Bruce Buff and Robert J. Spitzer write:
But when it comes to the mind, this idea [i.e., emergence] has its issues. First, all scientifically observed emergence is actually unanticipated behavior resulting from known physical properties, and not new properties that exceed what physics can explain. Some materialists suggest that consciousness might emerge from physical processes on the quantum level, but any emergence there would be disrupted by anything that has an effect on quantum physics — such as holding up a cell phone to your head or getting an MRI. Simply put, emergence depends on properties that already exist in the system’s constituent parts. It doesn’t matter how many Legos are assembled in incredibly complex arrangements, they will never generate a nuclear reaction. Just as radioactivity cannot emerge from the plastic used in the blocks, consciousness does not emerge from the physical parts of the brain.
Precisely. Think about all of the usual examples of emergence: hurricanes, schools of fish or flocks of birds acting in unison, the wetness of water. Now think about what makes all of these examples absolutely irrelevant to discussions of consciousness. In the former, as Buff and Spitzer observe, known physical properties act in unexpected ways. For example, the atmosphere acts in unexpected ways to form a hurricane. Yes, it is extremely complex, but we can see how, in principle, the strong winds, lowered barometric pressure, etc. can be reduced to physical causes.
Not so with mental activity. While no one denies there is some connection between a person’s mental state and his brain, it is nevertheless absurd to suggest that subjective-self-awareness, intentionality, qualia and other features of consciousness can be reduced to the electro-chemical reactions in the brain. “Mental” and “Physical” are self-evidently in different ontological categories.
It follows that a claim that the mental is somehow an emergent property of the physical is a non-starter as any sort of explanation. It is, as has often been observed, a confession of profound ignorance masquerading as an explanation. It is, nevertheless, a sufficient “explanation” for the already-convinced true believers of materialism. Those of us of a more skeptical bent see a distinct lack of threads on that kingly body.