Mind is explained as function patterns. Mental states are defined in terms of their functional roles in relation to other mental states and the environment. Although function patterns require physics of realization, any particular physics are inessential. Minds can be realized in brains or other machines using materials that can maintain adequate function patterns. But it is unclear how such function patterns would explain consciousness. It is also unclear how to delineate the mental from the nonmental, if we take functionalism seriously. A thermostat functions as if it knows how to regulate heat, but does it really know? Some functionalists would say that it does indeed know. Most of us would probably say that it doesn’t really know anything or have any mental states—why should we think so? Overall, the approaches associated with materialism, in its common forms, do not adequately explain how we are to understand consciousness.
After thousands of years of thinking about the mind, and battles between positions, we still have no agreement on how to understand the conscious mind in nature. This is why McGinn waves his white flag.