computationally fast and massive their capabilities are, no matter
how intelligent and creative, no matter what capacity they have to
learn or to apply what they have learned to improve their problem-
solving and creative capacities, they are still not thought to have men-
tal experience, conscious awareness, sentience—except in some sci-
ence fiction scenarios.
We feel there to be something special about life, nervous systems,
brains—and rightly so. After all, life on Earth has been evolving for
billions of years, and nervous systems and brains have been under-
going evolutionary tuning for hundreds of millions of years. It surely
must be the case that living systems have structures and capacities
that are far, far more sophisticated, nuanced, and complex than what
a few decades of scientific probing, explanation, and speculation have
given us access to. As Max Delbriick commented in a lecture given in
1949: “Any living cell carries with it the experiences of a billion years
of experimentation by its ancestors. You cannot expect to explain so
wise an old bird in a few simple words.”
So, what does it take to manifest mind? What conditions are needed
for mental experience, and for consciousness of that experience?
Clearly our brains and bodies are involved in determining the proper-
ties of our minds. Changes in the brain and body from lesions or the
ingestion of psychoactive drugs are related in specific ways to changes
in mental function. Brain activity as measured by electroencephalog-
raphy, positron emission tomography, and functional magnetic reso-
nance imaging correlates with aspects of mental experience.
But exactly how mind is related to body and brain physiology
remains a deep mystery. Thus, we return to the question that began
this book—this short odyssey from mind through brain and back
again: how is mind related to brain and body? How indeed is mind, is