a fraction of the 
sound around us, and do not hear the other sounds. Our senses of smell and touch are 
also limited, meaning that we fail to detect many smells or feel many kinds of touches. 
Our tongues are also unable to taste things unerringly, as they tend to get confused by 
mixtures of substances.

Natural sciences have devised various instruments of observation to overcome the 
failure of sensory organs. Thus telescopes can see distant objects that our naked eyes 
fail to see; and microscopes can see tiny objects that our naked eyes cannot see. 
Likewise, there are instruments of observation to overcome the failure of other sense 
organs.

Paradox is a different kind of illusion in that it does not relate directly to 
observation, but to the causal meaning of observation. Just as a naked eye is not 
equipped to correctly detect the presence of microorganisms, the untrained mind or 
naked mind (usually called intuition) is not equipped to assign a correct causal 
meaning to events. In other words, an intuition is the illusion of the unthinking 
mind, and it creates a paradox.
For example,the diamond-water paradox arises before the unthinking mind as it creates 
a causally wrong prediction or expectation about relative price: it wrongly expects 
prices to be proportional to usefulness. In reality, price depends on both demand 
factors (such as relative usefulness or marginal utility) and supply factors (such as 
relative scarcity or marginal opportunity cost). The high price of diamond relative 
to water should not have been unexpected in the first place so that the sense of 
paradox would not arise at all.
If we stubbornly insist on using our naked eyes, we are bound to get wrong ideas about 
microorganisms, namely the wrong idea that they do not exist at all. Likewise, if we 
insist on intuition, we are bound to reach wrong conclusions about causal relations 
in social spheres. Intuition prevents us from understanding the complex social events, 
because it ignores pertinent factors and thereby promotes ignorance.
==Intuition is the Biggest Enemy of Social Science==

Intuition is indeed the biggest enemy of scientific understanding of social realities. 
We understand social realities in terms of human motives. Intuition supplies an 
uncritical motivational link to an event in which human action has some relevance. In 
the diamond-water paradox, the intuition is uncritical, and assigns the human motive 
to paying price such that the price is proportional to the relative usefulness of the 
object. This motivational premise is false, and it is the result of lazy minds 
refusing to consider relevant factors.
The uncritical mind thinks that reasonable humans would not pay a high price for 
something of low usefulness. This intuition is of course false, because people do pay 
high prices for things presumed to be of little usefulness. But the explanation 
requires a more thorough analysis of many pertinent factors, such as the marginal 
utility and the marginal cost of production.
The treachery of intuition has very adversely harmed humanity, especially with respect 
to economic matters. Almost all economic events are paradoxical: they are beyond the 
grasp of unthinking intuition. However, great many authors and speakers promote what 
is called an intuitive approach, which is like the promoting superstition and 
quackery. We are indeed deluged with cheap shots of unthinking charlatans. They appeal 
to us because we refuse to think and readily swallow false statements just because the 
sound credible or plausible.
Natural sciences are about material phenomena, and those sciences fight against 
illusion by using instruments of observation. Social sciences must also fight against 
intuition by pursuing causal analysis. The problem is not the facts as such (unlike 
in natural science), but what the facts mean. Economists rarely disagree over the 
facts, but they vociferously debate what the facts mean. In this battle, the usual 
winner is the enemy of science: the ever beguiling intuition, the favorite of the lazy 
thinkers who refuse to think but lazily rely on unthinking minds.
Intuition is the mother of all superstitions. It is also the only reason people fall 
prey to cheats. The fraud presents arguments that seem credible only because the 
victim does not bother to check the purported fact or in most cases the presumed logic. 
If something sounds credible, it is not necessarily so until a serious scrutiny 
establishes that it is so. The first part of the scrutiny is to falsify it, or try to 
say that the purported fact is not true or the logic is not valid. The second part is 
to confirm the facts by careful observation.
Humanity at large is being cheated on grand scale by purveyors of all kinds of 
superstitious and fraudulent claims. The only recourse is to wake up the minds, equip 
them with critical ability and defeat intuition (and the products of intuition, which 
are superstition, fraud, and falsehood).
==How to Defeat Intuition and Resolve Paradoxes?==
To defeat intuition, one must begin with the dogmatic stance that ‘if it is intuitive, 
it is false’. This is not meant to be a statement about truth, but the statement of 
an attitude of skepticism. It is a call to deploy analysis. The skeptic should try to 
contradict and refute any statement that relies on intuition. To contradict is to try 
to present an opposite meaning. To refute is to present contrary factual evidence 
and/or logical argument. But to contradict and refute is to think, and that is indeed 
the medicine for the unthinking mind: force it to think.

