A question for scientists: Primary and Secondary qualities

[Dymanic]

Originally posted by Suggestologist

Since this all ad hominem, I'll just pretend you didn't write this part.

Disregarding what others have to say is something you appear to be pretty good at, but I'm willing to risk a few characters to try to help you understand what ad hominem means. This is Latin for, "to the man", referring to an argument based on attacking the author of an idea, rather than the idea itself (or presenting the reputation of an author as validation of a particular argument, rather than presenting the strengths of the argument itself).

Maybe a couple of hypothetical examples will help you see how your use of this term was misapplied above: If I were to say, "Advocating the primacy of personal experience over scientific study is an idiotic point of view; this is what is proposed by that Suggestologist fellow, and anyone can see what an idiot he is" -- that would be an ad hominem.

Whereas if I said, "Advocating the primacy of personal experience over scientific study presupposes that a solitary individual can, by simple observation, surpass in understanding the collective efforts of countless others who came before him, and is therefore a naive, self-centered, and arrogant point of view" -- that wouldn't be an ad hominem. See the difference?

 

[Stimpson J. Cat]

davidsmith,

I justify it based on a scientific analysis of my experiences.
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Your inference is hidden in your above statement. Your scientific analysis has already made the inference you are trying to justify. It's circular reasoning

What inference? What are you talking about? I assume the premises of science, and then based on those assumptions, I infer things about reality from my experiences. On what basis are your claiming that my scientific analysis is based on an inference I have already made?

And once again, the "circular argument" accusation is not valid here, because I am in no way claiming to be able to prove that some claim is true, much less trying to do so by assuming that it is true in the process.

What exactly is it that you think we are trying to "validify". I have been attempting to explain my position, not to provide evidence or arguments to support it. I can hardly hope to convince you, or anybody else, that my position is reasonable, if you don't even understand what my position is.
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I understand your position to enough extent to point out the inconsistencies in it. We are trying to validify the inference of objectivity that is made on the basis of certain experiences but not others.

You clearly do not understand my position at all, because if you did, you would understand that my assumption of objectivity is not an inference at all. it is an assumption.

In other words, we are trying to validify why length is said to objectively exist as a property of an object but colour or smell is not.

I have already explained why this is the case. It is because color and smell are experiences we have, and length is a property of an object which we do not experience at all, but instead assign to the object based on logical inferences from our experiences.

Why is that so difficult to understand?

No experience "constitutes" the length of an object. The length of an object is inferred from our experiences.
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Ok, a little semantic misunderstanding there. Thats ok, I shall rephrase.

If you say that all experiences are brain processes then the experiences that you use to infer the length of an object are also brain processes, just like the observations that constitute a hallucination are brain processes.

Better ?

Sure. And this clearly illustrates what the distinction between inferred properties like length, and our direct experiences, is.

Me: You infer some experiences to denote objective properties of objects while others brain processes you do not.

Stimpy: No, I extract information about objective properties of objects from my experiences. There is no "experience of length", or "experience of mass", etc...
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Am I not saying the same thing there ? Ok then to be clear, you infer that you are extracting information about objective properties of objects from your experiences.

No, I assume that the premises of science are valid, and from this assumption conclude that I can infer information about the properties of objects from my experiences. I do not infer that I can infer the properties. That doesn't make any sense.

These experiences are brain processes just like the brain processes that are the experience of colour.

What experiences?

Once again, you are all mixed up. Color is one of many brain processes that extract information about objects from. Objective qualities are not brain processes. They are not experiences.
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I know what your position means. Don't waste your time repeating your assumptions. I'm trying to address some inconsistencies. You infer objective qualities like length from your experiences, which you say are brain processes. You say colour is a brain process, but you do not infer an objective quality from that experience.

Of course I do! Color is one of the experiences that I use to infer objective qualities like the range of wavelengths reflected by an object, then wavelengths of light impacting the object, and a number of other objective qualities. As always, context is important.

Where on Earth did you get the idea that I do not infer objective qualities of objects from my experience of seeing color?

I know what your position is !!! What about the point I am actually bringing up ? Can you address it please ?

If the experiences you use to infer your objective "length" are themselves brain processes and colour is also a brain process then why do you infer length but not colour for objective properties ?

What?? I do infer objective properties from my experiences of color.

