Epistemology is the study of how we know and how and why we generate knowledge. I am going to summarize here part of what I know about it. Most of this I learned from my mentor in philosophy, Dr. Ramakrishna Puligandla, Ph.D., who is not only a philosopher, but also a top notch theoretical physicist.
So, let us ask first, why do we pursue and generate knowledge?
You have no doubt noticed that when you question someone's knowledge, the individual will often react quite defensively or aggressively. Often, people go to war to defend systems of knowledge (i.e. what they believe is true). This tells us that some primal emotions drive the pursuit of knowledge.
People look at the vast and unpredictable universe around them, feel fear of the unknown, and particularly, of death. To reduce this fear, they seek knowledge, through which they hope to control the unknown and stave off death. Hence, fear or dis-ease motivates all striving for knowledge. Knowledge is sought as a balm for dis-ease.
People believe that if they know (are "right") they are protected from the unknown, and if they don't know (are "wrong"), they lack protection, are vulnerable. Hence, knowing/not knowing is a life-or-death situation.
Consequently, when you question someone's knowledge, you question their security. This is why questioning is not well tolerated by many individuals, and they may react violently to any questioning of their "knowledge." If you question someone's knowledge, you are (often) questioning their very security of being.
Everyone agrees that reality exists. However, descriptions of reality vary from person to person, culture to culture. Why?
Knowledge consists of systems of percepts ("data") and concepts (names, categories, and explanations). Disputes can be factual (about data) or theoretical (about explanations). Solving disputes about data involves simply producing the data or evidence. Disputes about explanation are a whole other ball game.
We can only know what our perceptual and conceptual apparatus allows us to know. Thus, humans can only see what our eyes allow us to see, hear what our ears allow us to hear, taste what our tongues can taste, and so on.
Without doubt, if we had different perceptual apparatus we would describe the world quite differently from the way we presently describe it. For example, if, like most carnivores, we did not have color vision, we would not have colors in our description of the world.
For another example, other species appear to hear noises, or see things, which we do not see. Certainly the cat perceives things (e.g. sounds, odors) we do not, and we perceive things (e.g. colors) that cats do not.
This means that while we have only one reality, we have multiple perceptual worlds: human world, cat world, bird world, etc. These worlds all overlap, but they differ due to the different constitutions of each species.
Moreover, if we alter our own physiology, for example, using psychotropic drugs, we will perceive things not perceptible when in 'normal' physiology.
All this indicates that knowledge is inextricably bound up with our psychophysiological constitution, and that what we perceive is as much a function of our equipment as of reality.
Some may believe that what we perceive in the 'normal' physiological state is 'real' and anything perceived in an 'abnormal' or 'nonordinary' physiological state is 'unreal.' This view suffers from a glaring problem, namely that nothing we perceive comes stamped with any mark identifying it as 'real' or 'unreal.'
Some people (let's say, most psychiatrists) will put visions obtained under the influence of mescalin into the category 'unreal,' while others (let's say, shamans) will put them in the category 'real.' This is sufficient to demonstrate that 'real' and 'unreal' are concepts, not percepts.
I would argue that we have no reason to put any experience in the category 'unreal.' If you experience it, it is a part of reality. This is true whether you experience it in a 'normal' physiological state, or an 'abnormal' physiological state. We have no evidence showing that what is 'normal' is more real than what is 'abnormal.' Whether any individual can discern meaning in any particular 'abnormal' percept depends on her conceptual framework.
We have no a priori reason to believe that any particular perceptual apparatus (say, human) is more accurately tuned to reality than any other (say, cat), or that only one particular state of the human apparatus (rested, tired, fed, unfed, awake, dreaming, without drugs, with drugs) provides the only correct information about reality, but we can say that particular states may not provide correct information about the world.
Let me explain. Reality consists of all existence; it includes all possible experiences, such as, for example, waking experience and dreaming experience, cat-experience and human-experience. We know that these experiences differ, but they overlap. If any experience occurs, it perforce belongs to reality. So, for example, if you trip out on mescalin, this experience will give you accurate information about reality, namely, about what happens to a person's experience when he takes mescalin in a large enough dose.
