Philosopher David Chalmers argues that any version of physicalism cannot provide an adequate explanation of consciousness and how we have both mental states and physical states. In his essay Facing Up to the Problem of Consciousness, he distinguishes two different problems of consciousness as the easy problems and the hard problems (Chalmers 1995; 1-2). The easy problems are in explaining phenomena such as reportability of mental states, the focus of attention, the deliberate control of behavior and so on. He believes that this can all be explained scientifically and that the explanations for these can be reduced. We can explain the functionality of these phenomena (Chalmers 1995; 4). The hard problem on the other hand is a problem of how we come to have experience. The problems of consciousness that are considered hard problems cannot be adequately explained by scientific methods. For Chalmers, experience of the world is synonymous with qualia. He thinks that the hard problem is in how we explain how we have an experience of color or an experience of anything at all. Chalmers asks the question, “why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does” (Chalmers 1995; 3). The basic functions of the brain can be explained in reductive terms but the experiences cannot. Chalmers says there is an explanatory gap between the physical functions and conscious experience and we need an explanatory bridge in order to overcome this gap (Chalmers 1995; 6).
Chalmers proposes five strategies researchers in neuroscience and philosophers can take in approaching this explanation of consciousness. The first is to explain something other than the hard problems of consciousness. This strategy doesn’t really do much to forward our knowledge about how to come up with a bridge. It stays on the “easy” side of the gap (Chalmers 1995; 9). The second way is be an eliminativist about consciousness and deny its existence. Chalmers thinks that this is quite absurd and seems to be assuming a type of verification principle. He says that “a theory that denies the phenomenon ‘solves’ the problem by ducking the question” (Chalmers 1995; 9). A third option is for researchers to explain consciousness in the full sense, yet Chalmers thinks theories that which go for this option are nearly magical. This strategy doesn’t explain how consciousness emerges (Chalmers 1995; 9). A fourth approach seeks to explain the structure of experience. By explaining the visual structures in the brain one can explain how that relates to color. This strategy would still amount to staying on the “easy” side of the gap as opposed to actually building a bridge between the hard and easy problems (Chalmers 1995; 10). The last method is to “isolate the substrate of experience.” This method tries to “pick out” which process accounts for experience. This is still an inadequate strategy because we need to know why and how the process gives us consciousness. Chalmers parts ways philosophically with these five strategies because he thinks we need an “extra ingredient” to give us an adequate explanatory bridge (Chalmers 1995; 10). Given that all of the reductive explanations fail, we need a nonreductive explanation. He argues that “a nonreductive theory of experience will add new principles to the furniture of the basic laws of nature.” This theory adds properties as being fundamental (Chalmers 1995; 14). He admits that his position is a form of property dualism – what he calls naturalistic dualism.
Before we look at the arguments that Chalmers advocates for property dualism, we need to first make a few distinctions between different types of consciousness. When people talk about consciousness, invariably it seems like they’re talking about one thing. All the definitions of consciousness appear to be lumped together into one concept. Philosopher Ned Block thinks this is a misinformed notion and that there are different types of consciousness. Having a conceptual framework as to what consciousness is will help us tackle the problems of consciousness with more clarity and precision. Block’s first distinction of consciousness is phenomenal consciousness or what he likes to call P-consciousness. P-consciousness is the state of “what-is-it-like-ness” (Block 206). This type of consciousness is experiential. It is just one type of consciousness we have. This type of consciousness includes “properties of sensations, feelings and perceptions… thoughts, wants and emotions.” These properties are distinct from functional and cognitive properties of the brain (Block 206-7). Another type of consciousness is access consciousness or A-consciousness. “A representation is A-conscious if it is broadcast for free use in reasoning and for direct “rational” control of action (including reporting)” (Block 208). This A-consciousness is a direct awareness and form of reasoning in the mind, while P-consciousness is just states of experience or feelings.
This distinction can help us understand the easy and hard problems of consciousness with more clarity. The easy problems of consciousness are related to Block’s A-consciousness. They are forms of consciousness that we use to focus, control our behavior, and so on. This type of consciousness is still a form of consciousness. It isn’t any more or less important. The hard problem of consciousness would be problems of P-consciousness. Finding an explanatory bridge to the question “what is it like to be such and such” is a much harder question then seeing how the brain functions with forms of A-consciousness. It is with these conceptions in mind that we now will look at three arguments that Chalmers puts forth that will motivate people to a form of property dualism. It is careful to note that these arguments have type-type identity, and functionalism in its sights. They are arguments that seek to show the falsity of physicalist identity theories or notions of functional properties supervening on physical and mental states.
In his essay Consciousness and Its Place in Nature, David Chalmers considers two important arguments establishing that physicalism is false because it cannot explain the full scope of consciousness. The first argument is a conceivability argument. Chalmers asks us to imagine that there be a being that is physically identical to us. This being has all the same brain properties and brain states. If you scanned their brain everything would check out as being identical to our brain structure. These entities would even have access consciousness and would be able to be awake, report the contents of his internal states and so on (Chalmers 1996; 95). But, as it turns out, they lack any phenomenal conscious state. This entity is called a philosophical zombie. Unlike the zombies in movies and television, these zombies appear to be exactly the same as humans – in both behavior and on a neuronal level. They have absolutely no inner feel and do not have any experience of the world. If you were to ask them if they are conscious, they would tell you that they are. Chalmers states the argument as follows:
- It is conceivable that there be zombies.
- If it is conceivable that there be zombies, it is metaphysically possible that there be zombies.
- If it is metaphysically possible that there be zombies, then consciousness is non-physical.
