Physicalism is the view that everything is physical. Every thought, mental state, etc. we experience is reducible to physical explanations. It can be said, according to physicalism, that neurons firing or chemicals being released are an emotion or mental state.
I believe physicalism can be rejected on the grounds of unintelligibility. One reason for this is that physicalism forgets the idea of causation. It equates a cause with an entire process. One can agree that there are physical causes for a mental event, but does not have to accept that this means that a mental event itself is physical. An emotion is not a firing of a neuron or some amalgam of chemicals. Mental states are described from a first-person subjective viewpoint, and cannot be equated with the physical world, which is described in physical terms.
The most commonly used argument for physicalism is the “argument from causal closure”:
–“If an event e causes event e*, then there is no event e# such that e# is non-supervenient [edit: supervenient generally means dependent] on e and e# causes e*.” (Stanford Encyclopedia of Philosophy).
The problem with this view, of course, is that it can be countered by simply rejecting premise 2 “there is no event e# such that e# is non-supervenient on e and e# causes e*.” One can simply point out that it is possible for there to be an event e# to exist.
Further, what exactly does it mean to say that mental states are wholly physical? I believe that is ontologically untrue. One can simply examine one’s own thoughts and realize that, say, thinking about a pink elephant is not ontologically a pink elephant. Physicalists would have to try to describe this mental image wholly in physical terms, for that is all there is to the world according to their methodology. But it is then almost impossible to distinguish between the image of a pink elephant and the pink elephant itself. Try that thought experiment. Describe yourself “thinking about a pink elephant” in wholly physical terms. Do not slip into saying such words as “mental state”, “mental”, “thinking”, “I”, and the like. It may be possible, but it ends up being something utterly ridiculous which doesn’t seem to really describe the event (thinking about a pink elephant) at all. It describes the things that are causing one to think of a pink elephant.
Physicalism also leads inevitably to determinism. If all things are wholly physical, there cannot be any kind of freedom of the will. All things are determined by physical processes, meaning there is simply no individual to possess freedom.
Physicalism can be faulted for either not adequately explaining or completely rejecting: mental states, the will, individuals, liberetarian freedom, freedom of permission, freedom of personal integrity, and freedom of moral and rational responsibility.
What exactly does it mean, within physicalism, to have the “want to do something?” For example, I am moving my things from one room to another. I want to lift up and move my couch on my own, but I cannot. Physicalism does not seem to have an adequate explanation for this. Wanting to do something could be causally linked to certain parts of the brain showing activity, but it could not explain the desire itself.
What would it mean if, say, a scientist could monitor the brain and know every thing a person was thinking about? Imagine being able to do such a thing. Looking at a screen, one could see that a person could think about a “dog” and one would not actually know what that person is thinking. Or, perhaps the technology is such that the dog which the person was thinking of would be entirely described. It’s a black lab the person owned in his or her childhood, it has a scar on its nose from a fight with a cat, its fur has a bluish sheen in certain light, etc. It still does not mean that one could literally read this person’s mind. For the mental image of a black lab, down to the tiniest detail (i.e. fur length, etc.) will be different from one person to the next. Even if we could literally think of every detail, including the length of each individual hair on that lab, etc., the mental image we had would be different, for we all think of such details in different ways. Descriptions of colors, scents, sounds, etc. vary widely from person to person.
But then, what if we could project an image onto the screen of that dog, in every detail? Two things would prevent this from allowing an identical image: 1. any emotional attachment to the image, and 2. the subjective interpretation of sensory imagery.
Another way to try to explain this scenario into possibility for the physicalist would be to say that technology could allow us to transfer that image, with its emotion, etc. into someone else’s mind. But then, we still have problems. 1. Even if we could project the exact image, along with it’s emotional responses, into someone else’s brain, that person’s brain would still interpret that image for itself. It would be presented with certain emotional states, sensory details, etc., but it would be filtering all of those through its own system. 2. There’s no clear way to say that even if we could eliminate problem 1, the image would be exactly the same with both people.
