Some time back I got quite curious about the nature of knowledge — call it my epistemological phase. Having worked in the field of artificial intelligence and biomimitic modeling of the brain, I started exploring both the philosophical and neuropsychological underpinnings of knowledge. The philosophical branch (after all I needed to justify the 'doctorate of philosophy' title bestowed upon me!) is legitimately called epistemology. But the advances in brain science have begun to overshadow the philosophical questions about what is knowledge, how do we get it, how do we use it, etc. I've lumped the whole enterprise under one rubric for convenience. I'm sure someone will complain.
My question at the time involved the recognition of a familiar pattern in the kinds of things that were being called knowledge in the literature. The pattern? A hierarchy. It seemed to me that knowledge could be arrayed in a layered structure with each layer up using the layer below. I played around with the ideas and came up with something I call the noetic hierarchy. Later I learned that others had actually come up with a scheme very much like this. The term noetic comes from the Greek nous, meaning mind or intellect, so I am not using it in a strictly philosophically correct manner (episteme means knowledge). But my reason is that mind and knowledge are really part and parcel the same things. The brain processes knowledge to produce mind. So for me mind (including subconscious processes) is knowledge to the extent that nous and episteme are somewhat interchangeable. I think I like nous better because it implies dynamic process whereas episteme implies a static kind of view - at least to me.
This is a diagram of how I view the noetic hierarchy (NH).
The lowest level is the evolutionarily developed affective system — the emotions, feelings, urges, appetites, along with rewards and pain systems. It is the oldest brain areas (stem and medulla oblongata) along with some later evolved centers for routing signals to and from the early perceptual and motor areas of the forebrain. While there is some synaptic malleability (adjustments) the actual knowledge constitutes the most basic biological aspects of life, how to keep the organism functioning and reproducing. It counts as knowledge because it is what life 'learned' over the course of evolutionary time.
The next layer is what I call perceptual/motor knowledge. Most of this is totally inaccessible from consciousness. You have no idea about how you see lines or hear notes but much of your ability is gained either in embryonic or neonate development. The older areas of the perceptual systems, e.g. olfaction, have some aspects of hard-wired circuitry along with synaptic modifications to tune to actual experience. We now know that a fair amount of perceptual coding is gained from experience rather than being of genetic determination. The same can be said for motor knowledge. This is the knowledge of how to move your body to accomplish desired ends. It is also tied to skill knowledge. Some important components of this level of knowledge is that of hearing and speaking language. The actual language components (words, etc.) are learned in the next layer up, but the fundamental basis for language processing is established in this layer.
At the next layer we find the kinds of knowledge that most of us think about as knowledge. This includes explicit (e.g. episodic) memory, implicit (intuitive) memory, and tacit (long-term, inductive) memory. You'll recall that I explained judgment as an ability to use tacit knowledge to guide decision processes in intelligent problem solving. This is also the layer that is normally discussed in epistemology. It is where learning is put to maximum use to encode concepts and where cleverness (intelligence + creativity) operates on problem solving. So much has been written on this topic that I am not inclined to attempt to explain it much here.
Of greater interest to me is the next layer up which I call understanding. This is the layer responsible for explanation, that is, building models of how the world works and making them accessible to consciousness on demand. Indeed, some researchers suspect that understanding is the seat of consciousness. That is a whole 'nuther story.
Note that I've drawn understanding smaller than explicit, et al, knowledge. That is for a reason. Evolutionarily I suspect understanding is part of that new emergent capacity of the brain I've been calling sapience. Cats get cause and effect. Dogs get cause and effect. Chimpanzees get putting 2 and 2 together to come up with a bigger number (many). Being able to grasp an effect is the result of a cause is actually a pretty primitive accomplishment. Snails do it. In fact, to a very small degree bacteria do it. Cause-effect encoding (memory traces) is a first step toward being able to construct actual models of how the world works. You need a lot more neural machinery than what a snail possesses, but with that machinery you can actually build pretty complex models of causal chains. Remember my blog on the inference methods of abduction? The frontal cortex is dedicated to building models of how things appear to work, the physical world (supported by ancient knowledge of gravity, etc.) and the social world (theory of mind) as well as one's self. These models allow the individual to literally anticipate the future, or at least some future. They are the necessary ingredient in planning. But, as I have indicated previously, the capacity for understanding in the average human being is highly limited in scope. You can get the world immediately within your sensory field, but understanding the world outside that field is, well, beyond most people's grasp. Which leads to the highest level in the hierarchy — wisdom.
You can't have wisdom without significant understanding. And so, wisdom is drawn smaller still. Wisdom is strategic, systemic, moral, guidance to decisions about how to best live in the world and leave the world a better place for the next generation. If you understand how the world works, you can use that knowledge to make decisions that lead to a better, more evolved, world. I drew it smaller because it barely exists in this species! At least that is what I conclude based on what I see happening in the world.
The noetic hierarchy is, in part, a reflection of brain structure (architecture), evolutionary history, and mental life. It is just another way to look at the human condition. I believe that the vast majority of people have some capacity (genetically endowed) for every layer shown. But I think the relative proportioning (not meant to be at all actual proportions) is indicative of the status of Homo sapiens today. I believe that evolution can expand the layers, understanding and wisdom, by increasing the brain's capacity to process these kinds of knowledge. I think it is possible. Whether it happens or not...