All Machine and No Ghost? the More We Look at the Brain, the Less It Looks like a Device for Creating Consciousness. Perhaps Philosophers Will Never Be Able to Solve the Mystery
McGinn, Colin, New Statesman (1996)
The philosophy of mind is concerned with fundamental questions about consciousness - about its existence and nature. The science of psychology is concerned with its empirical workings - how one mental thing leads to another, basically. The former is a branch of metaphysics, the latter of dynamics. The central defining property of the mind is consciousness, so philosophy of mind is concerned with the existence and nature of consciousness; what is consciousness, why does it exist, how is it related to the body and brain, and how did it come into existence?
These are big, difficult questions. Focus on your current state of consciousness - your experience of seeing, hearing, feeling, thinking, willing, and so on - and ask yourself what kind of being this consciousness is, what its function might be, how it is related to the activity of cells in your brain, what could have brought it about in the course of evolution. Allow yourself to feel the attendant puzzlement, the sense of bafflement: now you are doing philosophy of mind.
Try to imagine a world with no consciousness in it, just clashing quanta in the void and clumps of dead, insensate matter (the way our universe used to be); now add consciousness to it. What difference do you make to things, what is the point of the addition and how can you add consciousness to a world without it? Do you somehow reassemble the material particles? I predict it will seem to you that you have made an enormous difference to your imagined world but you will not understand how the unconscious world and the conscious world fit intelligibly together. It will seem to you that you have performed a miracle (contrast adding planets to a world containing only gaseous clouds). But does our world really consist of miracles?
We can distinguish five positions on consciousness; eliminativist, dualist, idealist, panpsychist and mysterianist. The eliminativist position attempts to dissolve the problem of explaining consciousness simply by declaring that there isn't any: there is no such thing - no seeing, hearing, thinking, and so on. There is just blank matter; the impression that we are conscious is an illusion. This view is clearly absurd, a form of madness even, and anyway refutes itself since even an illusion is the presence of an experience (it certainly seems to me that I am conscious). There are some who purport to hold this view but they are a tiny (and tinny) minority: they are sentient beings loudly claiming to be mindless zombies.
More subtly, there are many who insist that consciousness just reduces to brain states - a pang of regret, say, is just a surge of chemicals across a synapse. They are collapsers rather than deniers. Though not avowedly eliminative, this kind of view is tacitly a rejection of the very existence of consciousness, because the brain processes held to constitute conscious experience consist of physical events that can exist in the absence of consciousness. Electricity in the brain correlates with mental activity but electricity in your TV presumably does not - so how can electrical processes be the essence of conscious experience? If there is nothing happening but electrochemical activity when I say, "My finger hurts," or, "I love her so," then there is nothing experiential going on when I say those things. So reduction is tantamount to elimination, despite the reductionist's intentions (it's like maintaining that people called "witches" are nothing but harmless old ladies - which is tantamount to saying that there are no witches).
The dualist, by contrast, freely admits that consciousness exists, as well as matter, holding that reality falls into two giant spheres. There is the physical brain, on the one hand, and the conscious mind, on the other: the twain may meet at some point but they remain distinct entities. Dualism may be of substances, properties, or even whole universes, but its thrust is that the conscious mind is a thing apart from, and irreducible to, anything that goes on in the body. …