262 NONMONOTHEISTIC CONCEPTIONSArguments against dualism
There are widely accepted arguments against dualism. One such argument
contends that materialism is simpler, positing less kinds of substance,
though why having two sorts of material substance, one capable of self-
consciousness and one not, is in any significant way simpler is as unclear as
why appeal to simplicity of kinds of substances should carry the day (or
favor materialism, since idealism is simpler than dualism in the same sense
as that in which materialism is). The most frequent criticism is that the
only version of dualism that is plausible is interactionism, the position that
mental events cause physical events and physical events cause mental
events. But mind–body interaction, we are told, is impossible – how could
such different things as an immaterial substance and a material substance
interact? This is perhaps the only time in contemporary philosophy in
which the causal likeness principle is invoked – the claim that in order for
X to affect Y with respect to some property Q, X must have Q or something
like Q. There is neither criterion for what degree of similarity is required
nor reason to accept the principle. Dualists find it unclear why color
experience being caused by non-colored things, colds and flu by bacteria
and viruses, pain by unfeeling things, and the like somehow are
unproblematic whereas mind–body interaction is problematic.
It seems that the basic reason for the rejection of dualism as a live option
in much of contemporary academia has to do with what might be called the
mapping problem: how does one relate the description of the physical
world, insofar as we can provide this, to the descriptions true of everyday
choices and actions? Roughly, how does one map our descriptions of the
mental world onto our descriptions of the physical world?
It is tempting to deny that there is a mapping problem by suggesting
that our descriptions of the physical world, cast in natural science terms,
and our descriptions of persons and their freedom of thought and action,
are incommensurable in the sense that they do not bear logical relations to
one another – that they do enter into relations of consistency,
inconsistency, entailment, and the like. The problem is that the suggestion
is false; given that a description of the physical world is true, there are
hosts of actions not available that would be available were the physical
world otherwise. For example, if the correct description D1 of the physical
places an orange at place P at time T, then at T it is not possible to bring the
orange to P – it is already there. If the correct description included the
information that the orange was elsewhere than P, bringing it to P would
(given other features of things) be possible. In such ways, and much more
complex ones, what makes a particular description of the physical world at