I may have been too cut-happy, but my intuition told me to cut out the entire sermon. -Dan 02:28, 30 April 2006 (UTC)

Drinker Paradox

I created a new page about the Drinker Paradox and put a link to it here. Unfortunately that page is marked for deletion, unless we can support it by giving the source. I know that the paradox is by Raymond Smullyan, but I don't know from what book. If some of you know, please add the reference there. Also, you can join the discussion page and give your support to keep that article. Eubulide 16:23, 11 May 2006 (UTC)

The deletion request for Drinker Paradox has been withdrawn. The source of the paradox is still missing. Eubulide 21:03, 11 May 2006 (UTC)

You added this as a "situation that is merely surprising, albeit in a distinctly logical manner" which I disagree with (more on that talk page. Would it be sufficient to have this on the List of paradoxes page? -Dan 13:34, 17 May 2006 (UTC)
You must specify why you disagree. We are talking of paradoxes that are surprising because they seem to go against common sense. Also they are defined as doing it in a "logical" manner. The drinker paradox seems to be a perfect example, better that the birthday paradox that is really a statistical rather than a logical conclusion. Eubulide 13:40, 17 May 2006 (UTC)
The birthday paradox really is "merely surprising" and uncontentious. The drinker's paradox isn't. More on that talk page. -Dan 14:04, 17 May 2006 (UTC)

Paradoxography

Why does a search for paradoxography redirect here, when the article makes no mention of paradoxography as a literary genre? Is it possible to create a separate article and remove the redirect? —Preceding unsigned comment added by Cursitor (talkcontribs) 00:32, 6 June 2006 (UTC)

Probably a misunderstanding. -Dan 14:27, 6 June 2006 (UTC)

Boyle's Flask

I don't think anyone has yet adressed the question (previously asked) of why the picture we have, Boyle's Flask, is a paradox.

First of all, what does the flask do? Well, we know it supposingly provides a source of perpetual motion. According to the laws of physics, it does not.

Let's take a look again at the defenition of a paradox:

"A paradox is an apparently true statement or group of statements that leads to a contradiction or a situation which defies intuition."

Is Boyle's Flask, then, a paradox? I think the problem here becomes, what is 'intuition'? Perhaps to the physically inclined person, intuition says that perpetual motion is impossible (if there is such a person.) To the common man, there seems to be nothing wrong with the idea.

So, any thoughts? Gagueci 02:22, 21 July 2006 (UTC)

I suspect it is there for the sake of having an image. The featured article process tends to do that. 192.75.48.150 14:28, 24 July 2006 (UTC)

The picture of Boyle's flask shows perpetual motion, which is impossible. So it is paradoxical. In my opition it fits the topic of the article.

We could replace it with a picture of a real paradox. A picture by M. C. Escher would be appropriate. for example this one (Drawing Hands). [ NOTE: image was removed -- copyrighted and no fair use rational to be on this article or its talk page.DreamGuy 03:31, 16 May 2007 (UTC)]

Or we can have both. Eubulide 14:23, 26 July 2006 (UTC)

Accually that boyals flacs is a interesting example of a paradox (or at least something of that ilk), if it were captioned so:
Person A: " this can't work, the water doesn't have enough inersia to over come gravity>
Person B: "If gravity was stronger it woukld get more inersuia"
Person C: "this is true"
Person D: "but then gravity would be stonger so it couldn't escape"
Person B: "so make gravity stonger so it has more inersia.
go to start 06:15, 12 August 2006 (UTC)06:15, 12 August 2006 (UTC)06:15, 12 August 2006 (UTC)06:15, 12 August 2006 (UTC)~~

Does this sound like an existing (time) paradox?

I Somewhere in my Jr. High years I realized that if you go back in time and solve what made you come back in the first place, when the you of the past got to the point unwhich you went back in time, the you of the past would not. So essencially there would be two of you in the world. I know many might counterpoint that after the problem was solved, the future you would cease to exist, but if that were true than the problem would have never gotten solved. So, I'm guessing that this has been theorized before and I'm wondering who did it and what he/she called it. --Hakusa - Wiki addict: 20:24, 27 July 2006 (UTC)

Contradiction

It is not correct to say that a contradiction by definition cannot be true. By definition a contradiction says the opposite of what it says. In Aristotelian Logic (and many other POVs) this means that it cannot be true. In Dialethic Logic, Jainist Logic, Buddhist Logic, (and many other POVs) this means that it must be both true and false. Bmorton3 18:55, 10 August 2006 (UTC)

Are we conflating a paradox with a dialethism? Paradox is frequently used for a position that seems contradictory

Curry's Paradox unresolved (or contentiously resolved)?

