Reply to a Critic of Chapter Seven (Pains)
Beyond Experience -
Metaphysical Theories and
Author: Norman Swartz
Publisher: Toronto University Press
ISBN: 0-8020-2783-0 (cloth)
ISBN: 0-8020-6832-4 (paper)
Chapter Seven, in which I argue for the conceptual possibility of
pains existing outside of one's body, indeed even being shared by two
or more persons, has proven exceedingly troublesome for some readers.
One reviewer of Beyond Experience singled out this chapter
for special comment:
... a (rare) place where Swartz's discussion loses credibility is
his alleged possible world (see pp. 118 ff.) where we would call
something a pain that was literally outside of our body. While it
is fun and often enlightening to envisage possible worlds, surely
the experience of pain, the having a pain, is always in one's
brain. In the actual world, pains are private because they are
brain states. If Swartz is trying to show only that they might
not have been brain states, he would be right. But so long as
pains are experiences and not objects of perception, they cannot
sensibly be said to be shared (unless by Siamese twins sharing a
brain) or public. Pains could not literally be out of the body
and at the same time experiences. If we imagine a world where
pains are analogous to colours, of course, this is not
necessarily true. Jack Ornstein, Canadian Philosophical
Review, vol. XII (2)-(5) (April 1992–Oct. 1992), pp. 355.
By way of defense, I would reply that if pains can be likened (there
are of course differences) to tactile sensations, then there is not only
a conceptual possibility of having pain sensations outside of
one's body, there has been, more recently, actual laboratory evidence
bearing on the question. I reproduce below an article reporting an
experiment that demonstrates out-of-body tactile sensations.
This Here Hand Is My Hand, I Think
in a recent psychological study will probably
never look at mannequins – or their own bodies – in quite
the same way again. Before the study, they knew their arms
belonged to them and synthetic ones didn't, simply because seeing
is believing. Now they're not so sure.
Researchers at Carnegie Mellon University in Pittsburgh asked
subjects to keep their eyes on a rubber arm that was sitting on a
table in front of them, With the subject's left arm hidden from
view by a screen, the researchers simultaneously stroked both the
rubber hand and the subject's hand with a paintbrush. Even though
they knew their own hand was being stroked behind the screen,
nearly all the subjects experienced the same bizarre sensation:
they felt the fake hand was actually their own.
According to Matthew Botvinick, the Ph.D. psychology student who
coauthored the study with advisor Jonathan Cohen, awareness of
self seems to depend on intricate conversations between the brain
and a range of sensory inputs that it constantly receives. If
those conversations become garbled by contradictory messages, the
brain is even willing to stretch the bounds of where the body
ends and the outside world begins in order to draw a coherent
"It's like ventriloquism," says Botvinick, who was so spooked by
the illusion when he tested it on himself that he let out a yelp
and threw the fake hand across the room. "In the experiment,
when something touches the fake hand, you feel it, so the rubber
hand appears to be an object with which you sense. And when there
is an object of that kind, it's usually part of you. That seems
to be one basis of self-identification."
To confirm that the subjects were experiencing a true shift in
their perception of themselves, researchers asked them to run
their right index finger along the underside of the table until
it was directly underneath their left one. Those who had
experienced the rubber-hand illusion invariably missed their real
finger altogether and pointed more closely to the fake hand.
"When you look at your hand, it doesn't feel as if your brain
might be going through all kinds of complicated computations to
arrive at the conclusion that this thing is yours," says
Botvinick. "You just know it's your hand."
Jennifer Van Ezra, in the column "Nexus" in
Equinox, no. 99 (July 1998), p. 14.