Reduction and Elimination in Philosophy and the Sciences

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Four Anti-reductionist Dogmas in the Light of Biophysical Micro-reduction of Mind & Body — Theo A. F. Kuipers
all. MB-laws are laws that relate M- and B-properties
and/or MB-properties. Note that in my approach, MB-laws
are as a rule or even always correlations, MB-correlations
for short. Correlations may be causal or ontological
correlations, in the latter case they are incomplete, e.g., of
a part-whole nature, such that they cannot be considered
as ontological identities. The question of whether there are
MB-identities, besides MB-correlations, is irrelevant in my
micro-reductionist approach, for both concern relations on
the macro-level.
In this terminology the really interesting question is
whether at least some M- or MB-concepts or even some
M- or MB-laws can be reduced, straightforwardly or
approximately, to biophysical micro-concepts and -
theories. As long as reduction of, say, an M-concept is not
successful, it may well be that we can find one or more
MB-correlations and ‘ontological’ correlations, that is,
correlations between the M-concept and micro-concepts.
For instance, neuro-imaging techniques may show that
certain areas and processes on, relatively speaking, the
macro-level of the brain are specifically related to a certain
M-concept. Such MB-correlations may well be a crucial
step for an ultimate reduction of the M-concept. Moreover,
electrophysiological, neuro-anatomical, and neurochemical
experiments, for instance, may show that certain types of
neurons or neurotransmitters are involved in M. Such
ontological correlations may be part of an ultimate
reduction. Similarly, as long as the reduction of, say, an Mlaw
is not successful, it may be that we can find a microtheory
that enables the explanation, together with suitable
concept correlations, of the M-law.
Further Analysis
In the following analysis, I will essentially apply the analysis
presented in Chapters 3 and 5 of SiS to individuals,
humans and other animals. In order to simplify the presentation
I will restrict the attention to MB-concepts and MBlaws,
relating MB-concepts, since the story is essentially
the same for pure M-concepts and M-laws, if any exist, for
B-concepts and B-laws, and for MB-laws relating pure M-
and B-concepts. Let us concentrate for a while on the
macro-concepts and let us assume a finite number of families
of MB-types, i.e., sets of mutually exclusive and together
exhaustive, monadic MB-predicates, each family
giving rise to an MB-representation of an individual at each
moment. The MB-predicates at the start are supposed to
be types in the sense that their application is stable and
strongly intersubjective and/or because they are lawfully
correlated with other types.
Let us now conceive individuals, and their
environment as far as relevant, as (organized) aggregates,
to be described in terms derived from ‘base-terms’. It is
important to distinguish between the genuine baseconcepts
for the constituents, e.g., molecules or cells, etc.,
and their mutual relations, and the representation of
aggregates of these constituents, e.g., substances and
tissues. The latter may be done by construing set-theoretic
‘micro-structures’ in terms of the (biophysical) baseconcepts.
The micro-structures will be indicated as CSstructures,
because the micro- or base-entities are
supposed to be Cells, in particular neurons, and (micropieces
or -amounts of) Substances. The latter are included
in order to be able to take non-biological micro-entities in
the brain, the body and the environment into account.
Each CS-structure represents a conceptual possibility of a
state of an aggregate.
A CS-structure is a token of as many (disjunctions
of) CS-types as can be meaningfully defined as sets of
structures, using aggregate concepts, i.e., concepts
characterizing a certain aspect of the structure, e.g., the
internal and external temperature, the ratio of activated
neurons in a certain layer or region of neurons involved,
etc. Moreover, the idea is of course that many different,
though probably in some way or other related CSstructures,
may realize (approximately) the same MBconcept,
e.g., the same memory or pain. This set of
structures is called the realization-class of that MBconcept.
If a structure belongs to such a class, it is also
said to be a token of the realization-type of that concept.
Let us now formulate some possible reduction
results concerning some MB-families that would be
considered as successes. For this purpose we have to
assume at least the Token-Identity Hypothesis; i.e., every
state of an individual can be represented by an MB-type of
each MB-family as well as by a CS-structure. Additionally
the Realization Hypothesis has to be adopted; i.e., every
CS-structure uniquely determines, as a matter of
ontological fact, an MB-type for each MB-family. Note that
the Realization Hypothesis implies that each structure can
be represented as a member of the realization-class of
precisely one MB-property of each family. In other words,
that structure is a token of the realization-types of those
MB-properties.
It is possible to distinguish (SiS, Chaper 5) three
degrees of concept (micro-)reduction. A result of the first
degree is the quasi-type-type reduction of some MB-type,
say an MB-state. This result only presupposes that it is
possible to characterize a set of CS-structures as the
realization-class of that MB-state. Assuming that the CSstructure
representation of a state can be experimentally
established, the reduction enables the prediction of the
MB-state on the basis of the CS-structure representation
(quasi-reduction) and, conversely, being in an MB-state
predicts that the CS-structure representation belongs to
the realization-class of that MB-state. Of course, given that
the realization-class is not exclusively defined in CS-terms,
for it is by definition ‘MB-induced’, both kinds of prediction
concern CS-structure representations that are (very)
similar to those that were used to characterize the
realization-class.
As soon as a realization-class can also be
characterized independently in CS-terms, in the form of a
disjunction of CS-(micro-)types, exemplifying a multiple
version of the Type-Type Identity Hypothesis, see below,
we get the possibility of a one-many or multiple type-type
reduction of an MB-state: the second degree of reduction.
A second degree reduction enables the deduction of the
realization-type and hence the MB-state when one knows
that the CS-structure of the state belongs to the disjunction
of the corresponding CS-(micro-)types. The special case
that the realization-type corresponds to just one CS-type,
exemplifying the singular version of the Type-Type Identity
Hypothesis, is a third degree result: the one-one or
singular type-type reduction of an MB-state. According to
the singular Type-Type Identity Hypothesis, belonging to a
certain macro-type and to a certain micro-type amounts to
an ‘ontological equivalence’.
The foregoing classification immediately leads to
three degrees of (micro-)reduction of laws. First, if two MBtypes
are lawfully connected and both can be quasireduced,
it may be possible that the law can be reduced by
a theory in a weaker sense than occurs in reduction by
identification according to a general model (SiS, Chapter
3), viz., that, starting from one or more specific theory