who wish to challenge the multiple realization of psychological properties sometimes
suggest that it is more likely that a more general property, such as being in
pain, is multiply realized than it is that a more specific property (of that
general kind), such as human pain, is multiply realized. There are more ways to make a powerful engine
than there are to make a powerful V8 engine.
There are more ways to make a powerful V8 than there are to make a 350
hp V8. The finer the grain of
description, the more constraints there will be on the modes of construction, hence
the fewer realizations there will be.
a view, however, does little, by itself, to undermine the view that
psychological properties are multiply realized.
For one thing, this leaves open at least the possibility that there are
scientifically legitimate general properties, such as being in pain, and that
they are multiply realized. For another,
it leaves open the possibility that even the fine grained, specific properties
are multiply realized, even though this is less likely than it is for general
properties. After all, we know that there
are many ways to design a 350 hp V8. Different
cylinder displacements, different compression ratios, different fuels can be
used to make such an engine. Returning
to the example of pain, even if pain is more likely to be multiply realized
than is human pain, that leaves open the possibility that human pain itself is
multiply realized. Something stronger is
needed to press this kind of challenge to the multiple realization of