In arguments against the physicality of mind, the subject of qualia often comes up. Qualia are direct experiences unmoderated by interpretation--the experience of seeing the color red, what it is to be a bat, and the like. Qualia are experiences which are ineffable (inexpressable and not communicable), intrinsic (self-contained and not dependent upon other knowledge), private (we cannot compare them), and immediately apprehensible (if you have the experience, you know it, and you know everything there is to know about it.)
Most of the arguments for qualia and against the physicality of the mind employ thought experiments which slip in the assumption that no physical change has been wrought in the body or brain by the experience, effectively assuming the consequent; we assume no physical basis for the experience, and presto, there is no physical basis! The inverted spectrum and zombie thought experiments are examples of this. Others hinge on the idea that qualia are inexpressable--but this says nothing about qualia, and much about the limitations of language. In any case, one would expect that a purely idealized form of expression would be ill suited to describing purely physical phenomena--these arguments actually support the physical basis of mind and experience, rather than weaken it. To be a bat, to see a color, or to have any direct experience is a physical event, involving deep underlying experiences involving sensory organs, muscular/skeletal sensations, and so on. Choreographers are still seeking a notation for dance which can express even the most basic repertoire of movements. Imagine trying to describe not only the movements in detail, but the detailed experience of performing them! And yet, there can be absolutely no doubt that these are physical actions and sensations.
In fact, qualia are the most physical aspect of consciousness. In discussions of the ineffable, mystical insights are usually regarded as the ultimate ineffable experiences. But how do these often come about? Through extreme conditions of the body--fasting, exertion to the point of collapse, drugs, the deliberate self infliction of pain, or repetitive or long held postures or activities. These experiences are commonly induced through direct or indirect manipulation of neurochemical states. Yet the claims of mysticism are that one has overcome the body, when in fact they have manipulated their bodies to achieve these states. Even the most spiritual of experiences is, at its very roots, physical.
Steven Pinker, in a recent article regarding The Stupidity of Dignity notes that Leon Kass, who loaded a council on bioethics with staunch Catholics, regarded any physical act, even eating, as undignified--Kass railed against the indignity of eating ice cream cones in public. Likewise, Kass exalts the imagined spiritual properties of an ovum over the physical good of living people. His sympathy with Catholicism is all too clear; Catholicism too values the mortification of the flesh and the exaltation of spirit. But this is simple vanity; a disgust with the limitations of human physicality in comparison with the exalted qualities of imagined gods and perhaps even with more perfect human specimens, a desire to be perfect, ideal in a Platonic sense, a resplendant being of light who does not fart or fuck or belch. A belief in spirit detached from the physical invites the hatred of life in all but principle, as all but stepping stone to the afterlife. The love of spirit becomes a loathing for humanity.
Finally, there is a claim that qualia are the most meaningful and significant of all experiences. The title of this post suggests the opposite. People that I have met who were veteran drug users are in the habit of making statements like "It's really a something!" "He's really doing something." "He's doing his scene." What do these statements mean? Nothing. They are utterly devoid of content, because they refer to the type of drug experiences in which the person is unable to integrate the experience. The tragedy of the youth drug culture is that, unlike the first pioneers of psychedelics, who were usually well versed in science, philosophy, literature, and mysticism, barely literate teenagers have no frame of reference. All they can say is "Wow!", and in retrospect, one wow is very much like another. These are raw qualia, but until they are drawn into the world of expression and related to other experience and knowledge, they remain physical noise. Qualia must cease to be qualia to acquire meaning. Only then do they properly become aspects of consciousness rather than the signals of the autonomic nervous system. Furthermore, it should be immediately apparent that, having been caused by a chemical, these experiences--which often approach the mystical--have an entirely physical basis.
There is a particular style of philosophical discussion which is properly called "nonsense on stilts"--discussions of things which neither refer to facts about the real world (do not touch the ground) nor involve precisely defined terms (nonsense). I suspect that metaphysics has not gained any ground since the ancient Greeks. It is not that they gave the final answers; they may not have even asked the right questions. The same arguments run back and forth without any resolution in sight, revolving around the definitions and redefinitions of vague words and concepts. These are language games. Some philosophers were so caught up in these games that they decided that all human interaction consisted of nothing more than language games, forgetting that most people actually devote most of their time talking about real things and events in the physical world. They had become so divorced from reality that they decided it did not exist. But any subject which does not bow to carefully gathered fact, or which does not restrict itself to concepts of near mathematical precision, will soon find itself building castles in the sky, to be cast down and raised again by whims of opinion. This is not knowledge, nor any way to achieve knowledge. This is mere sophistry. The stagnant condition of metaphysics and theology suggest that these disciplines are in precisely this rut.
When I first encountered metaphysics as a young undergraduate, it was my favorite topic. I thought I had discovered magic, a means of unraveling the secrets of the universe without ever being forced to learn about the world. Through the simple exploration and combination of vague concepts I could understand, and perhaps even affect, the world. I wonder how much of this still animates enthusiasm for metaphysics, and for non-physical explanations of reality. If consciousness is non-physical yet can still influence reality, then perhaps one can do away with the whole bother of moving and exploring, avoid death, even avoid the physical disciplines of the mystics required to attain peace of mind. It is this aspect of wishful thinking most of all that makes arguments for non-physicality suspect.