Reduction and Elimination in Philosophy and the Sciences

A Division in Mind. The Misconceived Distinction between
Psychological and Phenomenal Properties
Matthias Stefan, Innsbruck, Austria
1. Chalmers’ division of mind
According to David Chalmers (Chalmers 1996, 11-13)
there are psychological and phenomenal concepts of the
mind. The phenomenal concept of mind expresses that
there is something it is like to be in a certain mental state.
The psychological concept of mind is “the concept of mind
as the causal or explanatory basis for behaviour. A state is
mental in this sense if it plays the right sort of causal role in
the production of behaviour [...]” (Chalmers 1996, 11). In
other words, our mental life can be divided into an aspect
of the way it feels like to be in that state and into an aspect
of the role it plays for our behaviour. So far, this distinction
is conceptual (Chalmers 1996, 12).
Soon, however, this conceptual distinction turns into
an ontological one about phenomenal and psychological
properties (e.g. Chalmers 1996, 16, 22-24). Chalmers sees
this ontological distinction as exhaustive: Every mental
property is either a psychological or a phenomenal
property, though most mental concepts encompass both
components (Chalmers 1996, 16-17). Take, for instance,
pain: Pain can be analysed as phenomenal and
psychological property: The phenomenal one describes
the way it feels like to be in pain, the pain-experience so to
say. The psychological property can be identified with the
pain-behaviour and the accompanied beliefs, desires and
more. Though according to Chalmers there is a real
distinction between these kinds of properties, there is also
a co-occurrence of them (Chalmers 1996, 22).
Nevertheless, these two properties must be distinguished,
since there are two explananda. Phenomenal properties
cannot be defined in functional terms and psychological
properties are not phenomenal. Therefore, we can imagine
situations where a phenomenal property is instantiated
without a psychological property – and vice versa
(Chalmers 1996, 23).
A crucial result of the ontological division between
psychological and phenomenal properties is an
epistemological division in philosophy of mind: “The
division of mental properties into phenomenal and
psychological properties has the effect of dividing the
mind-body problem into two: an easy part and a hard part.”
(Chalmers 1996, 24) The easy problem concerns
psychological properties. As they are definable in
functional terms, they do not really pose a hard problem for
cognitive science. Science can explain the psychological
property with the underlying physical mechanism that plays
the pertinent causal role (ibid.). So the explanation of
psychological properties “is a question for the sciences of
physical systems. One simply needs to tell a story about
the organization of the physical system that allows it to
react to environmental stimulations and produce behaviour
in the appropriate sorts of ways.” (ibid.) Of course, the
easy problem is only relatively easy, as there remain
considerable difficulties. However, we know in principle
how to solve it, how to explain believes, desires, wishes,
memory, etc. This is not true in case of the hard problem
concerning phenomenal properties. We don’t know why
and how psychological functions are accompanied with
phenomenal states (Chalmers 1996, 25). The explanatory
gap Levine famously stated some time ago is as wide
open as ever (Levine 1983). We have no idea why it is
something it is like to be in a mental state. Chalmers
therefore writes: “As we saw above, we now have a pretty
good idea of how a physical system can have
psychological properties: the psychological mind-body
problem has been dissolved. What remains is the question
of why and how these psychological properties are
accompanied by phenomenal properties […]” (Chalmers
1996, 25).
2. Kim’s approximation to physicalism
Jaegwon Kim adopts Chalmers distinction for reaching an
interpretation of reality near enough to physicalism (Kim
2005). Kim declares himself a physicalist: The world we
live in is physical and so are the human person and her
mind. Without going into details why the mental realm has
to be physical, I concentrate on Kim's view how it is.
According to Kim mental states are identical with
physical states. The relation of reduction that
demonstrates this identity relation is functional reduction:
As the term says, the first step in functional reduction is to
define the reducible property functionally. Kim brings the
well-known example of a gene that is defined as “a
mechanism that encodes and transmits genetic
information” (Kim 2005, 101). Once we have found a
definition in terms of the causal role a property plays, we
can look for the “causal realizer”, that is the property in the
reduction base that plays the demanded functional role. To
continue the example given above, it turns out that DNA
performs the mechanism that defines the concept of a
gene. In the last step of functional reduction, a theory has
to be given that explains “how the realizers of the property
being reduced manage to perform the causal task” (ibid.).
In case of the gene example, molecular biology provides
the explanation demanded.
In asking whether the mental realm is reducible to
the physical, Kim refers to Chalmers’ distinction between
psychological and phenomenal properties (Kim 2005,
162). As shown, for reducing something it first needs to be
defined in functional terms. Therefore the question
whether mental properties can be reduced comes up to
the question which properties can be functionalized (Kim
2005, 165). Kim adopts Chalmers’ proposal that
psychological properties, called cognitive properties by
Kim, can be explained by cognitive science, which is the
same for Kim as to reduce them (see Kim 2005, 108-112
and 162). Thus, they can be identified with causal realizers
in the physical basis (Kim 2005, 165). Even though we
might not find full causal definitions of psychological
properties, it is safe to say that they are identical with
physical states (Kim 2005, 167).
Furthermore, Kim and Chalmers also agree on the
irreducibility of phenomenal properties, or qualia (the
classic term Kim uses). Phenomenal properties are not
definable by their causal role and therefore cannot be
functionally reduced: “So qualia are not functionalizable,
and hence physically irreducible. Qualia, therefore, are the
‘mental residue’ that cannot be accommodated within the
physical domain.” (Kim 2005, 170) Kim takes stock: Almost
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