Our world consists of all the experiences we have as individuals. Because of inevitable individual variations in perceptual apparatus, each individual lives in a slightly different world than others. We know this to be true because, for example, color-blind individuals live in a color-free world, as do cats, while those of us who can see colors live in a colored world, as do other primates. The worlds of individuals of the same species overlap almost completely, but as perceptual apparatus varies among species, we have good reason to believe that the worlds of different species are quite different. For example, we have evidence that the worlds of some species may not include what we call pain, or at least, that their experience of stimuli that cause us pain is significantly different (simply, they don't have the types of nervous systems that appear necessary to have the experience of pain as wee know it).
We can measure the value of states of consciousness by their survival value in our shared world, although only on the assumption that survival, or avoidance of premature death, is 'better' than non-survival. Thus, if someone drives off a cliff while driving under the influence of alcohol, because the alcohol altered their perceptions, we may say that the alcohol-induced state provided the person with incorrect information about the world, but not about reality. It gave them accurate information about reality, i.e. that taking alcohol will provide perceptual variations of a certain type, but due to this influence of alcohol on their perceptual functions, alcohol gave them innaccurate information about the world.
We all naturally value survival over non-survival, but do we really know that survival is 'better' than non-survival? One of the most unnerving aspects of our world is death. It appears that nature has decided that death, or non-survival, is a requirement of life. Under these circumstances, we can only judge survival as 'good' from our human perspective; Nature appears to consider death as 'good' as life, or more accurately, death of many beings (foods) is essential for the survival of one being (you). Therefore, your survival is 'good' for you, but 'bad' for those that you eat.
Our knowledge is inevitably conditioned by the limits of our perceptual apparatus.
The human mind perceives things not perceptible by the five senses, such as relationships, patterns, mathematical entities, and meaning in general. Your eyes perceive these marks known as letters, and your mind perceives the meaning of these marks.
The human mind also generates concepts to organize its percepts into systems of knowledge. All systems of knowledge are therefore conceptual frameworks. Thus, we can talk about the Aristotelian conceptual framework, the Newtonian, the Darwinian, the shamanistic, the Christian, the Hindu, etc., etc.
To restate, conceptual frameworks are systems of concepts used to organize and explain the occurrence and behavior of phenomena detected by our limited perceptual apparatus.
Concepts of certain aspects of the world can and do vary from framework to framework. For example, according to the Newtonian conceptual framework, space and time exist independently of each other and the observer, but according to the Einsteinian framework, space and time exist as a spacetime continuum, and relatively to the observer.
We have two basic types of concepts: empirical and theoretical. Empirical concepts refer to entities that we experience through the five senses, such as colors, textures, velocity, mass, direction, and so on.
These entities are not self-explanatory; if they were, we would not do science to create explanations.
In its attempt to explain phenomena (perceptual data), the mind generates a class of entities called theoretical entities.
Gravity is an example of a theoretical entity invented by Isaac Newton to explain the universally observed fact that objects will drop to the earth if released into free fall from a position above the earth.
It is of utmost importance to realize that Newton did not discover gravity while rummaging around the countryside looking for a 'force' to explain why things fall to the earth. You can't open the earth and find gravity there. You can't put a piece of gravity on your table. Gravity is an idea, not a physical entity. Newton did not discover gravity, he invented it.
To drive this home: Gravitational force has no shape, color, flavor, sound, or texture, no perceptual characteristics. You just won't find it anywhere among the physical furniture of the world.
Some will protest: "Well, if you think gravity only exists in the mind, why don't you jump out of a 20 story window?" These people mistakenly think that the fact that things fall toward the earth proves that gravity exists the same way that trees and computers exist. Not so.
I don't jump out 20 story windows because I will fall to the ground and probably kill myself if I do so. It makes absolutely no difference to me what causes this fall. I don't have to believe in any invisible gremlins or gravity to know that if I fall 20 stories to some pavement, I will die.
This would occur regardless of whether this fall is a result of the action of a theoretical force called gravity, or a result of my body being composed primarily of the earth element which naturally moves toward the earth, as opposed to the fire element and air element which naturally rise away from the earth.