Even if one could project all the emotion, history, details, and the like of an image from one person to the other, it would not be the same. Why not? Because of another problem with physicalism: emotional states are not the same. What one person experiences as pain can be entirely different for someone else. Let’s say that, sticking with the black lab, subject A has a positive experience of this animal. This brings with it the feeling of pleasure at recalling the image, and calmness related to feeling protected by the dog. When it is projected into the brain of subject B, these emotions may not be the same. For even if one could capture the intensity of these feelings, there’s no way to say that the conotations they’d carry would be the same. Subject B would have pleasure related to recalling the image projected into his or her brain, but this pleasure would have to be intepreted by Subject B before it was presented as an image. The pleasure could feel different from subject A to person B, despite the exact same physical processes involved.
But what if we could project literally every aspect of this image into someone else’s mind (from person A to B)? What if we could somehow get past the interpretation problem? Would this then prove physicalism has weight? I don’t believe so. The problem here is threefold: 1. The problem of “self” in regard to the image. If the image were projected in such a way from person A to B, would it then be person B’s thought/image or would it still be person A’s, just projected into another brain (or mind)? For physicalism to be true, the image would have to be person B’s and identical to person A’s, but it seems like this is not the case, both by the nature of the whole experiment and by the fact that the image exists within person A’s brain originally. Not only that, but 2. it ignores the fact that there is such a thing as the image itself. Even if 1. were not a defeater of physicalism in this case, it seems to be defeated by the fact that the image is itself not made itself all the factors that go into making the image, but is simply an image. The image itself is different from the causation. There is not a black lab within someone’s brain. There is the image of this black lab within their brain. The fact that it must be discussed in such terms goes against physicalism. Cause is not equal to effect. 3. If this entire scenario were about an image that was imagined in person A’s head, rather than a real black lab he or she owned, it runs into a whole host of other problems. What does it mean to have something that doesn’t actually exist, existing in two people’s brain/minds? How is it that physical explanations give rise to a non-physical thing (something that is imagined does not exist physically, so it does not have physical space, qualities, etc., and cannot therefore be reduced to physical qualities, as it does not posess any)?
The point of this scenario is to point out that physicalism discounts some of the most self-evident qualia we experience. Physicalism cannot account for such differences in pain, pleasure, and other feelings or emotional states. It cannot account for the differences in experience when the physical causation is the same.
Point 3. has in it yet another blow against physicalism. What of imagined things? It seems possible that we could physically explain how we bring forth the image of something that is imagined (such as a flying pig), but that does not explain in physical terms what exactly that imagined thing is. What is it, in terms of physicalism? It is not real or physical, so how can it be reduced to something physical? And we certainly cannot say the image does not exist, because anyone with an imagination can think of a flying pig! But even if we were to assign it physical properties (i.e., wings, pigs feet, curly tail, etc.), it would not actually possess any of these. It is something that simply does not exist physically, and it would beg the question to assign it physical properties.
Ontologically speaking, physicalism seems shot full of holes. It can be simple to talk about all mental states, images, and the like as if they were merely physical, but in the real world, does it really mean anything to say that? It is evident from one’s own experience that one can think in terms of self, in terms of intentionality, and in terms that defy physical explanation. What does it show to say that such things don’t actually exist? It makes our personal experiences meaningless.
It is unintelligible to embrace physicalism, for it means nothing to say that our “self” is not a “self” but a mixture of physical explanations. It means nothing to say that our emotions don’t exist except in physical terms. It means nothing to say that the mind is not a “mind” but a physically reducible thing. It means nothing to say that imagined things don’t exist (they exist within the brain [or mind] of anyone with an imagination), and it begs the question to say that they possess physical properties.
Physicalism, at best, can serve only as a causal explanation of mind states, mental images, and the like. Yet the thesis itself claims to have superior explanatory power in that it can explain everything (via physical means). Finally, physicalism has inadequate explations for, or outright rejects, things that are evident simply through introspection (imaginary objects, the concept of “self,” etc.). Its claims about such things are either meaningless or unintelligible. I therefore reject it on the grounds of unintelligibility.