This diagram is a map of the human condition that emphasizes the levels of reality and of mental processing. The general idea is that adjacent blocks connect in an intimate way and that non-adjacent blocks must communicate through intervening layers unless there is a connector arrow. The large-scale division is into the Physical World, the Body and four layers of Mind. Except for the topmost Storytelling layer this map also describes all mammals (though the functioning of the mental layers 2 and 3 is considerably richer in humans.)
Do not read too much into the specific dividing lines given here, supposing that the implied communication directly corresponds to neural pathways. The brain has complex and diffuse connectivity which (insofar as it is even known) does not lend it self to simple graphical representation. For example, Eye–hand coordination integrates perception, Body Model, Action and intention.
The primary goal of this map is to show an organization of mind from the viewpoint of consciousness, and to emphasize the magnitude of unconscious processing. The vertical axis represents a transition from the real and deterministic physical world to the arbitrary and unpredictable mental world, with each layer becoming less real and more unpredictable in its behavior. This appearance of arbitrary and unpredictable behavior with increasing complexity is the process of Emergence. There are also two gradients that (not coincidentally) happen to vary across the mental layers. We are completely unconscious of the workings of the first mental layer, and our conscious awareness gradually increases as the layers go up. Similarly, the data rate decreases from megabits per second at the raw sense data and muscle command interface down to bits per second at the level of conscious symbolic processing. Only one bit in a million makes it into our conscious awareness. See Unconscious.
The physical world is the common substrate of everyone's existence, and is the gold standard of what is real. The Reality of any higher levels is a matter of taste and convenience. The physical world is also pretty deterministic at the human scale—we usually know what mindless objects are going to do next (but see Physical Chaos).
The body is part of (submerged in) the physical world, but it does have a well-defined boundary that is defended mechanically, biologically and mentally. We normally think of ourselves and other animals as agents that sense the surrounding environment, form intentions, then act, modifying the environment to achieve their goals (see Intentional Design.) Humans are fundamentally social, so other humans are one of the most important parts of the surrounding environment.
Though physics may ultimately tell us some limit, the physical world presents us with what is effectively an infinite amount of information, of which our senses encode a vanishingly small part into nerve impulses for mental processing. For example, human vision senses approximately 10 megabits per second, but the physical limit for a human-sized eye is about 1×1018 times greater (more on sensory limitations.)
We use our muscles to modify the environment, and our proprioceptive sense gives us feedback on how we are moving.
Via the Autonomic nervous system our brain is constantly sensing and controlling the state of our body's life-support systems. This activity is almost entirely unconscious, but is closely integrated with our emotions.
In humans the brain is a relatively large and costly organ, so it must be doing something pretty important in keeping us alive and helping us to reproduce. The brain is the physical substrate of the mind, which we show as levels stacked on top.
We consider mind in a broad sense, meaning any processing of signals or representations done by the nervous system. Once we distinguish mental phenomena from the physical we create some sort of Mind/Body Dualism. Although all mental processing is a direct consequence of the physical structure of the brain, there is undeniable value in considering mind to be distinct from its physical implementation and in saying that mental events can cause other mental events. We can do this because by design the brain insulates mental events from unwanted physical influences (see Mind.)
In the level map we have picked out a handful of mental capabilities and organized them into four levels of increasing conscious awareness (and decreasing bit-rate.) The division into discrete capabilities and levels is of course rather arbitrary; the point is the general trend that our more controllable, more conscious mental capabilities necessarily operate on highly processed and reduced digests of perception.
The first layer (Action, Body Model, Memory and perception) are capabilities which to us are largely a black box. We can form an intention to initiate Action, but we ordinarily have very little understanding of how we use our muscles to move or to accomplish tasks. The functioning of our Body Model is usually so intuitive and accurate that we easily fall into the trap of Naive Realism, supposing that we somehow directly know that we have limbs, and how they are positioned. But in disorders such as phantom limb syndrome, we see that the sense of having a limb, feeling it move, and feeling it in pain, these all are only perceptions mediated by the Body Model, which can exist in the absence of any actual limb.
