Knowledge begins with consciousness. I do not mean that consciousness is itself knowledge, but that if we are to know anything we must first be conscious of it. It is not enough just to be conscious, however, if it is to be capable of providing us knowledge. If what we are conscious of is not totally reliable and valid, no knowledge is possible.
The history of philosophy is largely the history of an assault on the validity of reason and knowledge. One of the earliest of those assaults was Plato's assault on the validity of perception. If what is perceived is itself deceptive, all knowledge based on it must be deceptive as well. Other varieties of the assault were made by Hume and Kant and almost without exception, all philosophers have accepted the repudiation of the validity of perception in some form.
There is no basis for that repudiation in the form or evidence or reason, but, unfortunately, the few philosophers who have attempted to defend the reliability of perceptual evidence have botched the job.
Perception Is Consciousness
Human consciousness is sometimes described as having three levels or aspects designated as sensation, perception, and conception. This view supposes that we are first conscious of sensations provided by the sensory nervous system, which are processed by the brain into percepts of things, which in human beings are identified and reasoned about at the conceptual level. Nothing is conscious of anything called sensations or sense-data. The only consciousness humans or any other creatures have is perception. There is no "conceptual level" of consciousness. Human perception is unique in that it is volitional, which makes the conscious mind possible, an attribute of consciousness no animal has. If that is all that was meant by "conception" it would be acceptable, but it is not a unique kind of consciousness.
What Is Consciousness
Consciousness is perception. It is the direct awareness of "percepts" or all that one sees, hears, smells, tastes, and feels, provided by the external sensory nervous system as well as all one is directly aware of as feeling and emotions including hunger, vertigo, nausea, fear, etc. which is called interoception provided primarily by the limbic system, as well as percepts provided to consciousness from memory. (Some percepts like those derived from external sensory nervous system are mistakenly called "senses.")
[NOTE: Where we are going. Everything that exists has a specific identity and that identity is all its qualities and attributes. To be conscious of anything it is a thing's attributes one must be conscious of, because its attributes are what it is. Not all of a thing's attributes are available to consciousness, only those attributes which can be directly perceived, but it is by means of those attributes that all of any existents attributes are discovered.]
What Are Percepts
Percepts are what we are directly conscious of by means of perceptual qualities. The perceptual qualities are direct consciousness of the attributes of whatever is being perceived by means of the sensory nervous system. The perceptual qualities include: visually; color, hue, intensity; audibly: pitch, loudness, tactilely: pressure, temperature, pain; olfactorily: scent; gustatorialy: taste, internally: comfort, desire, hunger, vertigo, fear, etc.
Conscious perception is direct conscious awareness of all that can be perceived by means of the perceptual qualities.
Once it is understood explicitly, that an entity's identity is its qualities (characteristics and attributes), it is obvious, to perceive an entity, it is it's perceivable qualities that must be perceived.
Only those qualities of an entity available to the senses will be perceived of course, but it is entities, as they are perceived, that are real existents. All other attributes of existents are discovered conceptually, not perceptually.
Entities are whatever their qualities determine they are, and whatever an entity is, determines what its qualities are. To be perceived, it is an entity's qualities that must be perceived, and that is exactly what is perceived. When an entity's qualities are perceived, the entity itself is perceived, because an entity's qualities are what it is.
More importantly, the ontological insight validates perception. If existents are whatever their qualities are and it is their qualities that are perceived, it is actual existents as they actually exist that are being perceived. Though only the perceivable qualities of existents are available to consciousness, ontologically, all of an existent's qualities are implied by its perceivable qualities.
Perception and the Neurological System
It is not within the province of philosophy to discover and describe how the physical neurological system works. It is within the province of philosophy to describe what it must do if perception is to be valid. The following is a general description of the function of a neurological system that provides valid perception.
The neurological system, which includes the sense organs, both internal and external, as well as the entire nervous system and brain, is the means of providing to consciousness all those qualities and attributes of reality that can be perceived in their exact total context, including the state and nature of the perceiver.
