Supervenience, Materialism, and Skepticism: Critiquing Some Key Epistemological Underpinnings of Chalmers" Dualistic Philosophy of Mind

David Chalmers has recently received much attention for
arguing against a materialistic theory of mind and for a
type of property dualism (see Chalmers 1996). So what
exactly is a materialistic theory? According to Chalmers,
materialistic theories require, roughly speaking, that all
facts, including macrolevel facts, either are microphysical
facts or supervene logically on microphysical facts (Chalmers
1996, 41, 128). For instance, biological facts logically
supervene on basic physical facts. But how does Chalmers
understand supervenience? After explaining the basic idea
and discussing some technical problems, he provides the
following gloss: "[supervenience is] a thesis about our
world (or more generally, about particular worlds)...
According to ... [this] definition, B-properties are logically
supervenient on A-properties if the B-properties in our
world are logically determined by the A-properties in the
following sense: in any possible world with the same Afacts,
the same B-facts will hold" (Chalmers 1996, 39).1
Utilizing many creative examples invoking objects such as
zombies, he contends that mental phenomena, and conscious
experiences in particular, do not supervene on
material states of affairs. Consciousness, then, is unlike
just about every other natural phenomenon, which does
supervene on materialistic states of affairs. Hence consciousness
is special, different, and, in accord with his
dualism, separate.