Reduction and Elimination in Philosophy and the Sciences

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There can be Causal without Ontological Reducibility of Consciousness? Troubles with Searle’s Account of Reduction — Tárik de Athayde Prata
“Notice that on this model (…) we could also draw
diagonal arrows which in this case would show that
the intention in action causes physiological changes
and that the neuron firings cause bodily movements.
Notice also that on such a model the mental phenomena
are no more epiphenomenal than the rise
in temperature of the firing of a spark
plug.”(SEARLE, 1983, p. 270) 2
I think that these “diagonal” causal relations correspond to
the identity of causal powers of conscious mental phenomena
and brain processes, the second aspect of
Searle’s conception of causal reduction. And if it is really
so, then this identity of causal powers is grounded on the
identity of the phenomena themselves. The connection of
(a) causal explanability and (b) identity of causal powers
with (c) the identity of the phenomena is a strong evidence
for the connection of causal and ontological reduction,
because ontological reduction yields the conclusion that
entities of certain types “consist in nothing but” (SEARLE,
1992, p. 113) entities of other types, what is for him a peculiar
form of identity relation that exists also by properties
(as liquidity, solidity and consciousness). Moreover, Searle
himself acknowledges that, in general, successful causal
reductions lead to ontological reductions: “where we have
a successful causal reduction, we simply redefine the expression
that denotes the reduced phenomena in such a
way that the phenomenon in question can now be identified
with their causes.” (SEARLE, 1992, p. 115) It seems to
me that the causal reduction makes such a possible redefinition
because the causal explicability and the identity
of causal powers allow an identity statement concerning
both phenomena (for example liquidity and molecular behavior).
But in Searle’s opinion there is an exception, there
is at least a phenomenon whose causal reduction does not
lead to an ontological reduction: consciousness.
III. The Argument for Ontological
Irreducibility
Ontological irreducibility leads to a situation that is in my
opinion very strange, namely that “Consciousness is entirely
causally explained by neuronal behavior but it is not
thereby shown to be nothing but neuronal behavior.”
(SEARLE, 2004, p. 119) We saw above that causal explicability
(and identity of causal powers) entails in Searle’s
view an identity relation between the phenomena in question,
but if it is not the case that consciousness is nothing
but neuronal behavior, then consciousness is something
else as neuronal behavior, so that it is not clear how consciousness
could be causally reducible. Appealing to
Thomas Nagel’s, Frank Jackson’s and Saul Kripke’s conceptions,
which (in his opinion) have articulated the same
argument in different ways (see SEARLE, 1992, p. 116-
117), Searle offers the following formulation:
“Suppose we tried to say the pain is really ‘nothing
but’ the patterns of neuron firings. Well, if we tried
such an ontological reduction, the essential features
of the pain would be left out. No description of the
third-person, objective, physiological facts would
convey the subjective, first-person character of the
2 In my presentation of Searle’s view of causal reducibility I refer to his remarks
about intentional states, while the subject of this paper is his account of
the reduction of consciousness. But it seems not problematic for me, because
Searle thinks consciousness and intentionality as connected, and makes
similar remarks about the causal efficacy of conscious sensations (see
SEARLE, 1995, p. 219). Moreover, he suggests that consciousness is identical
to brain behavior (although consciousness is caused by it – see SEARLE,
2002a, p. 9)
pain, simply because the first person features are
different from the third-person features.” (SEARLE,
1992, 117)
He says explicitly that subjective and objective features are
different, what is in my opinion incompatible with his conception
of causal reduction presented above (section II). A
redefinition of consciousness in terms of objective entities
(as brain processes) is impossible, and it seems to me to
undermine the possibility of a causal reduction in Searle’s
model. Such a causal reduction requires an ontological
reduction. But now we need to examine his argument for
the claim that ontological reduction has no deep consequences
and to evaluate if it can make causal reduction
compatible with ontological irreducibility.
IV. Is Ontological Irreducibility Harmless?
Searle refuses the general opinion that an ontological irreducibility
of consciousness is a challenge to our scientific
world view, and tries to prove that this irreducibility does
not force us to a property dualism. He believes that ontological
irreducibility is in this sense harmless because it is
a consequence of our interests about consciousness, and
not a consequence of the structure (or essence) of the
phenomenon itself (see SEARLE, 1992, p. 123). According
to him, an ontological reduction consists to carve off the
surface features of a phenomenon and to redefine it in
terms of the microlevel’s causes of these surface features.
We make this when our interest is to know about the microcauses.
The only difference between subjective states
of consciousness and objectives system features (as liquidity
or solidity) is that in the case of consciousness our
interest are the surface features, so that we cannot carve
off them.
But what draw my attention is that Searle compares
subjective with certain objective phenomena (as mud and
music, see SEARLE, 2004, p. 120) – because, when we
use the expressions “mud” and “music”, we are interested
on the surface features of these phenomena – and, moreover,
says that we could make the redefinition if we want.
These statements suggests (a) that consciousness is identical
to brain processes and (b) that we are not interested
in this identity when we use the expressions “consciousness”,
“pain”, etc. – as we are not interested in the identity
of music and air movements when we speak, for example,
about Beethoven’s ninth symphony. But these two claims
seem problematic to me. Searle himself says that subjective
and objective features are different – what becomes
clear when we note that the description of molecular behavior
can convey the surface features of mud, while the
description of brain processes cannot convey the surface
features of consciousness – and the fact that we are not
interested in microcauses when we speak about surface
features is trivial and cannot explain ontological irreducibility.
If objective descriptions never would convey the
subjective character of conscious states, because they are
different, then ontological irreducibility does not follows of
our pragmatics interests in the surface features. 3
3 A further strategy to defend Searle’s view would be to say that he takes
consciousness not for identical but for supervenient to brain processes. But his
position about supervenience is ambiguous. On one hand he says: “It is certainly
true that consciousness is supervenient on the brain” (SEARLE, 2004, p.
148). On the other hand he finds this concept not helpful and thinks that his
own theory of cross-level causation (that implies identity) is more interesting:
“the concept of supervenience adds nothing to the concepts the we already
have, such concepts as causation, including bottom-up causation, higher and
lower levels of description, and higher order features being realized in the
system composed of the lower level elements.” (SEARLE, 2004, p. 149). The