You see, before Newton invented the idea of gravity, people didn't know that gravity caused things to fall to the earth, but they didn't jump out windows either. Previous to Newton, in the Western world, scientists explained things using Aristotle's physics. According to Aristotle, if a thing falls toward the earth, this indicates that it is composed primarily of the earth element. In other words, Aristotle had a different explanation for what happens. He proposed a theoretical entity called earth element to explain why some things fall toward the earth and also the fire and air elements to explain why some things rise away from the earth.
Recall also that people did engineer buildings and bridges, not only in the West, but also in ancient China, without having any grasp of Newtonian physics, i.e. without any idea that objects fall to the earth because gravity acts upon them.
Someone will protest, "But we can measure gravity." Really?
In physics, no one measures forces like gravity directly. We don't have gravitometers. To "measure" gravitational force, we go indirectly, by measuring mass and acceleration of physical bodies, from which we calculate the force using the following equation:
Force = mass x acceleration
We measure mass in grams and acceleration in meters per second per second. We can only know the magnitude of the force by measuring the mass and the rate of acceleration, then performing this calculation.
But then when you consult Einstein, gravitation is not a force anyway, it is a function of spacetime curvature.
So if gravity is like rocks, a purely physical phenomenon, how is it that Newton can say it is a force, and Einstein can say it is a curvature of space-time? Think about it. Did Einstein dispute Newton by producing a bit of gravity, and saying "Come on, just take a look, its obvious that gravity is a curvature of spacetime. How could you have ever believed that it was a force?"
The perceptive reader will realize that everything I say here about gravity applies to all forces invoked in modern science.
For an example relevant to the field of biology, including nutrition, it also applies to the concept of energy. Like gravity, energy has no shape, color, sound, odor, or texture. If you think otherwise, I invite you to show me a bit of energy.
As with gravity, we "measure" energy by calculating work. In physics, we define work as the product of force and distance. So what do we actually measure? Mass, distance, and movement speed of objects. From this we calculate the energy involved.
In chemistry and nutrition, we "measure" energy in units called calories. We define a calorie as the amount of heat required to raise the temperature of one gram of water one degree centigrade. Again, we never measure calories directly. We measure the movement of matter (e.g. the movement of mercury in a thermometer).
By the way, have you ever seen a calorie?
Theoretical Entities Presupposed in Ordinary Science
Modern scientists use the ideas of gravity and energy as central parts of their conceptual framework. Most scientists actually assume that gravity and energy are phenomena (part of the furniture of the external world). If you think scientists are actively engaged in trying to falsify the idea that gravity causes things to fall to the earth, or that energy exists, you don't understand how science works.
Few scientists question the very foundational concepts of the science in which they operate. Most accept the foundational ideas like gravity and energy and use them to conduct 'normal' science. Only now and then do we see some unusual individual (Newton, Einstein, Darwin, etc.) who questions the foundational concepts of any particular scientific enterprise (physics, chemistry, biology, etc.) and revises old concepts or creates new concepts to organize and explain the data in a new fashion.
In fact, in order to pursue conventional Western science one has to accept gravity as a given. If you start to question whether gravity exists or causes the convergence of matter, you are no longer practicing Western science, you are undertaking a revision of Western science. And to take this position, you would have to be looking at Western science as just one of many possible ways of understanding how things work, not accepting it as 'the way things REALLY work.'
Most people can't tolerate free-fall of conceptual understanding, so they won't question a basic assumption like gravity unless they already have an alternative foundation on which to stand. Since most people accept gravity as the only reasonable explanation for why things fall, they will never question it.
Probably you never heard of the Aristotelian explanation until you read this blog, and almost certainly you never heard that the Aristotelian explanation was well supported by data at the time it was accepted.
Realize that when you were taught about gravity or energy, no one offered you a variety of alternative explanations for why things fall or move around, leaving you to decide which of those made the most sense. You were involuntarily indoctrinated to make you a member of the gravity and energy cult. No one even pointed out to you what I have just pointed out in this article. This applies whether you are a layman or a trained scientist.
