|
"Every
science confesses that the subtlety of nature flies beyond it, and that
its formulas are but approximations."
–William James,
The
Varieties of Religious Experience
This
page contains a provisional statement of my epistemological viewpoint,
which may or may not be
of interest to the philosophically inclined. I wrote it in response to
an interesting article defending functionalism and the use of
psychological constructs, which is available on the web:
Practically
speaking, my epistemology suggests the utility of psychological
research and theory that is guided by psychological constructs but
constrained by neuroscience, with the understanding that the two
domains describe the same phenomena at different levels of resolution
or abstraction.
The following requires
some understanding of the terms "role" and "realizer." "Role" refers to
something's function, what is does (e.g., money). "Realizer"
refers to the specific entity that plays a given role (e.g., a dollar, a
peso). Basic physical entities (e.g., subatomic particles), are often
considered to be the real or ultimate realizers of any role, but
I
argue that it's not so simple:
Deep Functionalism: A Response to Ross and Spurrett
A deeper functionalism might assert that
because all of our explanations are partial and imperfect (which I
think we can accept as a pragmatic necessity, even if the question of
whether this must be so in principle remains open), even the
explanations of physics are essentially functionalist. This is not
incompatible with reductionism, in one sense: forms of less abstract,
more general, explanation (e.g., physics) could still be used to explain
the same phenomena that are explained in more abstract, more
specialized, ways (e.g., psychology), though usually with a loss of
efficiency so massive as to render them pragmatically useless (imagine
having to specify the interaction of every particle directly involved
in any act of perception, in both the organism and its environment ).
In another sense, however, it illegitimates the chauvanism of
reductionism, which claims hegemony for more basic (typically physical)
causal
explanations. From my perspective, it makes as much sense to
talk about a “role” causing an effect as it does to talk
about a
“realizer” causing an effect because there can be no hard
and fast line
between roles and realizers. All of our explanatory constructs (even
those of physics) are ultimately roles rather than realizers because of
their partialness and their imperfection. The actual complexity of the
world (i.e., that which exists ontologically) is always infinite
relative to our capacity to model it (again, perhaps in principle, but
at least from a pragmatic perspective). Unless we naively thought that
our model of a photon captured every possible thing there is to know
about the phenomena we describe with this model, we could not avoid the
question of what it is that realizes the role of photon (string theory
anyone?). Further, an answer to this question would not settle the
matter, but would simply extend the infinite regress one step further.
All of this entails that reductionism is a
concept only applicable in practice epistemologically – that is,
only
applicable to our explanations and understandings. The question of
ontological reductionism is another one entirely, and one that is
perhaps ultimately meaningless. What could ontological reduction mean?
Given that all of our explanations are partial and imperfect, none of
them picks out any portion of the universe in all its detail. This does
not necessarily mean, however, that we have no access to some Kantian
thing-in-itself; rather it means that whatever access we may have must
always be limited. Nonetheless, this limitation has important
consequences. If we cannot grant the ontological sanctity of basic
physical constructs, do we have grounds for saying that particles x, y,
and z are what “really” exist, and all other
phenomena,
ontologically
speaking, are merely the interaction of these particles? It seems to me
that we do not. Rather, we have to grant equal potential ontological
status to descriptions of phenomena at any level. Any of them may be
picking out genuine patterns of regularity in the structure of the
universe.
Applying the idea of epistemological reduction
(perhaps “epistemological unification” would be a less
objectionable
phrase) – which refers to the harmony possible, in principle,
between
different levels of explanation – to the relation between
psychology and
neuroscience, we can assume that the mental description M is a
description of the same
phenomenon as the physical description P, but
at a different level. The brain state, P, doesn’t cause you to think
the thoughts, M; the brain
state is you thinking the
thoughts (assuming M and P are coextensive in time).
Inasmuch as there is some hierarchy
of levels of explanation, in which things seem intuitively to become
more realizer-like as we move down through biology and chemistry toward
physics, this hierarchy does not indicate ontological primacy, but
rather spatio-temporal specificity. Brain states may change without
changing mental states, but mental states may not change without
changing brain states (this state of affairs is often called
“supervenience”; the mental supervenes on the physical).
Does this indicate that the brain states are
more real? No, just that they describe more specifically localized
patterns. Again, remember that, in practice, neither mental nor
physical description will capture the phenomenon in all its detail.
Causal assertions are thus equally valid at either level, but what
about across levels? M1
may be said to cause M2
and P1 may be said
to
cause P2, but can M1 cause P2 or P1 cause M2? Whether we allow the
latter kind of statement appears to be merely an aesthetic matter. It
may be less tidy to describe causes across levels, but if
epistemological reductionism holds, nothing makes such a crossing
inherently unintelligible. An example: if I am anxious, my being
anxious is equivalent to a particular brain state (more
accurately, a
set of brain processes).
Those brain processes do not cause my anxiety;
rather, they are my anxiety.
Being anxious may then cause me to think
less clearly. My muddled thinking is another particular set of brain
processes. This chain of events can be validly described in several
other ways: 1. The first set of brain processes caused the second. 2.
Being anxious caused the second set of brain processes. 3. The first
set of
brain processes caused me to think less clearly. This illustrates my
contention that a description of patterns at any level, or across any
levels, may validly discuss causes. Further a description of causes
across levels does not necessarily deny the closedness of physics,
unless we assume that a mental description is somehow fundamentally
different from a physical description. Rather, let me suggest that all
descriptions are physical descriptions (though “physical”
could perhaps
fruitfully be replaced with some more general term), in the sense that
all descriptions attempt to describe patterns, of equal ontological
status, in the same universe.
C. G. DeYoung, 2003
Post Script: The example in the previous paragraph raises an important
issue, which I want to acknowledge without going into too much detail.
One might argue that a crucial difference between anxiety and its
associated brain processes is that anxiety can be subjectively
experienced while the brain processes can only be detected by various
instruments. I would agree, but I don't think that this difference
renders these two things fundamentally distinct, ontologically --
rather it indicates
two different methods for learning about the same events.
[Back to Homepage ... Back to Top]
|
|