sense and perception

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rcs
 
Reply Fri 24 Jul, 2009 07:32 am
Descartes did not believe that the information we receive through our senses represents the external world accurately. True knowledge only comes from pure reasons.Do you agree with Descartes that sense can be deceived. Can you help me find some examples?
To what extent will you trust the deductions made on the grounds of sense and perception?
 
Caroline
 
Reply Fri 24 Jul, 2009 07:38 am
@rcs,
Well what others see and perceive can be totally different to what the next person sees. Also have you ever believed you thought you saw something but it was a trick of the light or something, so you can never be totally sure all of the time what your senses are telling you. You can all agree that the tree does exist but there will be different perceptions of that tree, so the common thing you can agree on is that the tree does exist but you may not agree on say the colour of it's leaves, one might see it to be dark green the other dark brown.
 
rcs
 
Reply Fri 24 Jul, 2009 07:46 am
@rcs,
oh, ok... thank you very much
 
Caroline
 
Reply Fri 24 Jul, 2009 07:59 am
@rcs,
Erm....... I haven't read alot on Descartes so I wasn't referring to him.
 
jgweed
 
Reply Fri 24 Jul, 2009 08:02 am
@rcs,
That we can be deceived, or better, confused by the sense impressions we receive can be illustrated by the tower, which at a distance was seen as round, but on closer view was actually square. In this example, we were deceived by the shape, although we were correct in seeing the object as a tower.

Another example, is the desert mirage, which can be seen and "accurately" described by people in the group. It is, roughly, the same mirage they see, but the mirage does not exist.

I am not sure that Descartes would hold that reason (or "pure reasons") gives, or could give, truth about the world, although he seems convinced that mathematics was "more true" than sense impressions.

Another question needs to be considered in this discussion. If we are deceived (or confused) about sense impressions, how do we know that these impressions are "false?" In the case of the tower we walk toward it, walk around it, feel its stone structure, and say, "Well it looked round to me, but now I know I was mistaken." In the case of the mirage, one of the group tells the others, "it's only a mirage, there is no lake in the distance."

We only trust those sense impressions we know, or can at least be relatively certain of being able to prove if the occasion warrants, to be true.
 
VideCorSpoon
 
Reply Fri 24 Jul, 2009 09:59 am
@jgweed,
rcs;79256 wrote:
Descartes did not believe that the information we receive through our senses represents the external world accurately. True knowledge only comes from pure reasons.

I can agree with you to a point that Descartes did not believe that the information we receive through our senses (a-posteriori knowledge) represents the external world accurately. This is one of the fundamental quantifiers that make Descartes a rationalist to begin with, instead forcing him to lean towards innate ideas (a-priori knowledge) as the source of human knowledge. But there are more caveats to Descartes rationalism. You also hint at what I am getting at because you refer not to senses that represent the world alone but represent them accurately. This is a fundamental premise in Descartes Meditations, which is that there must be a degree of what we can know through rationalism to be clearly and distinctly known. This is a primary issue that Descartes examined in his previous book Discourse on Method in which he must deliver upon in Meditations. Descartes must as Discourse implies, doubt everything (except what can be known clearly and distinctly), analyze down to the simplest component, reconstruct them so that the method is as clearly and distinctly know as before you had deconstructed them, and enumerate over and over again.
rcs;79256 wrote:
Do you agree with Descartes that sense can be deceived.

As far as Descartes is concerned, sure. The first meditation gives a pretty wiz-bang account of universal doubt. As far as the first meditation is concerned for example, most things cannot be trusted to be known clearly and distinctly by whatever it is that accounts for these thoughts (because he has yet to rationalize himself into existence). Look at the dream argument in med. Med. On First. Phil, Meditation
rcs;79256 wrote:
Can you help me find some examples?

The best place to look is probably within the framework of Meditations. In Meditation 2, Descartes gives what I would consider a perfect example of what you may be getting at, namely the ball of wax argument. To begin with, Meditation 2 is essentially basing itself off of two derived points, that; Descartes has mental states therefore he exists, and that it is an a-priori (before the senses) form of knowledge. As a side note, this is the true interpretation of the conclusion of the universal doubt argument. "I think, therefore I am" (cogito ergo sum) comes later in another one of Descartes books. Descartes specifically says Res Cogitans (I am a thinking thing) which implies the mental faculties involved rather than the whole of his argument encapsulated in one neat and tidy saying given later on for ease of use. But anyway, the ball of wax argument is essentially resuming his method, namely that after everything is doubted, he must now construct what he knows clearly and distinctly. It is essentially drawing a distinct line between the fundamentals of empiricism (yet to be conceived in its modern form by Locke) and rationalism (which Descartes does not attribute to himself at this point). It is in this example that Descartes proves that what is known is known by reason and not by sense.