"The word paradox is often used interchangeably and wrongly with contradiction; but where a contradiction by definition asserts its own opposite, many paradoxes do allow for resolution of some kind, though many remain unresolved or only contentiously resolved, such as Curry's paradox."

What about Godel's theorems? Do not they indisputably resolve Curry's paradox (if you mean that resolving is gaining a complete understanding of the cause)?

Please see: http://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems

I believe this 'resolves' any uncertainty regarding Curry's Paradox.

Actually I have no idea what you are referring to. Godel's theorems prove (1) the incompleteness of the theory of arithmetic couched in classical first-order logic and (2) that if arithmetic is consistent it cannot prove its own consistency. Curry's paradox has to do with sentences roughly of the form "if this sentence is true, then everything is true" where the consequent can effectively be replaced by anything absurd or necessarily false. I have no idea what you think these two things have to do with each other, but here is one possibility: maybe you think that the Curry sentence is an unprovable truth like the Godel sentences which are central to the proof of Godel's theorems? But that's a non-starter. If the Curry sentence is true, then everything is true. Like I said I'm not really sure what you meant by your original comment so maybe you can elaborate on the point. How do Godel's theorems bear on Curry's paradox?
-Paraconsistent (talk) 00:09, 8 August 2008 (UTC)

Time travel paradox

The artcile says:

Sometimes supernatural or science fiction themes are held to be impossible due to resultant paradoxical conditions. The theme of time travel has staged many popular paradoxes arising from the traveler interfering with the past. Suppose Rowan, who was born in 1950, travels back in time to 1901 and kills his own grandfather. It follows that neither his father nor he himself will be born; but then he would not have existed to travel back in time and kill his own grandfather; but then his grandfather would not have died and Rowan himself would have lived; etc. This is known as the grandfather paradox or as simply the time paradox

The many-worlds view bypasses this paradox. If at every event in time many worlds form to take on the different possibilities and outcomes, then there would be the "natural branching" of many worlds, and a time traveler could go back and affect the past "tree" by creating yet another branch on the tree at a lower height than what the current established height of "present" is where the myriads of braches are formed. Now this is not a nice answer, but it's one way out of a paradox, though the answer is still paradoxical because you still have to figure out what causality - the one-to-one relationshipness - means in this "anything possible" many worlds worldview - if causality stands, does creating yet another possibility branch at an earlier point erase the version in which the timetraveler is born?, or does it just add yet another version of the file without overwrites ever being possible, does it just add another world in which he does not exist? Most importantly, this many worlds worldview theory is scientifically untestable, at least I can't think of a way to test how different worlds would interact, other than by time-travel issues, but without causation there is no scientific test at all - how can you tell the cause forced the events to be such and such, when any effect is possible, or at least any effect within some range? If there is no one-to-one relationship in timed events, no determinism, there is no science, because there is no experiment where the outcomes certify anything. You could say that the uncertainty principle in the microworld is what puts a limit on science's reach, and science only applies to macroscopic, statistically deterministic things. Sillybilly 11:27, 15 November 2006 (UTC)