Stimpy: I don't. There are no brain processes which constitute the length of an object. That is an incredibly silly misrepresentation of my position.
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And that is an incredible misrepresentation of my question. You know what I mean. Just start addressing the question will you please ?

No, I don't know what you mean. Your questions do not appear to have any relevance to my position. You claim to understand my position, but you clearly do not.

How do you justify inferring objective properties of objects from some experiences and not others ? Your justification for not inferring colour to be an objective property of an object is to simply state that it is a brain process. However, you also say that the experiences you use to infer length as an objective property of an object are also brain processes. Why do you infer from some brain processes and not others ?

So long as you are talking about experiences which result from sensory input, I don't. Where did you get the idea that I do?


Suggestologist,

Information processing. Computation. Retrieval and storage of memory. All sorts of things going on subconsciously, which you are not aware of, and can therefore not reasonably be said to have "experienced".
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I completely agree. But, are you saying that objectivity comes from the subconscious? Since consciousness produces subjectivity, then subconsciousness produces objectivity? You probably don't mean that.

No, I didn't mean that, and I am stupefied as to how you could possibly interpret what I said to mean that.

Not true. They are not experiencable by anybody else. That does not mean that they are undetectable, or non-objective, or in any other way fundamentally different from any other physical process.
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Sure, perhaps one day computers will be able to read people's thought processes and detect which emotions, thoughts, and memories are progressively triggered during such experiences.

Someone still has to verify this through personal experience, and it probably has to be the person being mind-probed.

Not necessarily. And even if that does turn out to be the case, things like double-blinding can be used to eliminate subjective bias. Either way, there is nothing "irreducibly subjective" about it.

Sure, they are subjective. That does not mean that they do not objectively exist, or that they are not physical processes, or that they cannot be studied and understood scientifically.

And once again, this has no relevence to the topic being discussed, which is whether or not your sensory experiences are qualities of the objects you are percieving.
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Nice relevancy challenge. Whether or not sensory experience EQUALS qualities of the objects -- has no clear meaning as a question. It's not well-formed. The correct answer is: What do you mean?

Obviously. But that is exactly the question which was asked at the beginning of this thread.

Pragmatism. If we don't make that assumption, then we have nop source of information about objective reality.
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You have to admit, that's circular. Of course, circular reasoning isn't always a logical fallacy. But one has to show that it isn't.

It is an axiom. Axioms cannot be proven. I am not attempting to prove it is true. I am offering a justification for why I choose that particular axiom.

It's sort of like saying: If there's no god, then existence is meaningless; therefore we must postulate a god or things would be horrible, blah blah blah.

The problem with that line of reasoning is not that it is circular, but that it is itself based on the false assumption that simply assuming God exists gives meaning to existence, and that no other philosophical framework can do so. That, and the fact that it does not form part of a falsifiable framework which can then be tested, in order to get evidence (not proof) supporting it.

I said using the principles of science. Double blind studies are a very effective way of controlling for subjective bias, but not the only way. in any event, the double blind protocal is not even relevent to the above scenario.
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I agree. There are people who claim to understand science, however, they bandy about techniques that don't apply to a particular experiment. I won't mention any names yet. In order to understand which techniques do apply, you must understand the particular subject of investigation, not just the "scientific method".

What's your point?

Do you actually have any idea what you are talking about at all? Or are you just repeating the post-modernistic nonsense that you heard from somebody else, or read about in some philosophy book or papers?

Dr. Stupid
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The guidelines for publication? What good are those when the referees don't critically analyze the papers? This is all within the social reality of the publication process of scientific papers.

Translation: No.


Dr. Stupid

 

[Interesting Ian]

I have already explained why this is the case. It is because color and smell are experiences we have, and length is a property of an object which we do not experience at all, but instead assign to the object based on logical inferences from our experiences.

Why is that so difficult to understand?

You've stated that you mean by inference that you can measure length. But obviously one can also measure colour. So what is the distinction?

 

[Mercutio]

You've stated that you mean by inference that you can measure length. But obviously one can also measure colour. So what is the distinction?

We don't actually measure color, we measure wavelength, intensity, and saturation. Each of those is a physical correlate of our perceptual experience of color. The big difference is that we experience color, but not length. Including wavelength--we do not directly experience wavelength, but infer it from our experience with measuring devices.