Alternative Theoretical Entities
Unfortunately, many people, including many scientists are not aware of the fact that modern science is full of theoretical entities, like gravity, quarks, positive charges, negative charges, electromagnetic waves, energy, and so on. These people assume that quarks exist the same way that rocks exist, and will summarily dismiss as absurd any theoretical entity proposed by alternative conceptual frameworks.
As an example, shamans the world over use the concept of nature spirits to explain certain phenomena. People unaware of the difference between perceptual entities and theoretical entities will often dismiss the idea of spirits on the basis that "Western science has searched far and wide and never discovered any nature spirits."
The problem here is that nature spirits are theoretical entities. You don't confirm or disconfirm their existence by rummaging around the forest, just as you can't confirm or disconfirm the existence of gravity by looking for it in the English countryside.
Suppose I said: "Well, at long last I have proven that gravity doesn't exist since I have searched far and wide, near and deep, and I haven't seen any gravity anywhere." [Substitute energy for gravity with the same result.] Do you think the physicist would accept my refutation? Or course not. Yet he turns and believes that he can refute theoretical entities proposed in other knowledge systems by the same device.
You don't discover theoretical entities, you invent the concepts as part of an attempt to explain the perceived activities of phenomena. You don't confirm the existence of theoretical entities by direct perception, you confirm their existence by observing and interpreting the activities of phenomena generated by experiments conducted in the context of the conceptual framework to which the theoretical entities belong.
That last sentence means: The concept of gravity is meaningless outside the context of the conceptual framework (Western science) to which it belongs; and the concept of nature spirits is meaningless outside the context of the conceptual framework (shamanism) to which it belongs.
In the shamanistic conceptual framework, the concept of nature spirits serves as a key concept in explanations for certain types of phenomena, some of which are generated and perceived in 'normal' physiological states, and some of which are generated and perceived in experiments entailing 'altered' physiological states.
This analysis applies equally to many concepts found in non-Western sciences.
For example, a key theoretical entity in traditional Chinese sciences is qi (Wade-Giles: ch'i). Western medical people like to think that they can dismiss the concept by stating that Western science has never found any entity like qi in the human body.
I would make the same error if I stated that I have proved that energy does not exist because no one have found any energy coursing through the body or in lurking in the depths of food.
These people have made the mistake of thinking that qi is a phenomenon like blood or muscle tissue, or rocks for that matter. Like energy, qi is a theoretical natural entity which traditional Chinese scientists used to explain a wide variety of phenomena, ranging from physiological to celestial, including the vast difference between a living and dead animal.
In Chinese medicine, qi is defined at that agent responsible for the phenomena of heat, movement, transformations, maintaining structural integrity, and providing protection from exterior influences.
One can readily see that this concept resembles the Western scientific concept of energy in some respects. Namely, heat is thermal energy and movement is kinetic energy. At some later point I will discuss how it differs from the concept of energy.
For now, I will close by recapping:
1. People seek knowledge for emotional comfort, i.e. to relieve the dis-ease that arises from feeling small and powerless in a vast, unpredictable universe.
2. Knowledge systems consist of percepts (sensory data) and concepts, along with rules about how to arrange concepts into explanations (i.e. logic), and procedures of experimentation the produce data that begs explanation.
3. All knowledge systems are limited by our perceptual apparatus.
4. Knowledge disputes can be about data, or about explanation.
5. Explanatory concepts connect to empirical concepts, but they do not consist or even necessarily include empirical content (color, shape, odor, texture, sound, flavor).
6. You can't refute an explanatory theoretical concept by searching in the physical world for the entity proposed by that concept, whether it is gravity, energy, nature spirits, or qi.
7. Theoretical concepts obtain their meaning from their explanatory power or utility in guiding action but only in the context of the conceptual framework (knowledge system) in which they occur.
8. We can measure the value of a conceptual-perceptual framework by its ability to facilitate survival of the human species. If the actions and technologies that arise from application of the framework promote survival of the individual, the species, and the resource base of the species, then we can judge it relatively 'good', and if they reduce the survival of the individual, etc, then we can judge it relatively 'bad,' keeping in mind that this judgment is only true relative to humans, not an absolute truth.