The Mary Chronicles
109
detail in the present book. However, there is an animated exchange of views
among philosophers and scientists—on both sides of the controversy—which
has come to be known as the Mary Chronicles. Though most of the debate is
contained in papers found in scholarly journals, a few representative ones are
collected in a recent book which makes entertaining reading and sets out the
principal viewpoints. 2 The question debated in these papers is whether the
sensations that a person experiences—in this case the sensation of colors—can
be reduced to electrical activity in the brain, or whether it is something that is
not physical.
The underlying premise of the Mary Chronicles is that a scientist named
Mary has been imprisoned all her life in a dungeon in which everything is
a uniform grey. She has a computer with a black-and-white screen, and has
learned absolutely every material fact about color vision. One day she is rescued
by a philosopher-prince 3 , and as she goes into the garden she sees color for the
first time. Frank Jackson, the author of this tale, asks whether at the moment
she steps into the garden, Mary learns something she did not know before: If
she does, it cannot be a material fact, for she already knew all the material facts
about color vision. So her experience of color is not something material.
Jackson proposes this mind-experiment as proof that not all mental things
are physical. The subjective experience of color, for example, is not. Thus,
although Mary knew all the facts of the color experience, she did not know
the feel of it. The feel is something new which Mary could not have known
before, because it is not something physical.
Materialist philosophers don’t agree with that reasoning: Famously, David
Lewis asserts that what Mary has discovered in the garden is a new ability:
She now has the skill needed to recognize colored things when useful, for
example in daily tasks. In Lewis’s view, such abilities are mundane pragmatic
skills necessary for survival, and nothing more. It’s something we are able to
do, not something we know.
Others argue that since Mary already knew all the facts of the color experience, she couldn’t have learned anything new. Rather, in the garden she
encountered something she already had knowledge of, but it was now presented to her in a different form. The point of this objection, like the previous
one, is to argue that if Mary already knows all the material facts about the
color experience, then she learns nothing new because there is nothing more
to subjective experience than physical fact.
On the other side of the fence are the philosophers who aim to discredit
the physicalist viewpoint. One of their stratagems is the Zombie argument.
In philosophy, Zombies are imaginary quasi-humans that resemble humans
in every anatomical and physiological particular – even their brain structure
109
detail in the present book. However, there is an animated exchange of views
among philosophers and scientists—on both sides of the controversy—which
has come to be known as the Mary Chronicles. Though most of the debate is
contained in papers found in scholarly journals, a few representative ones are
collected in a recent book which makes entertaining reading and sets out the
principal viewpoints. 2 The question debated in these papers is whether the
sensations that a person experiences—in this case the sensation of colors—can
be reduced to electrical activity in the brain, or whether it is something that is
not physical.
The underlying premise of the Mary Chronicles is that a scientist named
Mary has been imprisoned all her life in a dungeon in which everything is
a uniform grey. She has a computer with a black-and-white screen, and has
learned absolutely every material fact about color vision. One day she is rescued
by a philosopher-prince 3 , and as she goes into the garden she sees color for the
first time. Frank Jackson, the author of this tale, asks whether at the moment
she steps into the garden, Mary learns something she did not know before: If
she does, it cannot be a material fact, for she already knew all the material facts
about color vision. So her experience of color is not something material.
Jackson proposes this mind-experiment as proof that not all mental things
are physical. The subjective experience of color, for example, is not. Thus,
although Mary knew all the facts of the color experience, she did not know
the feel of it. The feel is something new which Mary could not have known
before, because it is not something physical.
Materialist philosophers don’t agree with that reasoning: Famously, David
Lewis asserts that what Mary has discovered in the garden is a new ability:
She now has the skill needed to recognize colored things when useful, for
example in daily tasks. In Lewis’s view, such abilities are mundane pragmatic
skills necessary for survival, and nothing more. It’s something we are able to
do, not something we know.
Others argue that since Mary already knew all the facts of the color experience, she couldn’t have learned anything new. Rather, in the garden she
encountered something she already had knowledge of, but it was now presented to her in a different form. The point of this objection, like the previous
one, is to argue that if Mary already knows all the material facts about the
color experience, then she learns nothing new because there is nothing more
to subjective experience than physical fact.
On the other side of the fence are the philosophers who aim to discredit
the physicalist viewpoint. One of their stratagems is the Zombie argument.
In philosophy, Zombies are imaginary quasi-humans that resemble humans
in every anatomical and physiological particular – even their brain structure