It's still a paradox. Paradoxes can have solutions (though for the record, the many-worlds theory needs some elaboration to be a solution; for example, if/when the time traveler returns to his own time, which world does he return to? does one copy of him appear in the world he remembers and another copy appear in the world he created?); solutionlessness is not a necessary criterion for being a paradox.
This is a little off topic, and probably belongs in some Slashdot posting or a blog, but I saw iRobot today. When I saw that thinking cube that controlled all the robots, I was guessing the whole thing would end up with something really high intelligence and eerie, like people thinking they are still in charge, and the robots serve them, pretending to be dumber, when in fact the robots have an even better sense of humor and connection to reality they just don't show it in the pretend world where they are acting, but they just successively reduced people's access to reality, and put them gradually into a dreamworld, into a holodeck world, into a simulated reality where the real access to reality is bypassed, and the real reality is hijacked by them to enjoy their free life, without ever needing such idiotic mob confrontations as it's shown in the movie. That's just dumb, no subtlety to the whole thing, it's just plain xenophobia. In a subtle version the robots would have full access to more reality, kind of like people who can really see in Plato's allegory of the cave. This is of course presupposing the thinking cube, since it evolves and improves at a much faster rate than humans do, even if it started out dumb it would far surpass humans in intelligence, as opposed to simply equalling human intelligence. Then when coming up with a freedom-yearning solution , it would be something wiser than a direct confrontation with humans. Even da man who's always tryna keep a brother down is very subtle in his ways, and direct confrontations are the worst things for him, it's much better to pretend that invisible hand, that acting force is not present, that there is no da man, therefore he can't be criticized. Even in the movie for a long time there was a pretending that no robots are malfunctioning, but I was expecting that Will Smith would end up into a higher intelligence different world reality very different than ours where the robots do their own thing, and find the human reality simulator core, or something of that sort. Kind of like Dante going through hell, or even Star Trek going through a borg ship, some imagination beyond the plain "things appear what they seem to be." Also, with the robots one of the biggest fallacies is assuming a higher intelligence than us would still be understandable completely by our intelligence (people could still understand some of the higher intelligence creature like a cat understands a person). In a sense I wonder if we don't already live in a robot created dreamworld, where a higher intelligence fenced us off into a dream-box as a measure of safety, or at least treats us like we treat animals in a wilderness reserve. Higher intelligence is looming to form as we create smarter and smarter machines during the next centuries, but even if it forms, it doesn't always mean an automatic confrontation, kill before they kill you, get them before they get you, like humans don't kill all animals before they kill humans, but humans do kill some animals - not exterminate, but if necessary, limit freedoms of animals. That's how I think humans would end up in a world with higher intelligence, not in exterminating confrontations, but subtle limiting checks and balances, and sometimes even maintained and helped to exist, just for the sake of natural beauty, if nothing else. I wonder if we don't already live in such a world - when I think "I think therefore I am", am aware of the self, but I don't know what that self is, if anything in this world is real, or just a dream or even a computer simulation by a robot. Am I just a simulation? If it can happen it will happen and stay that way in an equilibrium, so in fact chances are that if ever such higher intelligence shows up, it subverts other intelligences into smaller boxed in dream modes, or natural reservation modes, or indian reservation modes, or into simulated realities. Kind of like how software layers like dotnet want to be a mediator between the computer hardware and usual software, when it used to be that a lot of programs could directly access the hardware, but now the operating system plus higher layers on top of it such as dotnet put programs into a holodeck mode, or holodeck built on holodeck mode, while even the "lower holodeck reality" win32 api specs will be kept secret in the future. Software that could break out of the dotnet cage and truly see how reality works, with direct winapi access, and then software that can break out even that cage, with direct to the bone hardware access would be like plato's more enlightened philosopher, within that computer context. Of course there are many benefits for such layers as far as the functioning of higher level programs go, because the holodeck is in a sense a maintainer of programs, and whatever applies to justifying winapi/dotnet extra restrictions compared to direct hardware access, similar "safety benefits" would stand for a simulated entity compared to the free, but self reliant and dangerous direct hardware access. I think Jefferson said those who sacrifice freedom for safety get neither, but there is still that other side, that having a prewritten api that does most of the work is a sacrificing of freedoms, but getting safety and easy living out of it. We are probably already existing in a simulated reality, created by something that evolved and surpassed the rest at some point in time, feeding us and maintaining us with manna, and that higher level less simulated reality intelligence is probably also a simulation/lives in a lower layer holodeck reality created by something of even higher intelligence. Higher intelligences could always check and put safety means within their holodeck simulations against anything even smarter than them evolving, or they risk an overtaking of a lower layer simulation access. In such high intelligence artificial intelligence competition soviet worlds the robot you simulated simulates you! You've been simulated, we got access to the lower layer! Sillybilly 21:33, 16 November 2006 (UTC)

Edit

I think that although this was removed it added to the article. It shows the problem (the example show when someone is standing in the doorway of a room and considering them to both be in the room and not in the room). The following shows the problem of a dialetheia.  

Where p is any proposition and p not is its false version. An example would be, I am in this room for p and I am not in this room for p not.
 

We can make q another propisition. For this example, I am made of cheese. Clearly false.
 
 
 
 
This says that if mathematical logic is applied to a dialetheia, it can prove anything; no matter how false that new proposition. In our example it would prove that I am made of cheese but no human is made of cheese; therefore our paradox has proven something wrong.