The ball of wax argument goes something like this. Suppose I have a ball of wax fresh from the beehive. It has a certain amount of qualities, such as the fact that it is round, yellow, etc. Take all of these properties and label them Wax #1 with qualities 1-10. Now suppose I put Wax 1 with qualities 1-10 next to the fire. Inevitably, the ball of wax loses its size, shape, color, etc. It in essence becomes a different ball of wax, namely Wax 2 with qualities 1-10. This seems like a no brainer, but this was huge when Descartes posited this. We know that Wax 2 is the same ball of wax as Wax 1. But how do you rationalize it. It's not as simple as saying "I saw the ball of wax as it melted" because there is there very real possibility that you blinked, turned around, etc. Descartes specifically points out that you cannot know the wax in either of its forms by its properties (color, shape, etc) because the properties have changed. So a "thinking thing" has to deduce via some form of a-priori capacity that that there is an understanding beyond properties that "thing" already understands.
rcs;79256 wrote:
To what extent will you trust the deductions made on the grounds of sense and perception?
An Essay Concerning Human Understanding
 
William
 
Reply Fri 24 Jul, 2009 10:57 am
@rcs,
RCS,

Personally, I have never questioned what my senses detect in my personal reality. It is only when others enter it and offer what they perceive from their own is when I begin to doubt. We don't like being alone. That is not our nature. We are a social bunch and are designed to coexist. Then why don't we? And that is a matter of opinion. Ha. Here is the rub. "To thine ownself be true".............but even that can be misconstrued as we offer our truth or our "opinion" to others in hopes that we can become "social" and agree. The rub is we want others to agree with us so we don't have to change; they do. Ha. fat chance!

"I think, therefore, I am" is a great concept if you want to exist alone in this world. Be my guest. Have a ball, just don't bring you selfishness into my world in hopes that I will share in that world your mind has created that only pleases you. Now "we think, therefore, we are" changes everything. Ah, but that too can even be misconstrued; Damn this can get confusing? Only if we let it, IMO. You see, that is also the opinion of another who trying to force us to agree with their personal opinion that only serves themselves. Wow, this can get out of hand, can't it. Hmmm? It seems he wants to assmeble his own mob, huh? Yet the "we therefore we are" is the only paradigm that makes sense; it the language that keeps us from communicating is what is at fault. It is more offensive and threatening than it is sublime and benign. The selfishness of the ego is our biggest obstacle in that communication as we are afraid to let our "defenses" down and alter the way we think. it is what protects us from the opinions of others and that makes us lonely when the truth of the matter is we desperately want to belong so we will not be alone. We just want to "call the shots". What an impasse?

As far as the tree, hell, close your eyes, it will cease to exist. End of discussion. Let's not complicate an already complicated situation! Ha. And the mirage,what are you doing in the desert in the first place? Ha. Why would life exist where there is no life? Unless we can turn that barren land into fertile ground. Hmmm? The heat of the sun will bake your brain. I've heard that somewhere before. Or heat of the "son"? Hmmm?
Wow, I have to think about that one a little more. Snicker, snicker.

I have never had a problem distinguishing what is real and what is not real. The thought has never occured to me. I look at a tree and see the beauty of it, the oxygen it provides me and the shade from the heat and the wood it supplies in the cold to provide the heat that I need as I plant a seed that will continue's the process and grow another one.

Now you guys can ponder Decartes all you want, me I rather sit beneath that tree and relate to my granddaugher how lucky we are to have that tree. And when you tell it thanks, it literally makes the leaves greener in appreciation. :a-ok:

William
 
chad3006
 
Reply Fri 24 Jul, 2009 01:41 pm
@rcs,
I've been fooled by my senses before. As a child, shiny tanker trucks on the highway miles away, appeared as "flying saucers" until I inspected more closely (I've always been a skeptic). Echoes from nearby barns can disguise the location of coyotes howling in the evenings. My senses do fail me from time to time, but I usually can reason through them to find something resembling truth. But then, I'm not that familiar with Descartes.
As jgweed said above, at some point we do have to trust our senses, I can't think of any other way we interact with our physical world, but through our senses. Are there any examples of our reasoning failing us, and we must depent ultimately on our senses? I personally know some people who's reasoning is suspect (to me anyway.) I suppose one would find it difficult to judge one's own reasoning.
 
parker pyne
 
Reply Fri 24 Jul, 2009 08:55 pm
@chad3006,
chad3006;79380 wrote:
I've been fooled by my senses before. As a child, shiny tanker trucks on the highway miles away, appeared as "flying saucers" until I inspected more closely (I've always been a skeptic). Echoes from nearby barns can disguise the location of coyotes howling in the evenings. My senses do fail me from time to time, but I usually can reason through them to find something resembling truth. But then, I'm not that familiar with Descartes.