- Conclusion: Consciousness is non-physical. (Chalmers 2003; 6)
These zombies are the same as us in regards to A-consciousness but are not the same as us in regards to P-consciousness, to reiterate Block’s distinctions. Chalmers is concerned with phenomenal zombies (Chalmers 1996; 95). Now it has to be said that much of this argument either succeeds or fails with premise (1). Conceivability is used to generate possibility. If I can conceive of X, then X must at least be possible. It is important to note that this phenomenal zombie might not in-fact be able to exist in the actual world. There might be physical limitations to this existing in our world. But, it does seem that these zombies can exist in at least some possible world, merely because they are conceivable. There doesn’t seem to be any contradiction in the idea of phenomenal zombies. It is a coherent idea. Chalmers argues that some burden of proof lies with the person who wants to argue that zombies are logically impossible (Chalmers 1996; 96). He gives a different example of the idea of a mile-high unicycle which he thinks is also a possibility. He says that if “a mile-high unicycle is logically impossible, she must give us some idea of where the contradiction lies, whether explicit or implicit” (Chalmers 1996; 96). The same burden falls on the person who wants to deny zombies. This argument shows that consciousness does not metaphysically or logically supervene on the physical and that consciousness must be non-physical (Chalmers 1996; 97). The phenomenal properties can differ without a difference in the physical properties and thus the phenomenal properties do not metaphysically or logically supervene on the physical properties.
Maybe the zombie argument is not convincing for a functionalist or a type-type theorist. Consider another argument of the inverted spectrum. The argument relies on some of the same intuitions as the zombie argument but the intuitions are much more localized. The zombie argument considers the whole physical identity of an entity with respects to phenomenal consciousness, while the inverted spectrum argument considers the function of the visual color spectrum and how it relates to experience. It seems possible that you can have two people who are identical to each other yet one of them has an inverted color experience. Person X has properly functioning vision (his brain is ordered in the proper way) and picks out apples, firetrucks, and strawberries as being red objects. This person experiences red. Person Y, on the other hand, picks out these same objects as being red, yet has the experience of green. Person Y has inverted vision. How can this be possible? It seems possible that we can change the brain structures in such a way to have this inversion. This argument is successful at showing that the function of person X can be completely identical to the function of person Y and yet both lead to two totally different experiences. If the functions are the same, why are the generated experiences fundamentally different? “Somebody might conceivably hold that inverted spectra but not zombies are logically possible. If this were the case, then the existence of consciousness could be reductively explained, but the specific character of particular conscious experiences could not be” (Chalmers 1996; 99-101).
Let us consider a final argument known as the Mary Argument. This argument involves a thought experiment. Imagine a neuroscientist named Mary. She is the leading expert in her field when it comes to her knowledge about how color operates, how our eyes pick up the light from color, and how our brain functions during that process. She knows all the physical facts about vision and the brain. But, as it turns out she has been raised in a black-and-white room. She has never experienced color. We can imagine her opening the door and leaving the black-and-white world and going into the world of color experience. Since she has never had any experience of color before, her entrance into the colored world will add more information to her knowledge about vision and the brain. Prior to opening that door, she knew all the physical facts about color but, after opening the door she learned something new – the way it feels to subjectively experience color (Chalmers 2003; 7). As a helpful analogy, consider the movie The Wizard of Oz. Dorothy grows up and lives in a black and white world her whole life. Yet, when she enters the world of Oz for the first time she learns something new about subjective experience of color. The Mary argument is similar to this, but it is different because Mary has full knowledge of all the physical color facts. This argument can be put as such:
- Mary knows all the physical facts.
- Mary does not know all the facts
- Conclusion: The physical facts do not exhaust all the facts. (Chalmers 2003; 7)
This argument shows that we cannot gain all the facts of the world merely by having a list of all the physical facts. Indeed, Richard Swinburne says that a full history of the world must include public facts and facts in which we have private access to (in this case, Mary’s subjective experience of color) (Swinburne 67-70).
We have established that these arguments minimally lead to a form of property dualism and that these arguments give us an explanatory bridge for the hard problem of consciousness. I do not believe that one can consistently hold a view that resembles Chalmers’s view. Since I still maintain that the three arguments are successful, I think that one must embrace a form of substance dualism. I have briefly explained this view earlier, but let me reiterate it again. Substance dualism is the view that there are two distinct substances (mental and physical substances) with respective properties and that these two substances interact with one another. Another entailment of this view is that the self is essentially a pure mental substance and not a physical substance. I am now going to argue that property dualism motivates towards substance dualism and that property dualism has more problems than substance dualism. I will argue that property dualism has some conceptual challenges. Moreover, I will give a negative and a positive argument against a form of property dualism, specifically, Chalmers’s view. Lastly, I will briefly examine some metaphysical constraints that may or may not be beneficial in determining one’s metaphysical framework.
Block, Ned. “Concepts of Consciousness.” Philosophy of Mind: Classical and Contemporary Readings. New York: Oxford UP, 2002. 206-18. Print.
Chalmers, David J. The Conscious Mind: In Search of a Fundamental Theory. New York: Oxford UP, 1996. Print.
Chalmers, David J. “Consciousness and Its Place in Nature.” Papers on Consciousness. N.p., 2003. Web. Apr.-May 2015. <http://consc.net/papers/nature.pdf>.
Chalmers, David J. “Facing Up to the Hard Problem of Consciousness.” Papers on Consciousness. N.p., 1995. Web. Apr.-May 2015. <http://consc.net/papers/facing.pdf>.
Swinburne, Richard. Mind, Brain, and Free Will. Oxford: Oxford UP, 2013. Print.