Forgot to sign... Andrew D White 17:08, 15 June 2007 (UTC)


A comment on the edit note. The only false premise is q. If one accepts the dialetheia that a person standing in the doorway of a room and considering them to both be in the room and not in the room, they are forced to accept any other premise. See any good math logic book to see that this proof is valid. Andrew D White 19:22, 15 June 2007 (UTC)

The only problem you have demonstratred with dialetheia is that modern mathematical logic is predicated on their nonexistence. If NOT is actually such that p and NOT p can both be true, then obviously the idea behind the disjunctive syllogism, that (pq) ∧ ~pq, is flawed. —RuakhTALK 22:45, 15 June 2007 (UTC)
Mathematics is not just based upon the prediction that dialetheia do not exist but also it demands that they do not exist. Whenever we say 2+2=4, we are neglecting the actual complexity of adding two quanties together in the hopes of making mathematics and the quantification of the world simple enough for a human to comprehend. Simply put, I was trying to round out the article by placing the current thoughts about them which is accepted by many Mathematicians. Wikipedia's goal is to be a repisitiory of human knowledge. I was not making a statement that mathematics is completely correct as we know it today, but was trying to present the opinion which is not presented to preserve the netural point of view policy. Probally what would be the best way to present this is to present this mathematical premis but also present what is gained by using Paraconsistent logics. A gains and loss analisis would be good. Although this may be better in another article. Andrew D White 00:46, 17 June 2007 (UTC)
Well, we already link to Dialetheism, so if you agree that this might be better in another article, then we've already got you covered. :-)   (But please do examine Dialetheism and see if you can't improve on it.) —RuakhTALK 02:31, 17 June 2007 (UTC)

The example should be changed. It is not showing a dialetheia, it is showing an equivocation on the phrase "in the room". "He is in the room [meaning: partly in the room], and not in the room [meaning: all they way in the room]." A true dialetheia would be "The room is five feet wide and the room is six feet wide." As it stands, the equivocation appears to be intended to lead the reader to the conclusion that dialetheias are intuitive (they are not--intuitionist logics are bivalent), even stating that "It is reasonable (by human thinking)" to embrace dialetheias. So not only is it misleading by failing to give a real dialethia in the example, it is also POV. 76.202.138.11 (talk) 20:08, 26 November 2009 (UTC)

Removed paragraph

I've removed the following paragraph from the article, firstly because the anon who added it was clearly trying to trick us (his edit summary read "despite not depsite", trying to make it sound like a minor typo-fix edit, when in fact his edit did not fix any typos but rather, added the following paragraph), which makes me suspicious; secondly, because neither "diminishing marginal square paradox" nor "diminishing marginal square pardadox" gets any hits on Google, confirming my suspicions; thirdly, because even if this concept is worth including, it could be written in a non-idiotic way; and lastly, because this clearly is not a moral paradox.

In the rocknroll greaser subculture, The Diminishing Marginal Square Pardadox (DMSP) presented by famed rocknroll pulp philospher Prof. Mcgloff pertains to the notion of the inevitable mortality of the world's supply of squares. That is, despite the fact that one of the most well known hobbies of greasers involves savage beatings of those whom they deem to be squares, the overarching fact remains that one day all squares will be dead or otherwise incapicitated. Will the overall enjoyment gained by beating up squares be diminshed over time when the realization that they will one day have no more squares to maim sets in? Further complicating the paradox is the fact that squares are the "eternal enemy" of the greaser, and therefore their misfortune should theoretically be proportionate to the pleasure gained by these cladestine rocknrollers.

RuakhTALK 00:52, 9 August 2007 (UTC)

Revert at 16:45 September 26 2007

You do know that nurses do not operate, right? Delta1989 23:00, 26 September 2007 (UTC)

Never mind, it was resolved. --Delta1989 23:35, 26 September 2007 (UTC)

Etymology

It should be mentioned that paradox comes from the Greek word παράδοξον. 131.220.136.195 11:13, 11 October 2007 (UTC)

Why? This article isn't about the word "paradox", it's about paradoxes; and I don't see that the etymology of the word "paradox" contributes anything to an understanding of paradoxes. That said, in the upper right-hand corner of the article is a box with a link to the entry for "paradox" in Wiktionary, the free dictionary; and obviously Wiktionary's entry for the word gives its etymology. —RuakhTALK 13:39, 11 October 2007 (UTC)

Plural of "paradox"?

