It seems that one of the implicit assumptions in the all-universe model
is that consciousness is real and that we can determine whether whether
consciousness would exist in a particular universe. This allows us to
apply the anthropic principle and argue that the most probable universes
which allow consciousness to exist are the ones we should observe.
An essay at the Edge site by Stanislas Dehaene challenges the
meaningfulness of "consciousness" as a descriptive term, comparing it to
"life" as something which turns out not to be well defined. How would
this affect the use of the anthropic principle in attempting to draw
predictions from the AUH?
The essay, available at
http://www.edge.org/documents/questions/q2001.2.html#dehaene,
follows below.
Hal
===
"The definition of life and consciousness?"
Some scientific questions cannot be resolved, but rather are dissolved,
and vanish once we begin to better understand their terms.
This is often the case for "definitional questions". For instance,
what is the definition of life? Can we trace a sharp boundary between
what is living and what is not living? Is a virus living? Is the
entire earth a living organism? It seems that our brain predisposes
us to ask questions that require a yes or no answer. Moreover,
as scientists, we'd like to keep our mental categories straight
and, therefore, we would like to have neat and tidy definitions of
the terms we use. However, especially in the biological sciences,
the objects of reality do not conform nicely to our categorical
expectations. As we delve into research, we begin to realize that
what we naively conceived of as a essential category is, in fact, a
cluster of loosely bound properties that each need to be considered
in turn (in the case of life: metabolism, reproduction, autonomy,
homeostasy, etc..). Thus, what was initially considered as a simple
question, requiring a straightforward answer, becomes a complex issue
or even a whole domain of research. We begin to realize that there
is no single answer, but many different answers depending on how one
frames the terms of the question. And eventually, the question is
simply dropped. It is not longer relevant.
I strongly suspect that one of today's hottest scientific questions,
the definition of consciousness, is of this kind. Some scientists seem
to believe that what we call consciousness is an essence of reality,
a single coherent phenomenon that can be reduced to a single level
such as a quantum property of microtubules. Another possibility,
however, that consciousness is a cluster of properties that, most
of the time, cohere together in awake adult humans. A minimal list
probably includes the ability to attend to sensory inputs or internal
thoughts, to make them available broadly to multiple cerebral systems,
to store them in working memory and in episodic memory, to manipulate
them mentally, to act intentionally based on them, and in particular to
report them verbally. As we explore the issue empirically, we begin
to find many situations (such as visual masking or specific brain
lesions) in which those properties break down. The neat question
"what is consciousness" dissolves into a myriad of more precise and
more fruitful research avenues.
Any biological theory of consciousness, which assumes that
consciousness has evolved, implies that "having consciousness" is not
an all-or-none property. The biological substrates of consciousness
in human adults are probably also present, but only in partial form,
in other species, in young children or brain-lesioned patients. It is
therefore a partially arbitrary question whether we want to extend
the use of the term "consciousness" to them. For instance, several
mammals, and even very young human children, show intentional behavior,
partially reportable mental states, some working memory ability - but
perhaps no theory of mind, and more "encapsulated" mental processes
that cannot be reported verbally or even non-verbally. Do they have
consciousness, then? My bet is that once a detailed cognitive and
neural theory of the various aspects of consciousness is available,
the vacuity of this question will become obvious.
STANISLAS DEHAENE, researcher at the Institut National de la Santé,
studies cognitive neuropsychology of language and number processing
in the human brain; author of The Number Sense: How Mathematical
Knowledge Is Embedded In Our Brains.
Received on Mon Jan 15 2001 - 11:34:37 PST