My latest Wall Street Journal article is on Nick
Humphrey's theory of consciousness, as set out in his fine new
book Soul Dust

In 'The Theory of Moral Sentiments," published in 1759, Adam
Smith boldly recast the question of virtue in terms of what we now
call empathy (but which he called sympathy). Smith argued that we
are good to each other because empathy allows us to imagine both
the pleasure and the suffering experienced by our fellow beings.
Even when alone, he suggested, our morality comes from adopting the
perspective of an imagined "impartial spectator."
This notion-which caused consternation among conventional
Christians because it meant that we were virtuous because of how we
felt rather than because of religious inspiration or authority-came
to mind as I was reading an eloquent new book called "Soul Dust,"
by my friend the psychologist and philosopher Nick Humphrey.
To explain consciousness, Mr. Humphrey also invokes a sort of
impartial spectator. In doing so, he rescues an idea that has long
been thought a simple fallacy: the notion of perception as a sort
of movie playing inside our heads, in the so-called Cartesian
theater. As critics have asked, who or what, exactly, is supposed
to be watching this long-running flick?
Erik Johansson
The impossible Penrose triangle in a photo illustration.
Mr. Humphrey's intriguing conclusion is that your mind does
indeed stage "a theatrical show in order to influence the judgment
of another part of your brain." Optical illusions such as the
Penrose triangle (see the picture above) demonstrate that you do
"create" an imagined reality out of the raw material of vision,
what Mr. Humphrey calls a "magical mystery show that you lay on for
yourself," yourself being the rest of the brain.
The genius of "Soul Dust" is to attempt an explanation of both
how this is done and why it evolved. Mr. Humphrey's suggestion is
that animals first acquired an ability to sense the world and to
respond to sensations: When they felt pain (or pleasure), they
withdrew (or extended) the affected body part. They then acquired
the neural capability to monitor their own responses and,
gradually, to produce a virtual internal representation of that
response. Now there was an event in the brain called "paining,"
parallel to the real sensation of pain, or "redding," experienced
when looking at a red tomato.
So consciousness, Mr. Humphrey believes, comes from our way of
mentally re-enacting what happens at our body's surface. Based on
rhythmic patterns of activity in our neurons, he even tries to
explain what the physical manifestation of this phenomenon might
resemble in the brain. Nonetheless, he admits that because we don't
know exactly what we are looking for, we may still fail to
recognize the particular electrical patterns that signify a
conscious thought, even if they are right in front of our brain
scanners.
But why this show? What is the point of being conscious? Mr.
Humphrey made his name many years ago with a famous essay on the
evolutionary function of intelligence, arguing that it emerged
through natural selection not to solve physical puzzles, as many
assume, but to solve social ones-to read minds. Here he attempts a
similar explanation for why the impartial spectator of
consciousness is watching a magical mystery show. His answer sounds
startlingly unscientific, even spiritual: to impress the soul.
What he means is that being enchanted by the magic of experience
provides a reason to live. Rather than being an aid to survival,
consciousness provides an essential incentive to survive.
Enchantment is itself "the biological advantage of being
awestruck." Or, as the poet and Pooh creator A.A. Milne put it,
"It's awful fun to be born at all."
I am not fully persuaded by this last part of the argument-I
prefer to think that the evolutionary advantage of consciousness
has to do with the benefits of imagining and influencing future
events-but it's exhilarating to see this crucial question about our
existence answered with such intellectual breadth. Scientists are
often accused these days of overlooking the awe and wonder of the
world, so it's exciting when a philosopher puts that magic at the
very heart of a scientific hypothesis.