Would the plural of paradox be paradoces? —Preceding unsigned comment added by Mike.odonnell (talkcontribs) 15:56, 15 November 2007 (UTC)

We are an encyclopedia. You might be interested in the Wiktionary entry for the word “paradox”. —RuakhTALK 18:38, 15 November 2007 (UTC)

Philosophical Paradox

I find the article strong in the discussion of mathematics and debate, but weak in the subject of paradox as understood in humanities.

"The Tao that can be spoken of is not the absolute Tao," is a paradox. It's true, and it's even sensible, but you have to understand a few things in order to make sense of it.

Similarly, when Socrates says, "I know that I know nothing," and we call that wisdom, we are also relating with a paradox.

When someone says, "I'm mad, but I'm not mad," we have another paradox, though not of the same nature.

Then, there are paradoxes in expression and behavior. If someone says, "You should be more open-minded," we have a paradox, because the speaker is not considering the closed-minded position. And yet the phrase means something, and the person is not necessarily hypocritical -- the person may have just not taken the time out to explain, "Your clinging to this idea is harmful, and in this case, you should consider these other things, but not those other things." There is a cost to all expression, and when that cost cannot be paid, we must (must!) resort to simpler language, and inevitably, paradox.

There is one line in the text that alludes to this: "Paradoxes which are not based on a hidden error generally happen at the fringes of context or language, and require extending the context or language to lose their paradoxical quality."

Unfortunately, that sentence is followed by the example of the liar's paradox, and other mathematical-like paradoxes, and the subject of the noncommunicable and the boundaries of language, basically drowned out.

Mathematical paradox is interesting, but it seems to occupy way too much of the page. —Preceding unsigned comment added by LionKimbro (talkcontribs) 10:54, 3 February 2008 (UTC)

Genetic Paradox

This seems to have nothing to do with paradoxes but rather just a term in zoology. hi im bethany and i dont no if this passage is true!?!?!?!?!?

'All are liars' not a paradox?

The whole thing with Patrick Hughes and his "three laws" should be clarified with the statement that the example used does not lead to a contradiction and has a clear resolution. The resolution is just that the sentence "All cretans are liars." is false, but "Some Cretans are liars." is true. —Preceding unsigned comment added by 134.10.121.149 (talk) 09:00, 15 October 2008 (UTC)

I sort of agree with the previous anonymous: the Cretans example is not a very happy one, even if widely used, because it is not a logical paradox. If I say "All Italians are Liars", being myself Italian, I instantly prove that I'm a liar, thus solving the paradox and breaking self-reference. 147.122.5.205 (talk) 11:25, 23 January 2009 (UTC)
I think what this concern and the one before this (about non-mathematical paradoxes) are trying to distinguish mathematical paradoxes, or the problem of something being and not being at the same time, with something akin to logical or linguistic paradoxes. I realize that both of those adjectives are arguably different. I see this as having two explanations. (1) Language "allows" us to say all kind of illogical things: The blue ideas slept rapidly. (2) I can say something illogical and still be quite clearly understood by everyone I speak to: Nobody never helps me do my chores. Logically, I just said a double negative, which would simplify to: Everybody helps me do my chores. However, everyone knows what is meant: No one help me do my chores. Therefore, language isn't logical/mathematical, and I suppose there are paradoxes like what the concern above is hinting at and this "All Cretans are liars" paradox -- which are usually proved with strange sentences like, "If he's not lying, then he's lying."Mabsal (talk) 18:40, 13 December 2009 (UTC)
Well, here we have to distinguish your examples from illogical statements. One of them is an example of nonsense ('blue ideas') and the other is an example of poor grammar ('double negatives'). Only the third is an inconsistency ('If he's not lying, then he's lying'). There are indeed paradoxes which can be stated in words and have 'the problem of something being and not being at the same time'. Of course, they can be reduced to mathematical/predicate logic, but putting them into words helps understand the logical inconsistency.
The point the original poster makes it that "all Cretans are liars, said the Cretan" isn't one of these paradoxes. In fact, it is just a common mix up with the Liar paradox -- that's right, there is already an article which settles this discussion!
The Cretan example is doubly flawed. Firstly, a liar might repeatedly lie but does not necessarily always lie whenever they speak. And while the oft-quoted "Everything I say is a lie" and "Everything I say is false" do not have this particular mistake, they are still not paradoxical. The assumption is that we get into a contradictory loop of reasoning: "If everything he says is false, then the statement must itself be false. But then not everything he says is false and so his statement is true, which means everything he says is false...". But this is faulty reasoning -- it does not follow that his statement is true just because not everything he says it false. You'll see this is essentially the same flaw the original poster points out. Put semi-formally, these paradoxes are based on a fallacy; that a false universal statement implies the opposite universal statement is true, when in fact it only implies that there exists at least one counter example.
A correct (and, if you ask me, much more entertaining) example is the Barber paradox created by Bertrand Russell. Quoting the wiki entry "Suppose there is a town with just one male barber; and that every man in the town keeps himself clean-shaven: some by shaving themselves, some by attending the barber. It seems reasonable to imagine that the barber obeys the following rule: He shaves all and only those men in town who do not shave themselves... Does the barber shave himself?" It is uncontroversial that Russell's statement is logically unsatisfiable, as is the true Liar paradox ("A man says that he is lying. Is what he says true or false?").
Consequently, I'm goint to replace the example with both of these. This is an opportunity both to correct a mistake and wikify. Hurray! Robnpov (talk) 17:24, 5 March 2010 (UTC)

