Quantum mechanics has
been used to explain just about everything that's so far
unexplainable. Consciousness doesn't escape that net (at least as cast
by non-scientists).
For example, perhaps the
nature of quantum phenomena can explain (or make sense of) good
old-fashioned mind-body dualism:
“… loosen
up our thinking and nudge us away from the simple billiard ball model
of causation… When this is combined with a certain influential
interpretation of quantum theory, dualism can start to seem, not
merely, possible, but positively commonsensical!” [2004]
Presumably this is
because in the “billiard-ball model of causation”, billiard balls
were required to be next to each other (or ‘contiguous’, as David
Hume put it) in order to affect one another. Theories of
quantum mechanics deny that this is necessary. There's talk of
“action at a distance”. However, it's not immediately clear what
this has to do with consciousness or dualism in the philosophy of
mind.
Is there an inference
here from
i) Action at a distance
tells us that objects needn't be next to each other to be causally
related.
to
ii) The non-physical
nature of mind doesn't need to be physical in order to causally
affect the physical.
Isn’t quantum
mechanical theory still about physical phenomena? (That is, no matter
how far apart they are and no matter how loose the definition of
‘physical’.) If the mind is simply non-physical (or made of
mind-substance), then it's not immediately obvious how quantum theory
helps dualism. It's not distance that's the issue here: it's the
fact that dualists believe that mind-substance can causally affect
body-substance.
We need more arguments to
accept the relevance of quantum theory for the mind-body debate. So
here’s one argument:
“If
minds were themselves parts of the material world, they would be,
like the camera in Tibble’s box, merely parts of the whole system,
hence themselves in a superposition of states.” [2004]
Again, it's not
immediately obvious how quantum theory provides some kind of defence
for dualism. Not even when we're given a parallel. The argument seems
to be that the mind is a superposition of states - as in the
Schrödinger’s cat thought-experiment. Would this automatically
make minds non-physical?
The other possibility is
that the minds are only parts of larger systems. Thus are we to
conclude that minds emerge from these larger total systems because
of, say, their very complexity?
E.J.
Lowe on the Self
One of the major problems
with Cartesian dualism is the clear fact that mind-substance is
viewed as being completely different to body-substance. The major
difference, according to Descartes, is that the mind is non-extended
and that the body is extended. What if a contemporary philosopher
accepted that account? E.J. Lowe does (partly) accept it. He says that it has
relevance to our notion of the self. John Heil expressed Lowe's
position thus:
“The
self, he holds, is perfectly simple. What could be the parts of a
self? You entertain different thoughts, your preferences evolve, and
memories come and go. But these are not parts of you in the way arms,
legs, hearts, and livers are parts of your body.” [2004]
The self, on this
picture, is like a Leibnizian monad. It too has no parts. It
follows that our thoughts, preferences and memories can’t be parts
of the self because the self is a perfectly simple unity. Not only
that: it's non-spatial or non-extended. How can something non-spatial
have parts... even in principle?
Thus if we have mental
items (of whatever sort), we can't see them as parts of our mind or
self. So what are they? How do they all belong together? How, indeed,
do they come and go? What do they belong to (if they belong to
anything)? How does the unity and continuity of the self come about
without physical (causal) connections?
The answer is that
mind-substance holds it all together. However, even with
mind-substance and non-extension we're still using spatial and
physical metaphors like “to bind” and “to contain”. A dualist
surely shouldn't be using such metaphors. Despite saying that, the
problem is that if he didn't do so, he'd effectively be denying
himself the possibility of saying anything. Metaphors and analogies
are all he has. And they get him into trouble.
Heil offers us a simple
thought experiment to help us determine whether or not dualism is in
fact true (or even if it makes sense). He talks in terms of a status
and the bronze out of which the statue is actually made. Heil writes:
“Now
imagine that the mind or self is related to the body in something
like the way the statue is related to the lump of bronze that is on
the scene when the statue is one the scene. Selves and bodies have
very different identity conditions, so there is no prospect of
identifying the self with the body. Moreover, the self is simple (or
so Lowe contends), altogether lacking in parts. Nevertheless the self
and the body (like the statue and the lump) might share certain
properties. If the body has a particular mass, so does the self; if
the body is in Gundagai, so is the self. The body and the self do not
share all their properties.” [2004]
We can intuitively say
that the lump of bronze is the statue. Or, less strongly, that
they're identical. Clearly we can't say the same about the body (or
brain) and the self. They do indeed have different properties. Though
does this mean that they aren't identical? Perhaps the self is X
under one description and the body is X under a different
description. This is pretty much what Donald Davidson believed in his
position of ‘anomalous monism’. That is, the mental and the
physical are indeed identical. However, the mental can't be
satisfactorily reduced to the physical; nor do they have the same
properties. That's because X is seen under two modes of
description (just as a table can be described qua table or qua
collection of moving molecules).
There's a hint of
Leibniz’s law here as well. That is, if the self has different
properties, and therefore things true of the body won't be true of
the self (as well as vice versa), then the self and the body can't in
fact be identical. However, that doesn't seem to work for the lump of
bronze and the statue. As Heil says, both share the same mass and
both exist in the same place at the same time. Despite that, the lump
of bronze must have existed before it was made into a statue. Since
that's the case, then the lump will have at least one property that
the statue doesn't have: being older than the statue.
If the self is indeed
simple, as Lowe contends, then it couldn't have the properties which
a body has. This, again, can be accounted for in terms of two modes
of description of the same thing. We have a mode of presentation of
the self that simply precludes us from giving it any properties.
Nevertheless, that's a result of a particular mode of presentation,
not of X. If the self is truly simple, how could we really
describe it at all, let alone say that it's the same as the body in
which it is supposed to exist?
Perhaps the self and body
can be identical; though not numerically identical. This doesn’t
help because it raises the prospect of identity-at-a-distance (as it
were). In any case, Leibniz would would have told that they can’t
be identical because they don't share all their properties. In fact
the self (whatever it is) shares no properties with the body or
brain. How could it? We've already been told that the self is simple
and non-extended. How could it share properties with something, the
body, which is complex and extended?
The old question therefore
arises:
If these radical
differences and distinctions between body and self are real, then how
can we account for the fact that they're connected in some - or in
many - ways?
This isn't only a
question of the improbability of causal connections between
mind-stuff and body-stuff: it's also about the improbability of any
substantive connections between substances which share no properties
whatsoever. We must conclude (if we are dualists) that the analogy
between self/body and lump/statue is far from being acceptable or
precise. The two examples simply aren't parallel in any way.
The most palatable
solution (in that it appears to be mid-way between dualism and
materialism) is the following juxtaposition of ‘substance monism’
and ‘property dualism’ (as advanced by Davidson, amongst others).
Heil writes:
“… 'property
dualism', the view that mental and physical properties, though quite
different, can be properties of one and the same substance.”
[2004]
The problem with this
position is that although it provides us with a middle way between
hard-core materialism (or eliminativism) and dualism (as well as what
seems like a satisfactory explanation), it in fact isn't really much
of an explanation at all. How can one and the same substance be the
ground or cause of two sets of completely unlike properties? How can
a single substance be responsible for these anomalies between
properties? It's an explanation; though not a solution to the
mind-body problem. Indeed, as has just been said, it's not really an
acceptable explanation at all!
Thus some philosophers
may accept it (along with supervenience) simply because they don't - or can't - accept any of
the alternatives.
References
Heil, John. (2004)
Philosophy
of Mind: A Guide an Anthology (pages 815-817)
Lowe. E.J. (1996)
Subjects
of Experience (see chapter 2)
