phenomenological position with what it is like tobesome person, creature, or
machine in a given situation. In the case of color perception, for example, it
is what it is like for you to experience a particular shade of redness or pale
blueness or whatever. This much seems perfectly clear. But if it is so clear, then
why not simply define consciousness with respect to such phenomenological
criteria?
As we said before, the difficulty is that first-person knowledge is available
only to the self. This raises a problem for scientific explanations of conscious-
ness because the scientific method requires its facts to be objective in the sense
of being available to any scientist who undertakes the same experiment. In all
matters except consciousness, this appears to wor kvery well. But conscious-
ness has the extremely peculiar and elusive property of being directly accessi-
ble only to the self, thus blocking the usual methods of scientific observation.
Rather than observing consciousness itself in others, the scientist is forced to
observe the correlates of consciousness, the ‘‘shadows of consciousness,’’ as it
were. Two sorts of shadows are possible to study: behavior and physiology.
Neither is consciousness itself, but both are (or seem likely to be) closely
related.
Behavioral Criteria The most obvious way to get an objective, scientific handle
on consciousness is to study behavior, as dictated by methodological behav-
iorism. Behavior is clearly objective and observable in the third-person sense.
But how is it related to consciousness? The lin kis the assumption that if some-
one or something behaves enough like I do, it must be conscious like I am.
Afterall,IbelieveIbehaveinthewaysIdobecauseofmyownconscious
experiences, and so (presumably) do others. I wince when I am in pain, eat
when I am hungry, and duc kwhen I perceive a baseball hurtling toward my
head. If I were comatose, I would not behave in any of these ways, even in the
same physical situations.
Behavioral criteria for consciousness are closely associated with what is
calledTuring’s test. This test was initially proposed by the brilliant mathemati-
cian Alan Turing (1950), inventor of the digital computer, to solve the problem
of how to determine whether a computing machine could be called ‘‘intelli-
gent.’’ Wishing to avoid purely philosophical debates, Turing imagined an ob-
jective behavioral procedure for deciding the issue by setting up animitation
game. A person is seated at a computer terminal that allows her to communicate
either with a real person or with a computer that has been programmed to
behave intelligently (i.e., like a person). This interrogator’s job is to decide
whether she is communicating with a person or the computer. The terminal is
used simply to keep the interrogator from using physical appearance as a factor
in the decision, since appearance presumably does not have any logical bearing
on intelligence.
The interrogator is allowed to as kanything she wants. For example, she
could as kthe subject to play a game of chess, engage in a conversation on cur-
rent events, or describe its favorite TV show. Nothing is out of bounds. She
could even as kwhether the subject is intelligent. A person would presumably
reply affirmatively, but then so would a properly programmed computer. If the
interrogator could not tell the difference between interacting with real people
16 Stephen E. Palmer