This system makes available to consciousness everything pertinent to the organism that is in any way physically related to it. The "system" presents to consciousness the light that is reaching the eyes, how and where anything is touching the organism, the sound that is reaching the ears, the chemicals in the air it is breathing, and those in whatever substances it puts into its mouth, as well as its internal physiological states; and it does this continuously. The level of sophistication of the perceptual system is determined by the sophistication of the organism.
Obviously, that which is presented to consciousness for which the eyes are the source are the percepts of color, intensity, and the behavior of the eyes themselves perceived as stereoscopic phenomena (depth perception); that which is presented to consciousness for which the ears are the source are the percepts of sound; that which is presented to consciousness for which the sensory nerves are the source are the percepts of touch, temperature, and pressure; that which is presented to the consciousness for which the olfactory nerves or taste buds are the source are the percepts of scent and taste, that which is present to the consciousness for which the internal senses are the source include everything from our sense of balance to hunger, as well as the emotions.
These are not presented to consciousness willy-nilly, so-to-speak, but organized by source and in the exact way and order they are derived. The eyes focus the light reaching them into an image, and the light and color components of that image are detected by the rods and cones of the retina, and that detected information is transmitted to the brain where the response of the brain to the action of those nerves is consciously perceived as the percepts of color and light that we call "seeing."
The Function of the Perceptual System
The perceptual system provides immediate awareness of the entire field of perceptual qualities available from all the sense organs at every moment as consciousness. The field of direct perceptual consciousness (as opposed to that derived from memory) is all the perceptual qualities available from all the sense organs in the exact arrangement they are detected.
Perception, in function, is analogous to television. A television camera captures everything in its field of view, exactly as it is, without discrimination or organization. If that field includes people, objects, animals, and background, for example, they will all be captured. But they are not captured as individual entities and background. What is actually captured is the color and intensity of the light being reflected from every point in the scene. An object, for example, is not captured as an object, but as a collection of colored points within the whole field of colored points currently being recorded by the camera.
When the image is displayed on a TV, there is no special, "organization," or "integration," of the electronic data to "separate" and "make visible" entities in the image. The TV merely presents all the captured points of light in the exact order in which they are captured. Those that make up objects, are objects in the image, those that make up people, are people in the image. Nothing special has to be done to make them appear as objects or people or to separate them from the background.
The captured points of light represent the visible qualities of the objects and entities in the television picture. When the image is viewed, it is only necessary to present the visual qualities, that is, color, hue, and intensity of the points of light that were captured. What those points of light are qualities of is irrelevant, so long as they are presented in the same configuration that exists in the scene being captured. Those points of light that represent the visual qualities of each object will be those objects in the TV picture, without any processing or integration, because those objects, visually, are whatever those qualities captured and displayed are.
Perception works in exactly the same way. If the field of perception includes objects, animals, and people, it includes them. It does not include them as objects, animals or people. It simply includes all the perceptual qualities just as they are. Since the objects, animals, and people are whatever their qualities are, and those qualities are what the sense organs sense, those qualities which are an object, when perceived, is perceiving the object, and those qualities which are an animal, when perceived, is perceiving the animal, and those qualities which are a person, when perceived, is perceiving a person. Since all of these, as well as the background are only whatever their qualities are, when those qualities are perceived, it is the existents themselves that are being perceived. There is nothing else to perceive.
Perceiving Things As They Are
Almost every theory of perception assumes there must me some process or mechanism for turning the information provided by the sensory nervous system into conscious percepts. These supposed processes or integrating mechanisms are never described, they are just assumed, and they are all fictions.
Perceived qualities do not need to be integrated into entities, they already are "integrated" in the entities themselves. What is perceived is that "integration" as a configuration of qualities, just as they are organized in the entity itself. It is not necessary to mentally "create" entities from perceived qualities because the qualities of those entities are already organized as those entities. To perceive those qualities in that organization is to perceive the entities.
The supposition that whatever is "detected" by the sense organs and provided to conscious must in some way be organized and integrated before entities can be perceived presumes the sense organs and neurological system in some way disorganize, confuse, or rearrange the qualities of things detected, and must then reorganize them in the way they were already organized in the entities to begin with.
