In an attempt to see how many ways there are to skin the cat of reality, philosophers have come up with numerous ideas about the true essence of reality. Physicalism, dualism, and idealism are the three most common explanations to this question. Yet, these ideas are not equal and therefore one must be the so-called “best” idea. The best idea should be able to account for our everyday experiences consistently. Physicalism best rationalizes the apparent maintenance of personal identity through time, the illusive two-way interaction of mind and body, the experience of subjectivity, and the appearance of human freedom.

Before we can address the notion of maintaining a personal identity over time, one must first define what it means to have a personal identity. In other words, one must answer the question, “What makes you you?” The obvious (but incorrect) answer under a physicalist point of view would be that you are the unique collection of atoms that composes your body. However, are you not now the same person you were five years ago? Surely, though, you do not contain the exact same individual atoms as you did five years ago. Therefore, identity must be described not only by the type and number of atoms, but also by the organization and position of these atoms relative to each other. Yet, this is still not quite enough to clearly answer the question for some skeptics.  It is obvious that the arrangement of the atoms in one’s body is not the same from year to year, or even from day to day. Therefore, in defining what one personal identity is, there must be room for an error in the exactness of the type, number, and position of the atoms. Further, if one were to write a mathematical formula for this error, it would be a function depending on time. And if we pick any arbitrary time to exactly define who a certain person is and set this time equal to zero, as the absolute value of time increases form that point, so would the error in who that person is according to our definition. This would of course mean that over a long interval of time, the error would increase to the point that the person in question would no longer be the same person as they were at time zero. However, given any positive, non-zero acceptable error, then there would exist a small localization of time in which this person was the same person. So, in the experience of the person, they feel as if they are the same continuous person from one moment to the next. Yet, eventually over time, even they will come to the realization that they have changed in some way, and therefore are not technically the same physical person. This in turn leads them to jump to the conclusion that something non-physical must exist, although this assertion does not actually follow logically form their experiences.

In addition, physicalism can account for the appearance of mind-body interaction by simply stating that there is no non-physical mind and the appearance of one is simply an illusion. The mind is solely dependent on the existence and functionality of a person’s brain. Never in the recorded history of man has a person lived without at least a portion of their brain or brainstem. Although this does not rigorously prove that the mind is the material brain and not some sort of non-physical entity, it does make it easy to believe that this is the case. Often, one will raise questions as to how this is true since casual reflection can lead to the conclusion that one has a mind and that nothing physical seems to be taking place during the thought process. For sake of argument, let us agree that nothing uniquely physical is happening in one’s brain during a particular thought. Then what is it like when a unique physical procedure is occurring in the brain? Science has shown that our brain states are unique to mental conditions. So, is there a time when one can feel the physical differences in our brain? In the experiences of the author, the answer to this question is “No.” One never feels the physical changes in his or her brain except through the mental changes they cause. Therefore, though you have a memory without the sensation of a physical process, it does not follow that such a process is completely absent. In other words, we have always been “trapped” inside of our physical brains and do not know what it would be like to have mental thoughts without the physical changes occurring inside of us. So either we have a mind and cannot imagine what it would be like to have only a physical brain, or we are unable to grasp true non-physical actions and yet have a physical brain which we falsely assume interacts with a non-physical mind. From the view of science and the arguments above, the latter choice seems more appealing.

Another concept that physicalism can describe is the experience of subjectivity. Since we each are unique piles of atoms with unique arrangements, it would follow that we would experience our lives different from other people. The arrangement of neurons in our brain defines the way we perceive the world. If we did not have our collection of sensory connections or the exact neural network structure in our brains, not only would we experience the world differently, we would not even think the same or even be the same person. This is why asking the question “What is it like to be something else?” is a nonsensical question. There is nothing it is like to be anything other than what you truly are. Either you are that thing or you are not that thing. The reason one cannot adequately explain the world as they see it is a result of the shortcuts we try to make through language. Instead of saying, “I had an emotion,” person A could say, “Sections C thru F of cerebral network 91 and 176 fired first, followed by sections Q and K of networks 133, 256, and 90, in this diagram here that represents the ever-changing neural connections of my brain.”  And if person B was able to understand the diagram, reconstruct part of his or her brain to mimic the aforementioned actions, and then allow this part of his or her brain to run its mock program, person B would completely understand the so-call subjective statement of person A.  Sadly, such a procedure and extensive knowledge of our own brains does not exist in current technology and so we are left to express our subjective feelings in a very arcane use of verbal language.
Similarly, free will is also described as an illusion in the physicalism theory. Why we think we have free will is a combination of two separate phenomena. First, we cannot become aware of notions that reside in our subconscious minds that were caused by influences from the past. In addition, we are not conscious enough to be aware of every little thing that is immediately influencing us. Most information bypasses the conscious mind and goes straight to the subconscious. The second factor stems from a weird sense of human pride. For some odd reason, a large percentage of people develop the idea that they are special and unique. They feel as if they, as members of the human species, are better than all other forms of life on the planet. So in order to back up this egocentric idea, they claim that there is some part of their being that can go against the laws of causality and produce a truly free volition. Clearly, such persons have no way of supporting their claims except be asserting that there exists a non-physical, causality-independent part of them that is undetectable be any known methods. Physicalism forgoes this nonsense and recognizes the personal ignorances that we all have.

In conclusion, physicalism is the better theory to explain the facade of free will, the apparent mind-body interactions, the experience of subjectivity, and the perceptible continuity of personal identity through time. Even though no rigorous proof exists to show that physicalism is the correct theory, it is just as impossible to form a proof that physicalism is not correct. Although this does not readily mean we should take it to be the absolute truth, considering our short time on Earth, we should address physicalism as the best idea so far.