Perception and the Physical World

[Pythagorean]

The doctrine of naïve realism is a common sense doctrine which postulates at least two things:

1) The things in the physical world that we see and touch (or perceive in any other way) also exist when they are not being seen or touched or perceived. That is, things continue to exist in the same way even when we are not immediately aware of the things.

2) Naïve realists further take it for granted that things simply posess just those qualities that they appear to posess.

Many philosophers have taken issue with this second postulate by claiming that it involves a patent contradiction. For example: a penny when viewed from directly above appears circular; and the same exact penny when viewed from a side angle appears elliptical.

Also a stick when part of it is held under clear water appears bent. When we look at the stick in water are we looking at the real stick?

And also the same volume of water under certain conditions can feel cold to one hand and warm to the other hand.

Furthermore, how can colour be a quality "in" objects which themselves appear to be coloured in different ways, considering that the apparent colour of things varies with conditions of illumination as well as organic conditions (consider "jaundice", for example)?

The questions some philosphers have asked are: do we ever truly see a "physical penny" in itself at all? Do we ever really see a "physical stick" in itself at all?


So, what would a completely objective view of physical objects (a 'god's eye' view) look like? Can we have a true perception of objects?

The philosopher John Locke has maintaied that since qualties such as colour and temperature are dependent upon the subjective observer then physical objects do not posess these qualities of colour and temperature. He states that since physical objects in themselves (i.e. when they are not being perceived) have neither colour nor temperature, then what we perceive are ideas (sense data, or percepts) and not the physical objects themselves.

And whether or not our ideas (our sense data) of physical objects are said to actually correspond to those objects, they are, claims Locke, seperate and distinct from the physical objects. Locke is saying that what we perceive in our sense data is not the same as what real objects posess. Locke's theory is called representational realism also known as The Veil of Perception.

It was Kant who said that we can know nothing of things as they are in themselves. He said that we cannot have knowledge of things as they exists when we are not perceiving them. Kant says that we can only know the 'appearances' of things which he called 'phenomena". Kant says that since an object is distinguished by the time under which it is observed and the space in which the act of observations takes place, then the true nature of an object must exist only by abstracting the object from time and space, which is impossible for man to do.

Kant says that humans 'create' the categories of time and space and thereby falsify objects; since the true nature of the object in itself is bound up with universal causation. To perceive an object then is to falsely 'remove' it or seperate it from its millenial cosmic path of becoming in time and its necessary supporting materials in space.

[kennethamy]

Originally Posted by Pythagorean

The doctrine of naïve realism is a common sense doctrine which postulates at least two things:



2) Naïve realists further take it for granted that things simply posess just those qualities that they appear to posess.

.

I just wonder who these naive realists are. I don't think that when I am on top of a tall building, that the people I see below me are as small as ants, although they look that small. And I don't think that a when I see a stick half-way immersed in water, that it really is a bent stick. And I don't think that when I see an object in near-darkness, that is doesn't have a color. And I don't know anyone who does. Do you? Everyone I know, except maybe for little babies, make adjustments for the conditions under which they perceive objects.

[Fido]

The first part of the definition of realists suggests the principal of identity and conservation. The second part is just naive. Sure, we perceive things as they seem until we know better, but then we perceive with our minds where knowledge overrules appearance.

Locke is right that objects do not have color. Light has colors. Trees are green because they absorb all bandwidths except green, which they find useless. What we enjoy about living vegitation is vegitable trash. The same is true of temperature. Objects absorb heat, and radiate heat, but few are warm on their own unless their nature is a state of chemical reaction, as in rotting vegitation.

Kant is right in most respects. Wrong about space and time. We do not create them, but rather give them meaning. They are both non existent unless we perceive that to be understood, all things must exist in the context of time and space. To 'Know' something is to be able to place it in its context, to classify it both in time and space, and also as to catagory. The concept, or the idea, or the form represent reality as knowledge. And all concepts are conserved qualities that take for granted that nothing changes within our sight or out of our sight without another force acting upon it. It would be impossible for anyone to learn without some notion of conservation. Not even a child believes that when his mother is out of the room that she becomes something other, and when his mother returns he does not presume it is one of an infinite number of identical mothers waiting outside his door. Actual knowledge rests upon relatively few conserved qualities, but time changes all, or more correctly, all change in time, which gives time a constant reference in all things like the seasons which are cyclical.