Was that your senses deceiving you, or your mental interpretation of those senses decieving you?
 
kennethamy
 
Reply Sat 25 Jul, 2009 06:42 am
@parker pyne,
parker pyne;79410 wrote:
Was that your senses deceiving you, or your mental interpretation of those senses decieving you?


Senses are dumb. We interpret our senses. Sometimes well, sometimes badly.
 
rcs
 
Reply Sat 25 Jul, 2009 06:48 am
@rcs,
wow, thx a lot.. btw, I am still confused about the question "To what extent will you trust the deductions made on the grounds of sense and perception?". Could you help me answer the question? Are there any examples which are similar to the wax that Descartes use? thx
 
VideCorSpoon
 
Reply Sat 25 Jul, 2009 09:58 am
@rcs,
If the question is asking you in general whether or not you can trust the deductions formed from sense and perception, then I suppose you don't need to stay within the realm of Descartes philosophy. The answer I have applies both to this questions and to more examples.

Suppose you were to give an example from the other side of the table, namely, the empiricist camp. Besides the refutation against innate ideas, John Locke in An Essay Concerning Human Understanding has a great bit on "representational models of perception." Think of that notion like this; Think of yourself at one end of the room and the "external world" on the other. Intermediate ideas and sense perception wedge themselves between you and the external world. That wedge forms our skeptical inferences that rip the person apart from the external world, forming what Locke wonderfully calls the "veil of perception." Fantastic, right? Hilariously, most people that full heartedly endorse empiricism (under their own personal notions) suppose that physical objects around us are more or less as they perceive them. Many think that we have direct access to "sense data" or "perceptions." Ironically, Locke, who essentially is considered the modern father of empiricism did not think so. So that is one example and "personal" response. It essentially says that I may not trust the deductions I make on perception and sense because there is a medium that "veils" the truth of the external world at the end of the room. I can sure as heck fight that though, and Locke goes to great lengths to explain that in ways such as primary and secondary qualities, but the veil is still there. But you could come up with a whole bunch of analogies on this note, like a camera for example. The camera is your medium through which you, the person, views the external world ad capture "ideas." However, light distortion, aperture settings, etc. can "veil" the true image. Although, the camera itself is the problem if you think about it because Locke essentially wants to cut the camera out of the equation. To illustrate my point (LOL);

http://i26.tinypic.com/14lsgat.jpg

But there are a ton of other notions you can use though. If you follow Berkeley's principles for example, to be is to be perceived (esse est pecipi). Essentially, (in a widely regarded opinion) the minute you turn way from the table across the room, that table ceases to be and comes back into play when you turn back round. Immaterialism is pretty far off though, but is definitely a great perspective to take into account. So, you could say that actually the deductions made on sense and perception are everything
 
kennethamy
 
Reply Sat 25 Jul, 2009 10:48 am
@VideCorSpoon,
The story goes about Leo Tolstoy, the great Russian novelist, that after he read Berkeley, he faced a table, then he suddenly turned his back on the table, and then suddenly faced the table again, so that he would catch the table in the act of disappearing. In any ordinary context, that kind of behavior would be certifiably mad. Thus philosophy can lead you to do nutty things.

The "veil of perception theory" argues from the premise that because sometimes we make perceptual mistakes, we are always making perceptual mistakes, Obviously, an invalid argument. In any case, it is one thing to say that we sometimes make mistakes of perception, so that things are not always as they seem. It is quite another thing to conclude that we are all suffering from the mass hallucination that there are object external to us.

Why is Idealism (immaterialism) a great perspective, when it is obviously both false and crazy?
 
jgweed
 
Reply Sat 25 Jul, 2009 12:01 pm
@rcs,
""To what extent will you trust the deductions made on the grounds of sense and perception?".