Although memory and perception may be in some ways more elaborated in humans that other animals, the general structure of the first layer in mind is largely inherited from those ancestors.
With both Memory and perception it is important to understand that while we can try to remember something, or direct our attention to something, memory and perception function all the time, and it is well established in by numerous threads of cognitive and behavioral research that perceptions or memories that we are not consciously aware of can still strongly influence our behavior. Early applications of an information processing view of mind in cognitive psychology regarded the unconscious information reduction from perception into consciousness as a filter, where that which did not become conscious was simply lost, but it is now clear that unconscious perceptions and memories can influence our behavior, largely by their effects on the second layer.
The second layer of mind (Emotion, judgment, belief) is in many ways the unconscious substrate of consciousness. We could never accomplish anything useful by conscious thought if we did not have our emotions to tell us what is important, our judgment to reduce diffuse experience into definite opinions and to tell us when we have gone far enough in conscious consideration and it is time to decide, and we also rely greatly on our subjective assessments of what is true and of how reliable our knowledge is.
The functioning of this level can be described as intuitive, in that we can be aware of how we feel, we can know what it is that we think should be done, we can know what it is that we think is true, but our attempts to explain these things are a Story. We do not know all of the countless subtle factors that are weighed by our intuitions. If we are a good storyteller, then we will carefully test our stories against our intuitions, refining them, so that they best express our wisdom and experience, but this construction of meaning from experience is a creative process, not a simple matter of introspection. The theory of Representational Opacity goes some way toward explaining why this so.
intention and attention are generally regarded as conscious processes in humans, but non-human animals also act as though they have intentions (see Intentional Design) and clearly have limited attention which must be directed somehow. While animal experience is surely much different than human experience, it isn't a meaningless anthropomorphism to say: “The raccoon was trying to open the garbage can, and didn't notice when I came outside.” We can consciously direct our attention, but there is clearly a significant bottom-up factor in attention, where a perception “seizes our attention”, and this mechanism surely derives from our unconscious forebears. The situation with intention is particularly confusing, because non-conscious animals, computer programs, and even plants, can act in an intentional way, yet we see our intention as being the result of consciousness, and may feel that any agent that isn't conscious can't have true intention. This transitions to the next layer, by way of the The Interpreter Theory.
The highest layer of mind is that part which seems most clearly conscious, that of narrative: what we are saying out loud, or thinking in some internal dialog. The Interpreter Theory of consciousness accepts that yes, this is indeed conscious, but that also this is largely a Story that we create to explain workings of the mind we don't truly understand (because we have no direct introspection into the intuitive processes the mind depends on.)
It is only in the layer of storytelling that we reach a uniquely human capability, and this is above all a social capability (see The Argumentative Theory.) Humans have the capability to explain why they did something or to argue why something should be done because they function in a social context where this is necessary. Non-human animals do need to form intentions to direct their effective action, but have no need to explain these intentions. The human need to explain and persuade has has been addressed by evolution through the addition of a new capability, the storyteller (or interpreter.) The storyteller observes what we are doing and comes up with a story about why we are doing it.
This story is not entirely a fabrication because the storyteller does have some privileged access to our mind (mediated by layer 3), but the intuitive and representationally opaque nature of layer 3 means that the storyteller doesn't have all the information, and in fact, by a principle of “need to know”, cognitive biases such as confirmation bias insure that the information made available is precisely the information that is useful to construct a convincing story. Unhelpful details such as contradictory evidence or conflicts due to self-interest are unconsciously excluded from our awareness.
This model corresponds in some ways to Dennett's physical, design and intentional stances. Of course, the physical world can in general only be understood from the physical stance. The body is part of the physical world, so the physical stance applies, but as the product of evolution we can also apply the design stance. The mind has also evolved, so all mental layers can also be examined from the design stance. The intentional stance only applies above the unconscious bottom layer.