# Philosophy and the bent stick…



## TheocraticMonarchist

I heard of a philosopher who placed a stick (maybe it was a boat ore) into some water and it appeared to “bend”. He concluded that humans could not trust their senses because they could be deceived. Does anyone know who this philosopher was and what school of thought this represents? 

I don't remember much about this story, but it may be useful for a paper I'm writing. Any help would be appreciated!


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## Grymir

That's an easy one. I heard it in college. But when I mentioned to the teacher that we _know_ that the stick is bent, and we can know for _certain_ that its bent, and we use our senses to know the truth, well, that caused all kinds of consternation with the example with the class.

It's similar to the elephant example. There was one person who knew the truth about the elephant, and they try to divert attention from him. But that person is there in the story.

-----Added 3/22/2009 at 10:02:55 EST-----

I know J L Austin wrote about it, as did Ayers.


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## CNJ

"Refraction" of light or some such property causes the stick to look bent, I believe. I think it is Science and not Philosophy.


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## TheocraticMonarchist

Isn't this some sort of ancient philosophy, though? I think Augustine, or Acquaints refuted it...


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## Davidius

TheocraticMonarchist said:


> Isn't this some sort of ancient philosophy, though? I think Augustine, or Acquaints refuted it...



Who is Acquaints? Do you mean Aquinas?

It's some form of skepticism. The argument goes that if our eyes can be fooled sometimes, it's impossible to know when we're being tricked by an optical illusion and when we aren't. Gordon Clark and John Robbins employed this argument to defend their "rationalism." I do not know of any particular individual who refuted it, but if I had to guess, I would say Aristotle or Aquinas, since they were empiricists.


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## TheocraticMonarchist

I should pay attention to spell check, sorry.


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## CatechumenPatrick

It was used, probably not originally, by the Greek sceptic Pyrrho and recorded in Sextus Empiricus' _Outlines of Pyrrhonism_, mode number 5 I believe. It is meant to show that variations in location and position of an observer will change how an object appears. It is not by itself an argument for scepticim—Empiricus uses it and the other ten modes to force the non-sceptic into giving a proof or argument in defense of why the stick appears bent and why this is not a sceptical problem, which will lead to an infinite regress in justification as the proof or response will need justifying, and so on. Empricius' text is one of the most important works in philosophy, and you should all read it.



Grymir said:


> That's an easy one. I heard it in college. But when I mentioned to the teacher that we _know_ that the stick is bent, and we can know for _certain_ that its bent, and we use our senses to know the truth, well, that caused all kinds of consternation with the example with the class.
> 
> It's similar to the elephant example. There was one person who knew the truth about the elephant, and they try to divert attention from him. But that person is there in the story.



Do you really mean that every time you see a (straight) straw in water, a stick in water, an oar off the side of a boat (etc.), the stick is really bent in the water and then returns to normal straightness every time you take it out?


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## steven-nemes

Maybe he means we know it's _straight_...


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## Grymir

Yes indeed. Steven hits a grand slam. We know it's straight. We know that the water bends the image. We know that it's an image. We know all about it. To use it as an example of how we can't trust our senses is easily demythologized. So is it when people deny the basic reliability of sense persecption. Which is what they are ultimately trying to do.


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## steven-nemes

How do we know that it is straight?


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## Grymir

From the vantage point of the person telling the story. The forgotten link in alot of stories.


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## Zenas

In order to posit our senses can be deceived, the questioner must realize there is a deception occurring. In order for him to realize this, his senses must not be deceived, but dependable. 

It is true, an illusion is occurring that can fool your senses. However, because of those same senses, you realize that is isn't the truth, but only an illusion, and thus the deception is a farce. Your senses are therefore reliable.


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## mgeoffriau

If the question is the reliability of the senses, how does appealing to the senses themselves solve the problem? Begging the question, isn't it?


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## BrianLanier

mgeoffriau said:


> If the question is the reliability of the senses, how does appealing to the senses themselves solve the problem? Begging the question, isn't it?



This is absolutely right. Precisely why the answers given thus far are inadequate.


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## Christoffer

Doesn't the bent stick in the water prove one thing, that there is a difference between the sense data and the thing known? I guess it is called appearance and reality.

Assuming, of course, that everybody agrees that we know that the stick is straight. If we cannot know, then neither can we know if there is any reality at all.

Isn't this the classic problem that Hume and the others wrestled with?


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## Grymir

BrianLanier said:


> mgeoffriau said:
> 
> 
> 
> If the question is the reliability of the senses, how does appealing to the senses themselves solve the problem? Begging the question, isn't it?
> 
> 
> 
> 
> This is absolutely right. Precisely why the answers given thus far are inadequate.
Click to expand...


Actually, this is an excellent example of checking your premises. The question raised is about the reliability of the senses, but it is not appealing to the senses to solve the problem. You appeal to reason and the mind to solve the problem. So there is no begging the question.


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## mgeoffriau

Grymir said:


> You appeal to reason and the mind to solve the problem.



A priori or a posteriori?


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## jambo

TheocraticMonarchist said:


> I heard of a philosopher who placed a stick (maybe it was a boat ore) into some water and it appeared to “bend”. He concluded that humans could not trust their senses because they could be deceived. Does anyone know who this philosopher was and what school of thought this represents?



Its not the senses I wouldn't trust but the philosophers.


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## Skyler

Ugh. Now I have a headache.


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## SolaScriptura

I believe there's a scene in The Matrix in which the boy talks about bending a spoond and realizing that the spoon doesn't bend... or something like that.

I like The Matrix. 

Because there's killin'.


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## steven-nemes

Doesn't the notion that our senses can deceive us imply that there are times when the senses don't deceive us? The notion that our senses have been wrong before imply that at some time in some way, the senses have been right? Otherwise, what are you comparing them to to say that they are deceiving?

I should think the argument against the senses is not that they deceive, but that we don't know if they are ever right, because of the contradictory information we get from them: with the example of the stick, we say that our senses are unreliable because they deceive us into believing the stick is bent when at other times it is straight. I would deny that they deceive us in showing to us that it is bent, but rather that we have no way of knowing whether or not either one is actually true because we have nothing to compare it to. William Lane Craig once answered a similar question in the following way: because we cannot go "outside" our senses to verify them, we can only assume them to be true until we have reason to think otherwise (same true with memory, etc.).


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## Confessor

As Davidius implied, the entire argument is based on the fact that anything less than certainty must be rejected as knowledge; all knowledge must be infallible.

This Cartesian skepticism is self-refuting though, for if I deduced Cartesian skepticism to be true, then I did it by means of my mental faculties, yet those have mistaken me before. Therefore I cannot know that Cartesian skepticism is true.


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