Reduction and Elimination in Philosophy and the Sciences

There can be Causal without Ontological Reducibility of Consciousness?
Troubles with Searle’s Account of Reduction
Tárik de Athayde Prata, Fortaleza, Brazil
I. Introduction
In his writings about the philosophy of mind John R. Searle
often deals with the question of reduction, because the
main question in this field can be defined in these terms:
do the mental phenomena have a special mode of existence
or are they reducible to physical phenomena? (see
SEARLE, 1992, p. 2). But it is not clear whether his account
of reduction is really coherent. Searle distinguishes
different types of reduction (see SEARLE, 1992, p. 113-
114), but when he speaks about consciousness, he makes
incompatible claims. The two types that are relevant here
are causal and ontological reduction. The main problem is
that he thinks of consciousness as a special case, in which
these two types of reduction are not equivalent: consciousness
can be causally but not ontologically reduced,
and that seems to commit him with the contradictory
claims that consciousness is and is not identical to brain
behavior. In the present paper, Searle’s conception of
causal reduction and its relations with ontological reduction
will be examined (section II), as well as his argument for
the ontological irreducibility of consciousness (section III),
which seems to be in contradiction with this conception of
causal reduction. After that, Searle’s arguments for the
thesis that ontological irreducibility does not force us to
dualism are going to be discussed (section IV). My conclusion
is that this last argument fails, so that ontological irreducibility
entails a kind of dualism, and Searle states and
denies (in contradictory way) the identity of consciousness
and brain processes.
II. Causal and Ontological Reduction
Searle defines the causal reducibility of consciousness as
follows:
“Consciousness is causally reducible to brain processes,
because all features of consciousness are
accounted for causally by neurobiological processes
going on in the brain, and consciousness has no
causal powers of its own in addition to the causal
powers of the underlying neurobiology.” (SEARLE,
2002b, p. 60, my emphasis)
A causal reduction of consciousness consists of the causal
explanability of its surface features by brain processes at
the microlevel and the identity of causal powers of both.
These two aspects are closely related to an identity thesis
concerning consciousness and brain behavior.
Firstly, causal explanability entails that the surface
features of the phenomenon are caused by the behavior of
the system’s microstructure in which the phenomenon is
realized in. But this causation does not mean that we have
to do with two different things. In Intentionality the author
mentions:
“there can be causal relations between phenomena
at different levels in the very same underlying stuff
(…) to generalize at this point, we might say that
two phenomena can be related by both causation
and realization provided that they are so at different
levels of description.” (SEARLE, 1983, p. 266, my
emphasis)
Searle’s conception of the causation of surface features by
the system’s microstructure behavior does not concern an
event which causes another, but a sufficient condition
without temporal connotations (see SCHRÖDER, 1992, p.
100).
Secondly, the identity of causal powers is presented
by Searle as a consequence of an identity relation between
both phenomena. In one of his first writings on the
philosophy of mind Searle defended the causal efficacy of
mental phenomena and thought the description of its
causal powers as possible at different levels: “Mental
states are no more epiphenomenal than the elasticity and
puncture resistance of an inflated tire are, and interactions
can be described both at the higher and lower levels, just
as in the analogous case of the tire.” (SEARLE, 1980, p.
455, my emphasis)
Furthermore, it is clear that the identity of causal
powers follows from the fact that both phenomena are the
same thing described at different levels. These two points
(the connection of causal explanability and of the identity
of causal powers with the identity of both phenomena)
become more understandable if we consider Searle’s
scheme for the representation of the causal functioning of
mental states. In Intentionality he draws the following
picture:
Searle asserts explicitly that “the phenomena at t1 and t2
respectively are the same phenomena described at different
levels of description” (SEARLE, 1983, p. 269, my emphasis),
what entails that the “cross level” causation between
neuron firings and the intention in action is causation
with identity, and the simultaneous relation of realization
between them determines this identity. 1 This is, the
causal explanability of the features of a conscious mental
phenomenon is made possible by causal relations without
time gap, by causal relations between different levels of
the same system. And once that the phenomena at t1 and
t2 are identical, he says that there are also “diagonal”
causal relations between the phenomena at t1 and t2:
1 Explaining the realization relation in the case of liquidity Searle writes: “the
liquidity of a bucket of water is not some extra juice secreted by the H2O
molecules. When we describe the stuff as liquid we are just describing those
very molecules at a higher level of description than that of the individual molecule.”
(SEARLE, 1983, p. 266, my emphasis)
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