[Pythagorean]

Fido,

Excellent post! Thank you for pointing out especially that most things do not generate their own source of heat. That was an astute observation on your part and one which I was not even thinking about.

Excellent analysis but what about time as viewed from a longer term, more cosmological perspective. It takes so many millions of years for a galaxy to form, for example. I was wondering what happens to your analysis of time and conservation if we were to look at the surface of the earth replacing minutes and hours with centuries? In this case the conserved ideas, forms or concepts are replaced with processes or matrices of ebb and flow. Maybe man must become more detached from the immediate world of nature in order to make the best objective evaluations?

But I think, if I am not mistaken, that is exactly what Kant is saying: The human understanding interferes with the processes of nature in order to procure for himself some knowledge. By giving local meanings (as you say), to time and space we disturb the inherent relations of the objects of knowledge whose relations are naturally intertwined and connected within broader cosmological considerations of causation which we do not have access to as yet. But perhaps there is a perspective that is possible that is outside of time? A perspective which knows the fundamental laws of physical reality and can 'see itself seeing itself' which can take the subjective aspects of time and space measurement into consideration and objectify everything including the observer himself? Maybe we can classify things without time?

I mean, we can't say we know one link in a chain because the one link has been artifically seperated from the great chain of being by us; but maybe if we went deep into the wilderness for example and sat down and meditated and forgot about the ego for a while and became part of the wilderness itself, then maybe we wouldn't be artifically seperate. This is something that I have been considering.

So I don't think you have proven to me that Kant was wrong by saying that we create time and space but you have surely enriched my thinking on the matter! You have further inspired me, Fido to think this through even more elaborately!

--Pyth

[Pythagorean]

kenneth,

Common sense realism i.e. naive realism is simply an unreflective, un-philosophical acceptance of the physical world as it appears to primitive men the nature of which is superficiality.

Is the shape of the penny circular or is it elliptical? OF course under a microscope a penny is neither circular nor elliptical but all across in every direction is rather bumpy like holey mountain ranges!

[kennethamy]

Originally Posted by Fido

T

Locke is right that objects do not have color. Light has colors. Trees are green because they absorb all bandwidths except green, which they find useless.

But I don't understand why that shows that objects have no color. What that is explains why objects have color. After all, not only are objects green because of the explanation you give, but also, because human beings have the perceptual faculties that they have. To say that a leaf is green is to say that under normal perceptual conditions, the normal observer will see a green leaf. That does not mean that leaves are not green. Rather it tells us what it means to say that a leaf is green. You don't want to say that when leaves are seen at night when there is no light that leaves are no longer green, do you?

Locke did not say that leaves are not green. He said that color is a secondary property. That is very different.

[kennethamy]

Originally Posted by Pythagorean

kenneth,

Common sense realism i.e. naive realism is simply an unreflective, un-philosophical acceptance of the physical world as it appears to primitive men the nature of which is superficiality.

Is the shape of the penny circular or is it elliptical? OF course under a microscope a penny is neither circular nor elliptical but all across in every direction is rather bumpy like holey mountain ranges!

Pennies are circular, obviously. You seem to be assuming that unless a penny always appears to have the shape it actually has under all conditions of perception it has no shape. But that is absurd. The penny does have a shape. And it is the shape it appears to have under normal conditions of perception. Namely circular. The fact that a penny looks bumpy etc. has nothing to do with its shape. It can be bumpy, and still circular. Circular object may still be bumpy. The moon is quite bumpy. But it is accurate to describe it as circular, as contrasted (say) with triangular, or trapezoidal. Circular in shape does not mean, circular with no bumps.

[Fido]

Originally Posted by kennethamy

But I don't understand why that shows that objects have no color. What that is explains why objects have color. After all, not only are objects green because of the explanation you give, but also, because human beings have the perceptual faculties that they have. To say that a leaf is green is to say that under normal perceptual conditions, the normal observer will see a green leaf. That does not mean that leaves are not green. Rather it tells us what it means to say that a leaf is green. You don't want to say that when leaves are seen at night when there is no light that leaves are no longer green, do you?

