Engelstalige samenvatting:

This book combines two topics. First, there is the claim that our folk-psychology
reduces to some future neuro-physiological or functional theory. Secondly, therc is
the cr-rrrent trend of externalism. I argtre that the latter causes trouble for the
former. If externalists are right, the "highest common factor" analysis of our
psychological states that underlies the reductionist project is mistaken. This
undermines the reductionist claim that our folk-psychological practice must either
reduce or must be eliminated.

The argument presented here offers a twist on Putnam's famous multiple
realizability argument. According to Putnam's famous argument, psychological
states can be realized in different ways. Differently realized psvchological states
clualify as the same kind of psychoiogical state, say be'ing in pain, because' the'y
share a common functional property.

But what if we reject this assumption? What if a particular kind of
psychological state, say the belief that it rains, is not characterized by a shared
functional feature, or any other common non-psychological aspect? What if what
counts as the same psychological state within our everydav practice makes up a
rather diverse cate.gory? If so, this shows that our need tcl understand one another
functions as a norm that allows us to group together divcrse states into the samc
caregory.

When we recognize the need to understand one another, we must admit that
inter-theoretic relations come in more varieties and are a more complicated affair
than some reductionists have assumed, to the extent that the reductionist
framework only applies to a limited amount of cases. One case that falls outside its
range is the relation between reductjonist theories about our psvchological states
and our everyday folk-psychological practice.