All of us live in a realm where we don't actually make deductions about sense data unless something comes before us that "doesn't fit," and then we have to attend more carefully to the sense-data. If I get up in the morning and want to make coffee, I do not stand in the kitchen and become a logician; I go to the coffee pot and make coffee. When I visit a friend and am confronted with something complex and shiney that "looks like" it may be a coffee pot, I act differently and think differently (and I suppose conclude differently).
Most of the time, we can make (if we so choose) perfectly good deductions from sense-data we "have confidence in;" when we are less sure that we perceive correctly, then we make a more or less "probable" conclusion about it.

Descartes might muse about the lump of wax, but he kept the fire in the fireplace stoked.
 
richrf
 
Reply Sat 25 Jul, 2009 01:57 pm
@rcs,
rcs;79256 wrote:
To what extent will you trust the deductions made on the grounds of sense and perception?


I do not think that my senses deceive me. They so what they do. However, there may be disagreements between what I perceive and what others. Happens ALLLLLL of the time. And then there is discussion. Sometimes we reach consensus, and we call that real, and sometimes not, in which case it is an open question.

There are things that people are able to very quickly reach consensus, but you may want to observe how many things remain open. And more that that, there are some many things that people agree on for general communication, but once they begin discussing something, all kinds of disagreements are revealed. So they thought there was consensus, but there really wasn't and at that moment, reality changes.

So, for me, reality is fluid and is dependent upon how firmly a group of people may agree on a specific aspect of their individual and collective beings. It is basically minds trying to get on with life. Smile

Rich
 
VideCorSpoon
 
Reply Sat 25 Jul, 2009 03:19 pm
@richrf,
Kennethamy,thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone, till he rebounded from it -- "I refute it thus." It's funny though, because I have heard various accounts of how the line is delivered and what was actually said. In this case, it takes places in churchyard face to face with Berkeley. In another version, I have heard that Berkeley, having arrived late at night to Johnson's house, knocked on the door. In reply to Berkeley's knock, Johnson asked for Berkeley to walk through the door with his eyes closed, to which Johnson stated "Thus I refute thee." Oh those eighteenth century hooligans and their points to prove. Blather and hurrumph I say!

On your interpretation of the Berkeley's perception theory, that's a very interesting way of looking at it. Definitely a good point. I like it because it leans towards perceptions to begin with rather than the basis of material substance. It seems like Berkeley could very well have cut out a lot of the excess to get at that. But I don't know if you can apply any sort of truth or falsity to Berkeley's argument though. It is above everything else an exercise in abstraction wherein everything is immaterial except for so-called spirits. But I think Berkeley is getting more at the fundamental ontological basis of things, much like Descartes was getting at. Descartes doubted everything except for mathematical certainties immune from doubt. Berkeley pretty much assumes the same thing with his spirits which I would assume are more atomistic or corpuscular in notion. But on the whole, idealism is pretty far off, even for its day. Not at all like Locke or Hume.

richrf,

So you would say that your perceptions are true but the perspectives
 
richrf
 
Reply Sat 25 Jul, 2009 04:43 pm
@VideCorSpoon,
VideCorSpoon;79504 wrote:
richrf,

So you would say that your perceptions are true but the perspectives of those perceptions are what throw everything into turmoil.


I would put it a little different, since the word true has a connotation that I do not subscribe to.

I would say that the senses combined with my brain/spine nervous system are the mechanisms that I use (my mind/consciousness) to tune into the world, just like a TV set (Sheldrake's model). That is the information that I receive and it is the way I perceive the world.

Now, other minds may have mechanisms (senses, etc.) that are tuned slightly differently than mine. Some may be extremely different, for a variety of reasons. So, in order to reconcile the differences we get together and try to form a consensus of what is out there. Call us co-explorers who are sharing findings of our exploration of the universe.

Sometimes we can reconcile, sometimes we say we are reconciled when we are not, and sometimes we are unreconciled. It depends upon the object that is being discussed and the group think. Consensus is very fragile in many cases and subject to change all the time.

Quote:
That sounds a great deal in line with Leibniz and modandistic theory, where the universe is a plenum filled with monads (forms of reality) and that the dominant monad is the one monad that reflects the world most accurately.


I would not say there is a way to view the world accurately, since it is constantly in flux. I would say that some views may prevail for one reason or another and those views may change over time as the minds/consciousness continue their exploration, learning, and mutual communication processes. The end result is to just keep creating new things so we don't get bored. Smile

Quote:
It would seem like, fitting your viewpoint in with Leibniz, that everybody in everybody's perspective (they themselves different and independent monads) are observing a phenomena and coming to some conclusion resulting in a dominant monad.