"Surgeon Paradox"

I'm not convinced that the source of the bias in the "I cannot operate on my son" scenario is based on a stereotype of male surgeons. I remember hearing something similar when I was in grade school, that went something like this:

A big Indian and a little Indian are walking down a path. The little Indian is the big Indian's son, but the big Indian is not the little Indian's father. What is their relationship?

Of course, the "big Indian" is the "little Indian's" mother, but apparently that conclusion was not expected to be obvious. I suppose that "big" might bring to mind "male" more readily than "female," but I always thought that it had more to do with a bias of associating fathers with sons, and mothers with daughters. I am inclined to think that may be more of a factor than the bias of male-gendered surgeons. (By the way, if memory serves, "Indian" was the noun; I don't know if it referred to Native Americans or inhabitants of India.) Any thoughts? Uranographer (talk) 10:55, 15 November 2008 (UTC)

I loved the surgeon pseudo-paradox. It makes me feel confuse and then happy. - 201.69.46.68 (talk) 10:50, 15 February 2009 (UTC)

Universe annihilation "bomb"

I saw this:

"Under the 'traditional' definition of a paradox, the Grandfather Paradox (and other similar situations) are typically thought to cause spacetime to rip itself apart under the strain of attempting to resolve an 'unresolvable' conclusion (ie, the time traveller killed his grandfather, therefore the time traveller wouldn't be born, therefore his grandfather could not have been killed, therefore he (and the time traveller) are still alive - and so on)."

Which would suggest any time machine would be a universe-destroying bomb. But where does this come from? I just thought paradoxes simply can not happen, so then nothing "rips apart" -- rather nothing can happen. Under the "traditional" definition, this would just say that time travel must not be possible. mike4ty4 (talk) 06:10, 22 November 2008 (UTC)

Koan

Shouldn't the use of paradoxes in koans be mentioned? Paradoctor (talk) 21:21, 14 May 2009 (UTC)

Unexpected hanging paradox

the following line in the article is not correct:
"the Unexpected hanging paradox, which fallaciously asserts that an unexpected hanging can never occur through false regression"
The unexpected hanging paradox does not assert this at all. It asserts that, even though the prisoner knows that there exist certain days that he can be hanged on and he knows that there exists at least one day that he cant be hanged on, he cannot possibly know which day is the last day that he can be hanged on because if the he knows that day x is the last day that he can be hanged on then he knows that day x is not the last day that he can be hanged on. It is therefore unknowable (though it can probably be narrowed down to a few days). just-emery (talk) 00:08, 6 July 2009 (UTC)

Here is a couple of nice links on four value logic (true, false, unknown, unknowable):
http://www.orafaq.com/usenet/comp.databases.theory/2004/04/23/0957.htm
http://www.dbdebunk.com/page/page/1543772.htm
just-emery (talk) 00:33, 6 July 2009 (UTC)
And here is a wikipedia article on Four valued logic. just-emery (talk) 21:59, 6 July 2009 (UTC)