The conclusion is that all the qualities of existents are already configured or "integrated" into the existents they are. To perceive an entity it is only necessary to perceive those qualities in the very configuration in which they are already organized as qualities of the entity. The qualities do not need to be configured or integrated all over again by the brain or any other organ in order to perceive those existents exactly as they exist.
How We Perceive A Red Rubber Ball
Imagine a red rubber ball sitting on a white table. Physics and physiology tells us, when we look at the table, the lens of the eye causes a miniature image of the scene to be projected onto the retina where light detecting rods and cones are stimulated to send sensory data to the brain. If we reach out and touch the ball, and squeeze it, the nerve endings in our finger tips and those sensing pressure and muscle tension are stimulated to send more sensory data to the brain. Though physiologists, particularly neurologists, have been able to detect and map responses of the brain to this sensory data, science has not yet been able to determine exactly what those responses are doing. In some way, of course, we know they are related to our conscious perception, but perception is not brain activity. Ultimately, from the perspective of philosophy, the exact relationship between that brain activity and our perception does not matter. What does matter is what the resulting perception is.
While we do not, and may not ever know, exactly how the brain's behavior is "what is presented to consciousness," that is perceived, it apparently is, or is at least related to it, because perception can be altered if that brain behavior is altered. What we know is the perception itself. What is not presented to consciousness is percepts of entities, such as a "percept of a red rubber ball." What is presented to consciousness are perceptual qualities in the form of patches of color of various shades, feelings of pressure and a sense of muscle action. There is in this case a round patch of red color someplace on a field of white and grey which is on a field of other colors and shading. There is also a pinkish blob of color that faintly resembles an octopus partly obscuring the round patch of red. When the tentacles of the pink blob move, the shape of the patch of red color changes slightly, and that is accompanied by a feeling of pressure on the fingers and a sense of muscle action. The patch or red and pink blob of course are the red ball and our hand and fingers.
It is possible to actually photograph the image that is projected onto the retina of the eye. If we should do that while looking at our red rubber ball, we would discover it looks exactly like the scene we are looking at (except upside down). If it were possible to photograph our perceptual field of vision while looking at our red rubber ball, we would discover the two photographs (that of the retina and that of our perceptual field of vision) were identical. Both would have a red rubber ball in them presented in the same way. Notice, absolutely no processing was necessary to create an "image" of the entity (red rubber ball) in the image on the retina. All that was required was for the colors, light, and darkness of the scene to be faithfully transmitted to the retina of the eye. Though it is not yet understood how, and except for the fact that it includes the perceptions of sound, touch, taste, smell, and internal "senses," as well as the visual, that is all the neurological system must do: faithfully transmit and present to consciousness all the attributes (color, temperature, sound) of whatever is made available to the senses.
No special processing of any kind is required for entities or things to be perceived or distinguished from their background. Things are perceived in exactly the same manner their background is perceived, which is actually other things. Real things are what they are because of the attributes or qualities they have and are distinguished from other things by those qualities. Not all the qualities of anything are available to the senses, and thus our consciousness; only those that are we call the perceptual qualities of things.
In the case of the red rubber ball, the perceptual qualities are its color (visual) and the way it feels (tactile). The roundness of the ball is not a perceptual quality. There is no sensory data for "roundness" transmitted to the brain, because there is no visual means for capturing, "shape," only color and intensity. Technically, and this is very important, shape is not a perceptual quality.
This seems, for many a very difficult concept, but once it's grasped, almost all the other problems about perception dissipate. In the visual field, all that is directly perceived are colors and intensity. Everything else we think of as perceived are merely configurations of shades of colors, and by means of these, everything else we perceive is there. For example no shapes are presented to our visual consciousness, only patches of color; but those patches of color may have any shape. It is not necessary (or possible) for the neurological system to capture or transmit any information about shape to the brain for the shape of every patch of color in the visual field to be precisely represented.
Just as it is not necessary for any information about shape to be part of perceptual qualities for us to perceive shapes, there is no need for any information about entities (except their perceivable qualities) to be provided to consciousness for us to perceive entities or things. All that is necessary is for all the perceivable attributes available to the senses to be presented to consciousness exactly as they are in the entities or objects being perceived.