On a separate (sorta) topic, I have a question for you, Ian, which I have tried to figure out from your point of view and have failed. I have seen samples of paint chips (actually, any number of visual perception books can give you the proper examples, as can some books on interior decorating) that look absolutely identical under incandescent light--you simply cannot tell them apart. Squint, put different surrounds on them, hold them closer to the light--they are, it appears, identical. Then, turn on a fluorescent light. Suddenly the two paint samples are shockingly mis-matched (which is why the interior decorating book talks about it--you wouldn't choose a paint under one light that you plan to use with another light), because the light that hits your retina (in the standard explanation) depends not only on the object (the paint chips) but also on the wavelengths of the light shining on it. It is almost exactly the counter-example to your car example on the last page. If you are seeing the qualities of the object itself, why such different experiences based on the two lights?

 

[Interesting Ian]

We don't actually measure color, we measure wavelength, intensity, and saturation.

That is what scientists define as colour isn't it? You seem to be saying here that we don't measure the qualia of colour. Well obviously, but then we don't measure the qualia of length either! So what is your point?

Each of those is a physical correlate of our perceptual experience of color. The big difference is that we experience color, but not length.

We do not experience length?? What? We don't have certain perceptual expereinces of a certain length of something?? This seems to me to be obviously false. You'd need to explain yourself here. I mean I experience my mouse as being of a certain length. I could also measure it. Same for its colour. I experience it as being a certain colour. One could also theoretically measure its colour. So what's the distinction?

 

[davidsmith73]

Stimpy,

I'm going to go back a bit here and start with what I think your position with regards to primary and secondary qualities is.

You think that this distinction is a mistake. There are no secondary qualities of objects such as redness or fart smell. These are merely brain processes. The experience of red is not a property of an object. It is just a brain process.

You also say that the experiences that you use to infer the primary qualities of objects such as length, mass, velocity etc, are also not the properties of the object but just brain processes. For example if you hold a ball, there is the experience of subjective weight and there is an inferred property of the ball which we call its weight. These are separate things but we do not experience the latter.

So you have the situation whereby you are inferring properties of objects from some experiences but not others. This brings us to your assumptions about reality. Your assumptions about reality are that it is more than just your experiences, logical and consistent. You say this forms a falsifiable framework. This framework would be falsified if you were to experience something other than what is predicted by it. (I'm still not sure what observations would constitute falsification - perhaps you can tell me)

The experiences you use to infer the objective properties of objects is thus based on their agreement with your framework. In other words they have logical relationships and are consistent.

So here's my first worry:

You say experiences such as redness are not objective properties of objects because they are just brain processes.

However, you say that properties of objects can be inferred from brain processes.

So my first question is, why do not infer objective properties of objects from brain processes such as redness ?

 

[Mercutio]

That is what scientists define as colour isn't it? You seem to be saying here that we don't measure the qualia of colour. Well obviously, but then we don't measure the qualia of length either! So what is your point?

Actually, no, that is not what scientists define as colour. Color itself is a private experience, and is not measureable. (well...we can, through color-matching procedures, make some inferences about your perception of color--by looking at how you match a single wavelength with a combination of two other wavelengths, but this relies only on your verbal report about your private behavior of seeing color). As for "the qualia of color", the phrase is redundant. Color is not measured, it is experienced--which, I gather, is the definition (at least practically) of qualia. As for a qualia of length, perhaps you could give me an example; I can experience looking at something, but I infer its length (after some learning) from its visual angle and presumptions about its distance from me. I can experience touching something, but I infer its length from proprioceptive feedback about how far apart my fingers or arms are (I may experience touching a plank with both hands, but I infer its length, with experience, from how far apart my arms are). Unless you can give me some specific instance in which we experience length (hmm...from a materialist view, where are the length-receptors?), I still don't see it.

We do not experience length?? What? We don't have certain perceptual expereinces of a certain length of something?? This seems to me to be obviously false. You'd need to explain yourself here. I mean I experience my mouse as being of a certain length. I could also measure it. Same for its colour. I experience it as being a certain colour. One could also theoretically measure its colour. So what's the distinction?

See above...you experience your mouse as touching your hand in particular places, and from this you infer its length. Its length is not directly experienced. Of course, you have been doing this sort of inference for decades, so it is essentially automatic--it is really tough to de-automatize it.

