nature can be physical, if you try to jump over too many intermediate
stages at once. For example, it can easily seem mysterious how a living
organism can maintain itself as an integrated whole, if we just focus on
the fact that any such organism must consist, ultimately, of sub-atomic
wave-particles governed by indeterministic principles, forgetting about
all the intermediate levels of description in between. And as we shall see
in section 3, the most plausible explanations of phenomenal conscious-
ness on the market arecognitivein nature, attempting to use some or
other functionally deWnable notion of state-consciousness to explain the
subjective qualities of our experiences.
But the second, and truly major, fault in McGinn’s argument is that he
ignores the possibility that we might succeed in closing the explanatory gap
between consciousness and the brain by operating with inference to the
best explanation on phenomenal consciousness itself. Indeed it is obvious,
when one reXects on it, that this is the direction in which enquiry should
proceed. For in science it is rarely, if ever, the case that we have to seek
higher-level explanations of lower-level phenomena. We do not, for
example, turn to biology to explain why chemical reactions work as they
do. Rather, we seek to understand higher-level phenomena in terms of
their realisation in lower-level processes. And no reason has yet been given
why this strategy should not work when applied to phenomenal conscious-
ness, just as it does elsewhere in nature. To adopt this strategy would be to
seek to explain phenomenal consciousness in terms of some postulated
underlying cognitive mechanisms or architectures, which one might then
hope to explain, in turn, in terms of simpler computational systems, and so
on until, ultimately, one reaches the known neural structures and processes
of the brain. While we perhaps have, as yet, no particular cause for
optimismabout the likely success of this strategy, McGinn’s sort of prin-
cipled pessimism seems certainly unfounded.
2.4 More explanatory gaps?Chalmers (1996) argues that almost all states and properties of the natural
world (with the exception of phenomenal consciousness, and of states in
one way or another involving phenomenal consciousness, including secon-
dary qualities such as colours and sounds) supervenelogicallyon the total
micro-physical state of the world. That is, he thinks it is conceptually
impossible, or inconceivable, that there could be a universe exactly like
ours in respect of its total micro-physical description, and sharing our
basic physical laws, but diVering in respect of any of its chemical, geo-
logical, geographical, meteorological, biological, psycho-functional, or
economic properties. For once the properties, position, and motion of
Mysterianism 239