Whether the perceptual field is an animal's, a young child's, or an adult's, when looking at the same scene, the visual fields will be identical. The animal will see objects, and may "recognize" some that it has encountered before or it's instinct provides recognition of as things to fear or things to eat. It will not be able to "identify conceptually" any of them. The child will see all the same objects, but, depending on age, may be able to identify some, such as Mommy and Daddy or his own toys, but things the child has not seen before, though seen in exactly the same way the adult sees them, he will not be able to identify conceptually. The adult will probably be able to conceptually identify everything in his visual field, but their will be nothing in that field that is not identical to what is in the animal's and the child's visual field.
[Note: This is a generalization, of course. Poor eyesight, some animal's inability to see color, etc. will cause differences in the visual field. Those differences are because all perception is contextual, and perceptual equipment is part of that context.]
Perception Contextually Perfect
There is a common argument meant to cast doubt on the validity of perception called perceptual illusion. A frequent example is the so-called "bent stick" illusion. The argument is based on the fact that a straight stick immersed half-way in water looks bent, implying that vision is an unreliable means of perception, because it can be fooled into seeing a straight stick as a bent one. The illustration actually demonstrates the validity of perception, however, not its vulnerability.
If our perception of the real world is to be reliable, it is the physical world as it actually exists we must be conscious of, and that is exactly what our perception of the world is. In the real metaphysical world nothing exists independently. The third ontological corollary of identity is: Anything that exists must have some relationship to everything else that exists. Those relationships, together with its state, constitute an existent's metaphysical context.
Almost every argument against the reliability of perception ignores or evades the fact that perception, to be reliable, must represent existents as they actually are, which includes their total present metaphysical context. A straight stick lying on the ground, and a straight stick immersed in water are not the same metaphysically. If perception perceived these two different metaphysical existents in the same way, that would be illusory.
What is held up as evidence of the unreliability of perception just happens to be evidence that perception is not only much richer than any of these critics supposed, but perfect and totally reliable, because perception is always contextual—every percept is an exactly correct representation of what is being perceived in its total metaphysical context. If this were not true, perception could not be the source of knowledge about existence that it is.
The metaphysical context of what is being perceived includes every relationship to that which is being perceived, as well as the state of that which is being perceived. If a white piece of paper is being perceived in the context of a red light, the paper appears to be red, which is exactly how it ought to appear in that context. If someone is wearing blue tinted glasses, everything being perceived will be tinted blue, which is exactly how it ought be perceived in that context. If white paper appeared white when illuminated with red light or if things were not tinted blue when one is wearing blue tinted glasses, perception would be deceptive, and that deception would inhibit, if it did not totally prevent, us from learning about the nature of light, for example.
Part of the total metaphysical context of anything that is being perceived is the perceiver. The fact that things appear differently to us depending on perspective has been offered is evidence that perception is unreliable. It is, in fact, more evidence that it is totally reliable. When we view the same thing from different positions, or under different conditions, the metaphysical context is different. If things appeared the same when we are close to them as they do when we are farther away, that would be a perceptual mistake. The wonder of perception is, that it always gets it right and automatically accounts for every metaphysical variation including those variations of which the perceiver is a part.
The fact that our internal states affect our perception of things is presented as more evidence that perception is unreliable. If there is a change to the state of some aspect of the neurological system, our perception will be affected by it. If the circulation in our arm is cut of temporarily, we have the "sensation" of "pins and needles" which itself is the perception of a metaphysical state, but that state will also make the things we feel with our "numb" fingers different than the way they will feel when circulation is restored. To expect something to feel the same in the context of being felt with numb fingers, as well as with fingers that are normally sensitive, ignores the fact that our perception of things is always in their total context.
Perception is never "mistaken." What is perceived is what is perceived—perception makes no judgments. All the mistakes that are made relative to perception are made conceptually and are about what is perceived, and never caused by perception itself. Whenever there is anything questionable about what we perceive, if something seems, "not right," it is not an indication that something is wrong with perception, it is an indication there is some metaphysical fact related to our current perception we are either unaware of or do not understand.