Locke did not say that leaves are not green. He said that color is a secondary property. That is very different.

Color is a property of light, and not of things. Matter absorbs radiation, and what we see is what it cannot absorb. If it is a property of anything it is of the chemical structures in the matter. It is just easier to say a thing is green than to say why it appears green. It is not green, but its green color is a negative quality. Am I correct in saying that the colors it absorbs reflect its chemistry but the colors it reflects does not since many things appear green for different reason, that is, not the same chemical makeup? I do not know if it is true in either case. Things are green which appear green, but its greeness tells us very little after all. Emiting of light at a certain bandwidth is an atomic property, of bosons I believe. Colors do tell us something of atomic structure.

I think your point is wrong about things being green because of perception. First of all, it is not a tree falling in the forest. It reflects light when is gets light. But the light it reflects has an essential relationship to the light it absorbs. A plant does not see as we see, but in the sense that it follows the sun, uses all it can of the energy of the sun and then emits not only the most useless color to it, but to all other plants, and shades those beneith, in that sense I can say it sees light as well as us. It is not perception that makes things real, but our perception that gives them meaning. If there were no humans to sense time, space, color, or any other attribute of reality, it would still be there; but it would have no meaning. Life gives all reality meaning.

[kennethamy]

Originally Posted by Fido

Color is a property of light, and not of things. Matter absorbs radiation, and what we see is what it cannot absorb. If it is a property of anything it is of the chemical structures in the matter. It is just easier to say a thing is green than to say why it appears green. It is not green, but its green color is a negative quality. Am I correct in saying that the colors it absorbs reflect its chemistry but the colors it reflects does not since many things appear green for different reason, that is, not the same chemical makeup? I do not know if it is true in either case. Things are green which appear green, but its greeness tells us very little after all. Emiting of light at a certain bandwidth is an atomic property, of bosons I believe. Colors do tell us something of atomic structure.

I think your point is wrong about things being green because of perception. First of all, it is not a tree falling in the forest. It reflects light when is gets light. But the light it reflects has an essential relationship to the light it absorbs. A plant does not see as we see, but in the sense that it follows the sun, uses all it can of the energy of the sun and then emits not only the most useless color to it, but to all other plants, and shades those beneith, in that sense I can say it sees light as well as us. It is not perception that makes things real, but our perception that gives them meaning. If there were no humans to sense time, space, color, or any other attribute of reality, it would still be there; but it would have no meaning. Life gives all reality meaning.

Do you really mean that leaves are not green in the summertime? I didn't say they were "green because of perception". In fact, I don't really know what that means. I said that they were green, and that what was meant by saying that leaves are green is that leaves appear green to the normal observer under normal conditions. So, to say that leaves have some mass is not to say that leaves appear to have weight to the normal observer under normal conditions, but (to repeat) to say that leaves are green is to say that they appear green to the normal observer under normal conditions. So we are distinguishing between two different kinds of property of leaves: secondary, and primary. But John Locke never said that objects have not color. What he did was to explain how it is that objects have color.

[Fido]

Originally Posted by kennethamy

Pennies are circular, obviously. You seem to be assuming that unless a penny always appears to have the shape it actually has under all conditions of perception it has no shape. But that is absurd. The penny does have a shape. And it is the shape it appears to have under normal conditions of perception. Namely circular. The fact that a penny looks bumpy etc. has nothing to do with its shape. It can be bumpy, and still circular. Circular object may still be bumpy. The moon is quite bumpy. But it is accurate to describe it as circular, as contrasted (say) with triangular, or trapezoidal. Circular in shape does not mean, circular with no bumps.

Part of the difficulty lies as always with the truth, which is how we fairly represent reality. If you are using a descriptor, what is it good for? My example for this is quite common: The uterus is a pear shaped organ. So what is a pear? A uterus shaped fruit? There is nothing like the other except the earth, which is slightly pear shaped. Or is that uterus shaped? We try to tell the truth about reality. We should try to understand that knowledge color perception. When we know why reality seems as it does we see reality in a different light. And perspective colors perception. Not one thing on this earth will ever apppear the same to two people.