There is a Non-Physical Basis of Human Consciousness

My arguments will provide a case for physicalism about human consciousness. That is, that the human mind entirely physical, and has no non-physical aspects. Argument 1: The Argument from Neural Dependence Essentially, we never observe human mental processes without also observing processes taking place in the brain. In fact, it seems that mental processes are dependent upon neural processes. In other words, what happens in the mind depends upon what happens in the brain. We pretty much always observe this to be the case. If you were forming new memories, we would observe your hippocampus being activated. If you were enjoying the smell of a nice flower, your olfactory bulb would be activated. In fact, this is precisely what experiments suggest. When subjects are asked to perform mental tasks, whether it be performing a motor task or doing simple arithmetic, those corresponding parts of the brain are activated. Why is it, if there is some non-physical aspect to consciousness, that seemingly every facet of our conscious experience can be explained by a corresponding brain state, or some process occurring within some specific part of the brain? The dependence of the mind on the brain is much stronger than that, however. When you damage the brain, you observe a corresponding effect to the person's mind. If there really were some non-physical aspect to the human mind, one would expect that there should be no such observation. If you get hit over the head with a hard enough blow, you will become unconscious. The simplest explanation is that the damage to the brain leads to the unconsciousness; a clear example of the mind being dependent upon the brain. There is, of course, an alternative explanation to this: the dualist explanation. The dualist can say that the non-physical mind simply interacts with the brain. In other words, that the non-physical mind is a kind of passenger in the vehicle of the brain. This explanation, however, fails as an economical explanation of the data. For it proposes that there is something to the mind over and above neural processes, and it fails to explain what laws would govern such a non-physical mind. The physicalist on the other hand, only has to explain the physical laws that govern the brain to explain the mind, and proposes nothing over and above the brain. Thus, physicalism with respect to the mind is a much simpler hypothesis than the dualist explanation. Argument 2: Plausible Models of the Biological Basis of Consciousness The neural dependence argument is based upon one central idea, the dependence of the mind on the brain. The dependence becomes even clearer, however, when we actually study the brain. We have detailed models from cognitive science of how the brain works, and we are now close to having plausible models of the origin of consciousness: that consciousness is rooted in the anatomical properties of the mammalian neocortex. I would suggest a paper by Eccles entitled "Evolution of Consciousness" for a more detailed examination of the biological basis of consciousness. Nevertheless, the fact that we have never observed anything that we would call conscious without these anatomical properties is a testament to the fact that there is no non-physical basis for consciousness. Argument 3: Other Minds We have no direct way of knowing that anyone besides ourselves are conscious. However, we infer it all of the time upon the basis of behavior. For example, someone responds "ouch" to a pain, or shakes your hand and and introduces himself. This can clearly be explained upon the basis of physicalism, and in particular, if the mind simply is the brain. In other words, if we define mental states physiologically, we have a basis for why we infer people have other minds upon the basis of their observable behaviors. Other people have brains, and I myself have a brain. We both display similar behaviors, from which I infer the consciousness of others. A materialist explanation of the mind is thus the most economical solution to the "problem of other minds". If one takes Descartes' dualist approach, one is irrevocably tied to solipsism. I have thus presented three arguments for physicalism about the mind. The argument from neural dependence, the fact that we have detailed models of the biological basis of consciousness and have never observed anything that is conscious without that biological basis, and that ultimately, a physicalist explanation provides the best solution to the problem of other minds (i.e. why you should believe anyone besides yourself is conscious). It should be noted that I think the best inference to draw from physicalism is that there is no consciousness after bodily death. In other words, there is no afterlife, and consciousness ceases at death. I believe this makes sense because of the neural dependency argument. If consciousness is ultimately dependent upon the brain, which seems to be the case from (e.g. observed cases of brain damage), it makes sense that once the brain stops functioning completely, consciousness ceases. I ultimately believe this is the best explanation of the data.