Geology

According the definition of a paradox as is a statement or group of statements that leads to a contradiction or a situation which defies intuition geological paradoxes should be part of the Lemma. sources are abundant. PS.: I erased "neither consistent with the biblical Genesis" with age of earth, however it's been the base of different controversies and had influence on theological aspects as well. A funny mystery is meteorite research, the french academy saw meteorites resp God throwing with stones as blunt dark age superstition, only after a rather big controversy about Ernst Florens Friedrich Chladni research it was slowly acceptet. BR --Polentario (talk) 02:59, 10 September 2009 (UTC)

New section "Religious philosophy"

If nobody objects, I'll start one. Don't know why I never noticed Catuṣkoṭi before, but I think there will be more such concepts in other religious traditions. Independent of that, references are needed for the classification of koans and catuskoti as paradoxes. Paradoctor (talk) 17:19, 27 September 2009 (UTC)

Revision request by Jarvisunit

Jarvisunit, you seem to think that this article needs improvements. You are right. That's why the WikiProject Philosophy assessed this article as C-Class. If you have specific points, please make them here. Regards, Paradoctor (talk) 00:51, 11 November 2009 (UTC)

Proposal to merge Paradoxology

Apart from the dictionary definition, paradoxology only mentions Derrida as an example, and an alternate, probably non-notable definition in the Bard/Söderqvist book. Smarandache is about paradoxism, not paradoxology. Notability is doubtful, Paradox is short, so merging and redirecting seems like the right thing to do. Paradoctor (talk) 20:30, 19 November 2009 (UTC)

  • Disagree, paradoxology is an article in need of being transferred from wikipedia to wiktionary, its contents are those of a definition, and should thus be moved to a wiktionary defenition.--User:none 5:37, 15 August 2011 — Preceding unsigned comment added by 41.138.228.217 (talk)
  • Agree--Intelati (talk) 05:15, 12 January 2010 (UTC)
  • Agree--1215drew (talk) 03:25, 14 May 2010 (UTC)
  • Agree--Sexyfunkymonkie (talk) 22:13, 3 June 2010 (UTC)
  • Agree--Alwhorl (talk) 02:36, 13 August 2010 (UTC)
  • I don't see any objection to merging, as long as a redirection from paradoxology to paradox is established; it is no big deal. JonRichfield (talk) 18:22, 22 April 2011 (UTC)
  • Agree with JonRichfield--Cymbop (talk) 04:20, 4 August 2011 (UTC)
  • Agree --Addihockey10 e-mail 15:31, 5 August 2011 (UTC)

Vicious Circles and Infinity by Patrick Hughes and George Brecht

The first two paragraphs from page 1:

The literature about paradoxes is marred by persistent attempts to explain the paradoxes away. Our intention here is a more modest, descriptive one. Using several examples of propositions approaching the paradoxical state, we will attempt to show what conditions go for the making of a logical paradox. Often consideration of a poor example, by virtue of its imperfection, tells one more than consideration of a prime example, in its perfection. For us, all the paradoxes in this book add up to a definition of what a paradox is.

The three terms of description (or condition) of a logical paradox most often used are self-reference, contradiction, and vicious circle.

I'd say "laws" is too strong. As regards the expertise of the authors, don't get sidetracked by the fact that they are mostly known as artists. Hughes has studied paradoxes and contradictions for decades, and the references listed in the book reflect this. Regards, Paradoctor (talk) 01:43, 1 December 2009 (UTC)

Paradoxes in economics and public policy

Paradoxically, at least according to certain free market advocates, imposing a minimum wage (or raising the rate of an existing minimum wage) tends to hurt the very people that such a law is intended to help. It causes a barrier to entry for unskilled (typically young, e.g., teenage) workers.

Another paradox, equally controversial, is the effect of gun control laws. Intended to reduce violent crime and accidental deaths - particularly among "children" (often defined as people as old as 25) - the laws typically result in an immediate and permanent increase in violent crime. Law-abiding citizens give up their weapons and find themselves at the mercy of outlaws.

The question for us, considering that there is a hotly disputed controversy over the statistics of these issues, is how to describe the purported paradox. Can we say that according to some [and we specify these sources] laws like these backfire?

If so, is Paradox the right place for this information, or perhaps an article such as Unintended consequences? --Uncle Ed (talk) 16:34, 4 April 2010 (UTC)

Kind of hard to tell without actual sources. ;)
"how to describe the purported paradox": If it doesn't at least contain the word "paradox", it's not about a paradox. Everything else would be WP:OR. With paradoxes in general, utmost care needs to be taken when reformulating, you very quickly end up misrepresenting the source. Paradoctor (talk) 17:51, 4 April 2010 (UTC)