 

[Interesting Ian]

I'm sorry but I do not believe that colour (as understood scientifically) cannot be measured. As far as I'm concerned it is a particular wavelength of electromagnetic radiation reflected off an object. Your assertion that it cannot be measured is absurd.

 

[Mercutio]

That is what scientists define as colour isn't it? You seem to be saying here that we don't measure the qualia of colour. Well obviously, but then we don't measure the qualia of length either! So what is your point?

later..

I'm sorry but I do not believe that colour (as understood scientifically) cannot be measured. As far as I'm concerned it is a particular wavelength of electromagnetic radiation reflected off an object. Your assertion that it cannot be measured is absurd.

G.T. Fechner's great discovery of "how to study sensation & perception", leading to the founding of psychophysics as a science, grew from the inability of any of us to measure private experience (visual perception in particular, for Fechner). His solution was to forget about trying to measure experience, but rather to measure the stimulus events, and ask subjects whether or not they could detect changes between different stimuli. When we look at colour perception, for instance, we do not, and cannot, measure color as perceived. What we can do is to measure the wavelength, intensity and saturation of a visual stimulus and see how that correlates to your experience. Using Fechner's methods, we can find absolute thresholds (the smallest stimuli detectable) and difference thresholds (smallest detectable changes in stimuli) for wavelength, for intensity (experienced as brightness), for saturation (experienced as chroma--how faded or clear a color is). We can do this for our other senses as well, but your question was about color vision.

With our accumulation of information about visual systems, we can now, for instance, map out the concentration of alpha, beta and gamma photopigments in your retina, measure the density of the macular pigment of your eye, and then (just for instance) make a prediction about what combination of two different wavelengths will be perceived as identical to a given single wavelength. In short, we are predicting your color experience from other, measurable aspects of your visual system.

Now, if I am not mistaken, the subjective view (I don't know what else to call it--I don't like the label...maybe antimaterialist is better, I don't know...just pretend I called it the right thing) does not predict this. It does not preclude it, either, admittedly, but as far as I can tell it does not predict that a particular physical setup should lead to a particular perception (If I am wrong about this just let me know--I don't claim to be an expert in that worldview).

(edited to highlight a portion)

 

[Interesting Ian]

As for a qualia of length, perhaps you could give me an example; I can experience looking at something, but I infer its length (after some learning) from its visual angle and presumptions about its distance from me.

This inference being what Dymanic referred to as intrinsic inference rather than logical inference. You don't really work out its length from visual angles and its apparent distance away. The length is just immediately seen. You might say it is "inferred" from context.

 

[Interesting Ian]

If we cannot measure colour, then one cannot measure the length of ones willy!

 

[Mercutio]

This inference being what Dymanic referred to as intrinsic inference rather than logical inference. You don't really work out its length from visual angles and its apparent distance away. The length is just immediately seen. You might say it is "inferred" from context.

You yourself, in another thread on this forum, discussed the "carpenter world" hypothesis--the idea that some visual illusions are the result of learning within a specific environment. THe classic example is of the person who does not recognize perspective in a photograph, thinking an elephant at a distance is the same size as the person in the foreground. As I said above, you have been making these "immediate inferences" for decades, so they are essentially "immediately seen", as you say. You are quite correct to say that we do not "work out" its length using some geometric calculus...but even if it is intrinsically infered, it is not directly perceived. If we do not learn to make that connection, we will not make that connection. (there is evidence, not that I am familiar enough with it to use it, from cases of blind individuals having their sight restored. Size and distance of objects is a huge problem for them--they have to learn the connections between their visual sensations and their tactile, proprioceptive, and hearing.)

 

[Mercutio]

If we cannot measure colour, then one cannot measure the length of ones willy!

There's a joke here about "what does the color of one's willy have to do with its length?", but I am not going to be the one to make it...

 

[Interesting Ian]

There's a joke here about "what does the color of one's willy have to do with its length?", but I am not going to be the one to make it...

Do you agree that if we cannot measure colour then similarly we cannot measure length? If not then why not? I fail to see the distinction. Indeed this is the question my opening post was about!

