When the Italian mathematician Eugenio Beltrami proved unequivocally that the fifth of Euclid’s five original postulates could not be proved nor disproved from the first four, he settled an age-old debate over the validity of non-Euclidean geometry. By showing that this postulate was an independent idea, Beltrami showed that non-Euclidean geometry was as logically consistent as Euclidean geometry. That is, one could either assume the postulate was true or it was false and still construct a completely consistent system of geometrical ideas. Likewise, the ideas of the mind and body are independent of everything else we know and thus can either be accepted or discarded. No matter which view we take, all phenomena can adequately be described using the assumptions that follow from each particular view. As an example, physicalism, idealism, and dualism each can sufficiently explain the notion of consciousness.

First, we approach consciousness through physicalism, that is, we assume that material (physical) things exist but non-material (mental) things do not. Then the question becomes: Can we, as observers of others and ourselves, describe everything we believe to be consciousness in purely physical terms? The answer, although not obvious, is “yes.” To begin to show why this is the answer, the term consciousness must first be clarified. Since we have started with the basic assumption of physicalism, and we are merely trying to show that physicalism alone is enough to explain consciousness, we can only define our observations of consciousness as purely physical characteristics. That aside, Webster’s definition of conscious is “aware of one’s own existence, sensations, thoughts, surroundings, etc.” Then, using the definition of “aware,” we arrive at consciousness being “the state of having knowledge of one’s own existence, sensations, thoughts, surroundings, etc.” Knowledge, in the purely physical sense, is just the acquaintance with facts, truths, or principles. In turn, obtaining knowledge happens in only two ways: hard-wiring or learning. Learning is knowledge obtained over time and often by trial and error or similar methods. It is a dynamic knowledge that changes with every experience. On the other hand, the common computer is an excellent example of hard-wired knowledge. Everything it “knows” it has been programmed to know and has no control over changing this knowledge. However, since the environment of an object is incessantly changing, hard-wiring alone would never be enough for an object to actually be aware. Therefore, we arrive at some sort of criterion for something to have consciousness: it must have the ability to learn about its thoughts, surroundings, sensations, etc. Now, whereas this gives a definite set of criterion for consciousness, it does not yet explain consciousness in completely physical terms since the ideas of sensation and thought are too obscure. At this point, we can turn to the area of study that deals with neural networks. A neural network is an interconnected assembly of simple processing elements called units whose functionality is loosely based on the animal neuron. The processing ability of the network is stored in the inter-unit connection strengths obtained by a process of adaptation to, or learning from, a set of training patterns.(1)  Often, the method of training involves some sort of randomness that is generated by a regular computer. However, every computer scientist knows that the output from a computer is never truly random and is therefore typically referred to as being “pseudo-random.”  Neural networks can be constructed from organic or inorganic materials and the similarities to animal behavior are striking. Even though the most complicated of neural networks created to date are only  eight hundred-millionths (2) of the complexity of the average human brain,  researchers can detect evidence of thoughts, memories, dreams, and obsessions in addition to the networks abilities to learn information and recognize images.(3)  High-level concepts are represented as a pattern of activity across many units rather than as the contents of a small portion of physical memory. Moreover, these patterns are based on the conditions of learning and are therefore unique to each different network. So, consciousness, in a purely physical reality, can be determined by the complexity and/or efficiency of the object’s neural network. From this method, many levels of consciousness arise and therefore it makes sense to say that a rock has no consciousness, humans have an immense amount of consciousness, and animals (along with neural network-based computers) lie at all the possible levels in between. Further, one can now suppose that there may exist beings in the universe with far more complex neural networks than any human, and that these beings have an unfathomable amount of consciousness. This, then, may not completely answer the question about consciousness, but it does strongly indicate that it will be possible in the future to describe consciousness under the physicalist’s basic assumptions.

