withallyourmind.net

    In Part I of my brief series on issues of interest in the philosophy of mind, I gave a modal argument for substance dualism by appealing to the conceivability of being disembodied or having a different body. In this post, I’d like to look at a central aspect of consciousness and show why many philosophers don’t believe it can be reduced to the physical.
    Phenomenological properties, now most commonly known as qualia, are “what it’s like” properties. What I mean by this is that for each of our sensory experiences there is a “what it’s like” quality. For example, seeing a red rose in bloom has a distinct sensory quality that is quite different from that of seeing a yellow sunflower. Similarly, the smell of gasoline has a quality that is different from smelling a bar of Dove soap and the caress of a loved one feels quite different than the prick of a pin. It is these distinctive “what it’s like” properties that philosophers refer to when they speak of phenomenal consciousness or qualia.
    Many philosophical arguments have been given in recent years that such properties cannot be physical properties and they have convinced even some of the most die-hard physicalists to admit the reality of at least some things that are outside the physical domain (See the earlier discussion of Jaegwon Kim’s latest book). This first is called the knowledge argument and can be summarized in this way:

Suppose it is sometime in the future, say 2560 and there is at this time a surgical operation that can fix colorblindness. Suppose furthermore that there is a prominent scientist who is in her 40s and is colorblind and is yet to recieve this operation (let’s call her Martha). Martha, it just so happens, studies physics and neuroscience and in fact knows everything there is to know about the physics and and physiology of seeing, for example, the color red. She can describe in complete physical detail everything that happens when light reflects off of a red object, interacts with the eyes, optic nerves, brain, etc. Suppose that she then gets the operation to cure her colorblindness and the first thing she comes across when taking the bandage off of her eyes is a red object. Does she learn anything new at that point? It seems obvious that she would, namely, what it is like to see a red object. But we already assumed that she knew all the physical facts about what it is to see red. Therefore, there must be some facts that go beyond the physical.

    Thomas Nagel famously argued that this is because some facts can only be captured from a “subjective perspective,” which don’t play any role in the objectivity of science. For example, we can know everything there is to know about a bat from the objective perspective and still be missing factual information. Even if we know to the most minute detail everything physical that goes on in a bat’s sonar system, we will still be missing something, namely, what it’s like to perceive an object using sonar.
    Another famous argument is David Chalmer’s zombie argument. Physicalists have long held to the supervenience of the mental on the physical. This means that for any mental state M, there is a physical state P such that M supervenes on P and that if any x is in M x is alo in P and vice versa. This has usually been portrayed as a necessary connection, but Chalmers argues that it is not. For, he says, it is conceivable (and therefore probably possible) that there is a zombie world that is physically indiscernible from our own but in which no one has phenomenal consciousness.
    If this is true, what it means is that there is no necessary connection between physical states and (phenomenal) mental states and physicalists are not only left with something outside of the physical, but something that leaves a large explanatory gap. Why is it that when I am pricked with a pin I feel a pain rather than a tickle? Why is it that an apple tastes sweet instead of sour? If these can not be reduced to anything physical, then it seems no scientific explanation of them can be given . Some philosophers have used this point to argue that a personal, non-physical explanation must be given (A.K.A. God - see Robert M. Adams’s Flavors, Colors, and God).
    Although these arguments do not prove substance dualism I do believe that they have implications for it (which I will perhaps spell out later). What is more important is that they show fundamental problems with any strictly materialist philosophy of the mind, something that I think Christians should be happy about.