 

[Interesting Ian]

You yourself, in another thread on this forum, discussed the "carpenter world" hypothesis--the idea that some visual illusions are the result of learning within a specific environment. THe classic example is of the person who does not recognize perspective in a photograph, thinking an elephant at a distance is the same size as the person in the foreground. As I said above, you have been making these "immediate inferences" for decades, so they are essentially "immediately seen", as you say. You are quite correct to say that we do not "work out" its length using some geometric calculus...but even if it is intrinsically infered, it is not directly perceived. If we do not learn to make that connection, we will not make that connection. (there is evidence, not that I am familiar enough with it to use it, from cases of blind individuals having their sight restored. Size and distance of objects is a huge problem for them--they have to learn the connections between their visual sensations and their tactile, proprioceptive, and hearing.)

People who are congenitally blind and who have their sight restored may henceforth "enjoy" perfect vision, but they cannot see. They have to learn to see. If shown a cube and a sphere on first getting their vision, they would not be able to tell which is which purely from their vision, even though they may have felt these objects on many an occasion in their blind state!

And if intrinsic inference is not directly seeing then "directly seeing" is vacuous.

 

[Stimpson J. Cat]

Ian,

You've stated that you mean by inference that you can measure length. But obviously one can also measure colour. So what is the distinction?

I can measure the wavelengths of light given off by an object. That is a property of the object. We often call that "color". We also often refer to the experience of color that we have when we look at the object as "color". That is not a property of the object.

I'm sorry but I do not believe that colour (as understood scientifically) cannot be measured. As far as I'm concerned it is a particular wavelength of electromagnetic radiation reflected off an object. Your assertion that it cannot be measured is absurd.

You are deliberately misrepresenting what both Mercurtio and I have said. We have both clarified as precisely as possible the distinction between the experience of color (which is a brain process), and the property of color (which is an objective characteristic of the object).

Nobody is claiming that the wavelength of light reflected off of an object cannot be measured, and you know it.

If we cannot measure colour, then one cannot measure the length of ones willy!

Nobody is claiming that the length of an object cannot be measured, nor that the wavelength of light emitted cannot be measured. Enough with the stupid strawman arguments already!

Do you agree that if we cannot measure colour then similarly we cannot measure length? If not then why not? I fail to see the distinction. Indeed this is the question my opening post was about!

If you define color as the wavelength of light reflected, then we can measure both. This has nothing to do with the question in your opening post, because both of these things are, within the context of that question, "primary qualities".

Please stop trying to deliberately confuse the issue.


Dr. Stupid

 

[Stimpson J. Cat]

davidsmith,

I'm going to go back a bit here and start with what I think your position with regards to primary and secondary qualities is.

You think that this distinction is a mistake. There are no secondary qualities of objects such as redness or fart smell. These are merely brain processes. The experience of red is not a property of an object. It is just a brain process.

You also say that the experiences that you use to infer the primary qualities of objects such as length, mass, velocity etc, are also not the properties of the object but just brain processes. For example if you hold a ball, there is the experience of subjective weight and there is an inferred property of the ball which we call its weight. These are separate things but we do not experience the latter.

OK so far.

So you have the situation whereby you are inferring properties of objects from some experiences but not others.

What do you mean?

This brings us to your assumptions about reality. Your assumptions about reality are that it is more than just your experiences, logical and consistent.

You missed one: That our experiences contain information about this reality, which can be extracted through various methods of empirical verification.

You say this forms a falsifiable framework. This framework would be falsified if you were to experience something other than what is predicted by it. (I'm still not sure what observations would constitute falsification - perhaps you can tell me)

Imagine a world where nothing makes any sense. Where the apparent rules of the world seem to change from one moment to the next, or where no rules can be discerned at all. We do not appear to live in such a world. The assumptions I listed are the minimum assumptions necessary to predict that when I wake up tomorrow, I will not be in such a world.

The experiences you use to infer the objective properties of objects is thus based on their agreement with your framework. In other words they have logical relationships and are consistent.

You seem to be suggesting that I simply discard any experiences which "don't fit". This is not true. Just because I do not draw conclusions about objects in space around me from some of my visual experiences, does not mean that I simply discard them without any consideration at all. It just means that I have inferred that they are artifacts of my imperfect visual system, rather than experiences which contain useful information about by surroundings.