In my view, there is no external phenomenon, per se, to view. Everything is co-mingled. Matter, energy, mind, consciousness. Everyone and everything is mutually affecting each other all the time. It is like waves colliding in an ocean. Where does the wave begin? Where does it end? Observe what the waves can create when they are spiraling into each other. All kinds of shapes and patterns.

Quote:


Yes, I understand Liebnitz view, but he believes in an external object that is constant, unchanging, and can be accurately understood. I do not share this notion, because I observe flux and change. Constant movement. So I am OK with never noing anything for sure, since there is nothing for sure to know.

Hope this explains my point-of-view and thanks for your comments.

Rich
 
ACB
 
Reply Sat 25 Jul, 2009 07:49 pm
@richrf,
richrf;79508 wrote:
I would not say there is a way to view the world accurately, since it is constantly in flux.


But even if it is in flux, couldn't it be viewed accurately at any given moment? And couldn't the process of change itself be viewed accurately?

Quote:
The end result is to just keep creating new things so we don't get bored. Smile


I would be content to keep discovering new things.

Quote:
In my view, there is no external phenomenon, per se, to view. Everything is co-mingled. Matter, energy, mind, consciousness. Everyone and everything is mutually affecting each other all the time.


If something is affecting you, that thing must (by definition) be external to you. Otherwise you would be affecting yourself.

Quote:
Yes, I understand Leibniz view, but he believes in an external object that is constant, unchanging, and can be accurately understood. I do not share this notion, because I observe flux and change. Constant movement.


But, as I stated above, change does not necessarily prevent accurate (sequential) observation and understanding. The world may be in constant flux, but it is not totally chaotic.
 
richrf
 
Reply Sat 25 Jul, 2009 08:08 pm
@ACB,
ACB;79535 wrote:
But even if it is in flux, couldn't it be viewed accurately at any given moment? And couldn't the process of change itself be viewed accurately?


Don't think so since information cannot be passed instantaneously and without affecting the object. Just look at the ocean. The moment you try to describe it it has changed.

Quote:
I would be content to keep discovering new things.


Yes, but what you are discovering is creating new things in your mind - e.g. ideas.

Quote:
If something is affecting you, that thing must (by definition) be external to you. Otherwise you would be affecting yourself.


Not necessarily. Waves affect each other yet are all part of and connected to each other by the same ocean. This is what quantum seems to act like.

Quote:
But, as I stated above, change does not necessarily prevent accurate (sequential) observation and understanding. The world may be in constant flux, but it is not totally chaotic.
I'm not sure it is chaotic though some theories seem to proclaim so. It seems certainly to be more complex than any one mind can perceive.

Rich
 
kennethamy
 
Reply Sat 25 Jul, 2009 10:14 pm
@jgweed,
jgweed;79481 wrote:
""To what extent will you trust the deductions made on the grounds of sense and perception?".

All of us live in a realm where we don't actually make deductions about sense data unless something comes before us that "doesn't fit," and then we have to attend more carefully to the sense-data. If I get up in the morning and want to make coffee, I do not stand in the kitchen and become a logician; I go to the coffee pot and make coffee. When I visit a friend and am confronted with something complex and shiney that "looks like" it may be a coffee pot, I act differently and think differently (and I suppose conclude differently).
Most of the time, we can make (if we so choose) perfectly good deductions from sense-data we "have confidence in;" when we are less sure that we perceive correctly, then we make a more or less "probable" conclusion about it.

Descartes might muse about the lump of wax, but he kept the fire in the fireplace stoked.


I think that if we use sense data as data, we make inductions, not deductions from them. Only inductive reasoning yields probable conclusions from true premises. Deductive reasoning yields certain conclusions from true premises. So, if I have a sense-datum of white when looking out of the window, I may conclude that I see snow on the ground, But that is an inductive, not a deductive conclusion, for it is only probabilistic. Descartes called his doubt about the world, "metaphysical" or "hyperbolic" doubt. He did not doubt the existence of the fire in his fireplace, nor even the existence of the fire. But he did point out that his inductive reasoning from his sense-data to the fire, or the fireplace, was inductive, and not deductive, and so, left room for doubt. Exaggerated as the doubt might be. He therefore wanted his knowledge of the world to be so justified that there was no room for doubt, and that, of course, meant deductive justification from certain premises. Thus he began from the premise, that he existed, and then, deduced (not induced) further truths from that basic certainty.
 
 

 
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