[Note: The idea that percepts "cause" ideas or concepts, that somehow our consciousness automatically programs our conceptualization is another error subtly introduced to philosophy by the "false empiricists" (all those labeled that with the exception of Locke), especially Hume.]
One other argument made against the validity of perception is that learning and experience change the way we perceive things. The word learning is used in a general way to account for all forms of changes resulting from experience, including non-cognitive habituation, development of physical skills and the content of memory, to cognitive conceptual learning. All of these things will affect how one responds to what they perceive, but none of them affect the nature of perception itself. A child that has not learned the alphabet sees a page of letters in exactly the same way an adult does. The letters are just meaningless marks to the child. Learning the alphabet does not change what those letters look like—if it did, the alphabet could never be learned. [Does it not occur to those psychologists who claim that learning changes our perception, since all we learn is based on what we perceive, if what we learn changes what we perceive, it would invalidate what we learned?]
There is some indication that learning has some small effects on some brain structure. Whether that really has any affect on the perceptual field is questionable. If it does, it would be slight, and would, in fact, be another example of perception accounting for a metaphysical fact which is part of the total context of what is being perceived.
World as Perceived the Real World
What we directly perceive is the real world, and that world is exactly as we perceive it. The world as we perceive it is the, ultimate reality.
What I mean by the, "ultimate reality" is that aspect of reality that is primary, the fundamental existence without which there is no other existence. Most philosophers who consider this question assume it is either an ontological question (what is the ultimate stuff or nature of existence?), a cosmological question (where did everything come from or how did it come to be), or a scientific question (the supposed answer being some GUT—grand unified theory of everything).
The question is neither ontological, cosmological, or scientific, because the ultimate reality is what ontology, cosmology (which is neither science nor philosophy), and the sciences study. The ultimate reality is material existence, the physical characteristics of which we are directly conscious of, it is the world we perceive as we perceive it. Physical existence is all that consciousness can be directly conscious of, and it is that physical existence which is the ultimate reality or primary existence. Though our consciousness, and the life that makes it possible are not themselves physical attributes, without the physical there would be no life or consciousness.
Most people today doubt that the world they directly perceive and live in is the ultimate reality. They have been taught there is something more, "fundamental," like the fundamental particle's of physics, or some ultimate "force," which is the ultimate reality responsible for the world we perceive. Most people doubt the reliability of perception (which they mistakenly refer to as the senses), as well. They are certain perception is subject to distortions, illusions, and deceptions. Almost no one really believes reality is the world we directly perceive or that it is exactly as we perceive it.
Except for some pre-Socratic philosophers, the view that the perceived world is the real world has never been held explicitly and unambiguously by any philosopher since the sophists began to question it and Plato utterly repudiated it, obliterating it from all future philosophical consideration. There is probably not a serious philosopher today who does not consider this view na´ve.
In fact, it is na´ve. It is the view implicitly held by all unsophisticated people, when they are not thinking in terms of their religion. The reality they see and directly experience is reality, for most people, and if philosophers, scientists, and theologians did not come along and give them reasons to doubt it, there would be no reason at all to question that na´ve view.
Reality is the cold hard earth, and soft green grass, the trees, rocks, rivers, oceans, and mountains we see, feel, hear, smell and taste. It is the onions, peppers, and fish we smell frying; it is the heat of the stove we feel; the shiny silverware on the table we see and the clinking of the table being set; it is the softness and texture of skin and clothing we feel. These are reality and the way these things look, and feel, the sounds they make, how they smell and taste are what they really are.
It is that reality all intellectual inquiry is about. It is what the sciences study and philosophy attempts to explain. When science tells us those things are not real, that some discovered fundamental particles or forces are real and the world we experience is only an illusion caused by them, the scientist is admitting what he studies is unreal, and all his conclusions are based on an illusion. When the philosopher tells us the physical world is not real, but only an illusion caused by the function of our brains, the philosopher is admitting that he and his brain are not real and that all his conclusions are caused by that which does not really exist.
In our na´vetÚ, we know this world we perceive and directly experience, live in and die in and are part of, is the real world. What sort of "sophistication" ever makes us doubt it? Any science or philosophy that questions the reality of this world we perceive and live in is not sophistication at all, it is only sophistry or superstition.