If we had no understanding of things like optical illusions and hallucinations, then maybe your idea would have some merit, but this is not the case. We understand a great deal about how sensory perception works, and that information plays a role in how we infer things about the objective world from our experiences.

So here's my first worry:

You say experiences such as redness are not objective properties of objects because they are just brain processes.

However, you say that properties of objects can be inferred from brain processes.

So my first question is, why do not infer objective properties of objects from brain processes such as redness ?

I do. I told you this before. This is trivially obvious. When I look at an apple, and experience redness, I infer that the apple is reflecting certain wavelengths of light. That inference is made from the experience of redness, along with other factors (context).

Where on Earth did you get the idea that I do not?


Dr. Stupid

 

[Mercutio]

People who are congenitally blind and who have their sight restored may henceforth "enjoy" perfect vision, but they cannot see. They have to learn to see. If shown a cube and a sphere on first getting their vision, they would not be able to tell which is which purely from their vision, even though they may have felt these objects on many an occasion in their blind state!

And if intrinsic inference is not directly seeing then "directly seeing" is vacuous.

This is precisely the distinction I wished to make. Your first paragraph illustrates exactly the difference between the experienced and the inferred. The newly-sighted person does have visual stimuli pouring in--these are directly experienced. They are also, as you correctly point out, essentially meaningless to the person, until they learn to correlate the visual information with other information (tactile, proprioceptive, and remembered information) about the world. They must then learn to infer the length of seen objects, because they cannot directly experience it. They do not have to learn to see yellow. (they must, however, learn to label it appropriately and to discriminate it from other colors. ) They must learn to infer distances (in complete agreement with your other-thread carpenter-world example). They even need to learn which lines and blobs go together (the gestalt perceptual rules discussed earlier in the thread). It is even possible that there are "sensitive periods" or even "critical periods" developmentally that this person will have skipped, making some types of perceptual learning impossible. (There are experiments with fish, and with cats--probably some others--that illustrate that if you are brought up in an environment with no horizontal lines, for instance, you will not develop the feature-detector cells that signal "horizontal")

As for your second paragraph, I am sorely tempted to agree with you...but alas, cannot. "Directly seeing", in this context, is quite limited, as a practical tool. It is the raw data, unprocessed, from which we interpret and infer the world around us. But it is there, and it is different from the inferred in important and meaninful ways. So, "vacuous" I cannot quite agree with.

 

[Mercutio]

I must point out that a collective cannot have an experience; only the individual members of the collective can have individual experiences. The things they trust each other to experience (and assign meaning) in ways similar to how they themselves experience (and assign meaning to) that same thing -- is a collection of social truths -- the social reality.

...snip...

I did not mean to suggest that there are different "types" of experience. There is only one "type" of experience, and it is a private one. No matter how you attempt to communicate it to someone else, the communication will ALWAYS be incomplete. When someone communicates their experience or a social truth to you, you experience it just like any experience -- privately. But you cannot, ever, hope to fill in all the gaps that would make second-hand experience (the reconstruction in your mind) as complete as primary-experience (experiencing the event for yourself). Necessarily then, personal experience is more complete than a communicated experience can ever be. And communicated experiences are also prone to deliberate and accidental error -- noise in the information, if you like. Copies usually have more noise than originals. So one cannot be as certain about communicated second-hand experience, as of personal first-hand experience to represent the physical reality -- that which has a meaning that cannot be negotiated among humans.

Am I mistaken, or is your view as expressed here reducible to solipsism?

 

[Interesting Ian]

Ian,



I can measure the wavelengths of light given off by an object. That is a property of the object. We often call that "color". We also often refer to the experience of color that we have when we look at the object as "color". That is not a property of the object.

Right, so analogically speaking, if one measures ones willy that is a property of that object ie the "length" of the willy. Now when we experience a colour it is of a certain shape and length, is it not? Therefore if we say we experience colour we cannot at the same time deny we experience length. Right? But nevertheless this experienced length is not a property of the object but rather a physical process in the brain (it must be if the experienced colour is).

You are deliberately misrepresenting what both Mercurtio and I have said. We have both clarified as precisely as possible the distinction between the experience of color (which is a brain process), and the property of color (which is an objective characteristic of the object).

I understand perfectly. And we must say precisely the same about length. Therefore your distinction between length and colour is spurious.