However, supposed instead of a physicalistic approach to consciousness, one was to hold the basic assumptions of the idealist. That is, instead of only physical entities existing, only mental entities existed, and this whole thing we call a universe is only some sort of dream made up in the mind of some all-powerful being, hereafter called “God.” Then the question at hand becomes: Can we, as observers of others and ourselves, describe everything we believe to be consciousness in purely idealistic terms? Once again, the answer is “yes”, but this answer, too, is not readily obvious. Once more, we must first clarify the definition of consciousness under this foundation of idealism (i.e. we must again stick strictly to our assumptions of idealism). The ideas of matter and energy, as we perceive them in this fictitious universe, arise out of the mind of God, and anything made of matter and energy can be considered ”pseudo-physical”. In addition, matter, energy, and anything pseudo-physical must follow the strict rules that God has laid down which we call the laws of physics. Consciousness must be either pseudo-physical or non-pseudo-physical. If it is truly pseudo-physical, then it strictly follows the laws of physics and for all purposes we can refer to consciousness in the same way we did in the previous paragraph. On the other hand, if consciousness is non-pseudo-physical, then it does not necessarily follow the laws of physics. Since it does not follow these laws, for all practical purposes it can be considered random. So we arrive at a proper definition for consciousness under the idealist’s assumptions: consciousness is that which is totally unpredictable or random. To test this notion of consciousness, we ask ourselves if it describes those things we experience that we believe to be either conscious or not. First, take something obviously conscious, say, a human. Since humans in this pretence are just other minds, they are not subject to causality and therefore cannot ever be adequately predicted. One way to show this is by assuming they were predictable and you tell then what they are about to do. Suppose you say to your friend, “You’re going to drop your pen in 15.3 seconds.” They could simply grasp onto their pen and prove you wrong. Further, even if you took in account that you were going to tell them and knew the consequences, as long as you honestly tell them your prediction, they can always choose to go against it since nothing causal is forcing them to comply. It is from this type of paradox that we can consider other humans, or rather other minds, to be unpredictable. Second, take something obviously not conscious, say, a rock. No matter how we interact with the rock in the pseudo-physical universe, it will always behave in the predictable manner spelled out by the laws of physics. This leads us to question the consciousness of animals. Since animals come in all levels of unpredictability, we can again conclude that animals fill in all the levels of consciousness between the rock and the human. Therefore, our theory passes the test and we can determine consciousness under the idealist’s basic assumptions.

Lastly, we need to consider the dualist approach, often the opinion held by the average person. Under this theory, both mental and physical things exist as well as conscious entities. Since consciousness can be either physical or non-physical in nature, we are given a sort of freedom in our attempt to grasp what determines a conscious object. On the other hand, we are given too much freedom to arrive at a solid answer. For even though we have both the physical and the non-physical realms to argue in, we cannot do so efficiently unless we know exactly how two objects in the separate realms interact. This corresponds to the various dualist theories. However, no matter what the properties of interaction are, a coherent argument for consciousness can be constructed from a combination of the monistic ideas. As an example, a possible dualist theory is one where the learning process of neural networks is not determined by the laws of physics or any mathematical function, but by influences from the mind. Then we can arrive at a notion of consciousness that is similar to what we came to from the physicalist’s hypotheses. The only difference is that we need to further restrict our definition to say that the level of complexity and/or efficiency of the object’s neural network determines the amount of consciousness an object possesses given that the network was formed by a non-physical (or truly random) learning process. This gives us the same result when dealing with stones, animals, and humans as the physicalist’s definition of consciousness but rules out the possibility of neural network-based computers having consciousness (unless, of course, the creator of the computer possessed the ability to bestow upon it a mind). Subsequently, through similar arguments, consciousness can be explained and defined under any reasonable set of dualist suppositions.

From the above, then, it becomes evident that idealism, physicalism, and dualism can each suitably explain the idea of consciousness. It is at this point that one may agree that it is possible that any of these three theories can explain reality, but that even though choosing any of the three theories is logically consistent, only one of them can be the true theory since a true reality exists. An answer to this relies on the notion of reality. If we say a reality exists, then we must have experienced it in some way. Yet, anything we experience, we do so as part of our consciousness. Which of the three definitions of consciousnesses that I have given should we use? This, in turn, depends on what type of reality we are truly a part of. It is here that we reach a circular argument and one can see that since we are unable to experience anything without the use of our consciousness, we are limited in our capabilities and will never be able to arrive at a concrete answer to the characteristic of reality that concerns the mind-body problem.
 

Notes:

(1) Defined in "Computers and Symbols versus Nets and Neurons" by Kevin Gurney

(2) Statistic based on information at: http://www.catachan.demon.co.uk/Projects/Neural/whatare.html.

(3) For further explanation, see chapter 4 of "Visions" by Michio Kaku.