Can you
explain, in simple terms, what you mean by panpsychism?
In our standard
view of things, consciousness exists only in
the brains of
highly evolved organisms, and hence consciousness exists only in
a tiny part of the universe and only in very recent history.
According to
panpsychism, in contrast, consciousness pervades the universe
and is a fundamental feature of it.
This doesn't
mean that literally everything is conscious. The basic
commitment is that the fundamental constituents of reality -
'perhaps electrons and quarks' - have incredibly simple forms of
experience.
And the very
complex experience of the human or animal brain is somehow
derived from the experience of the brain's most basic parts.
It might be
important to clarify what I mean by "consciousness," as that
word is actually quite ambiguous.
Some people use it to mean
something quite sophisticated, such as self-awareness or the
capacity to reflect on one's own existence.
This is
something we might be reluctant to ascribe to many nonhuman
animals, never mind fundamental particles. But when I use the
word consciousness, I simply mean experience:
pleasure,
pain, visual or auditory experience, et cetera.
Human beings
have a very rich and complex experience; horses less so; mice
less so again.
As we move to
simpler and simpler forms of life, we find simpler and simpler
forms of experience. Perhaps, at some point, the light switches
off, and consciousness disappears.
But it's at
least coherent to suppose that this continuum of consciousness
fading while never quite turning off carries on into inorganic
matter, with fundamental particles having almost unimaginably
simple forms of experience to reflect their incredibly simple
nature.
That's what
panpsychists believe...
You write that
you come to this idea as a way of solving a problem in the way
consciousness is studied. What, in your mind, is the problem?
Despite great
progress in our scientific understanding of the brain, we still
don't have even the beginnings of an explanation of how complex
electrochemical signaling is somehow able to give rise to the
inner subjective world of colors, sounds, smells and tastes that
each of us knows in our own case.
There is a deep
mystery in understanding how what we know about ourselves from
the inside fits together with what science tells us about matter
from the outside.
While the
problem is broadly acknowledged, many people think we just need
to plug away at our standard methods of investigating the brain,
and we'll eventually crack it.
But in my new
book, I argue that the problem of consciousness results from the
way we designed science at the start of the scientific
revolution.
A key moment in
the scientific revolution was Galileo's declaration that
mathematics was to be the language of the new science,
that the new science was to have a purely quantitative
vocabulary.
But Galileo
realized that you can't capture consciousness in these terms, as
consciousness is an essentially quality-involving
phenomenon. Think about the redness of a red experiences or the
smell of flowers or the taste of mint. You can't capture these
kinds of qualities in the purely quantitative
vocabulary of physical science.
So Galileo
decided that we have to put consciousness outside of the domain
of science; after we'd done that, everything else could be
captured in mathematics.
This is really
important, because although the problem of consciousness is
taken seriously, most people assume our conventional scientific
approach is capable of solving it.
And they think
this because they look at the great success of physical science
in explaining more and more
of our universe and conclude that
this ought to give us confidence that physical science alone
will one day explain consciousness.
However, I
believe that this reaction is rooted in a misunderstanding of
the history of science.
Yes, physical
science has been incredibly successful. But it's been successful
precisely because it was designed to exclude consciousness...
If Galileo were
to time travel to the present day and hear about this problem of
explaining consciousness in the terms of physical science, he'd
say,
"Of course,
you can't do that. I designed physical science to deal with
quantities, not qualities."
How does
panpsychism allow you to approach the problem differently?
The starting
point of the panpsychist is that physical science doesn't
actually tell us what matter is...!
That sounds
like a bizarre claim at first; you read a physics textbook, you
seem to learn all kinds of incredible things about the nature of
space, time and matter.
But what philosophers of science have
realized is that physical science, for all its richness, is
confined to telling us about the behavior of matter,
what it does.
Physics tells
us, for example, that matter has mass and charge.
These
properties are completely defined in terms of behavior, things
like,
attraction, repulsion, resistance to acceleration.
Physics
tells us absolutely nothing about what philosophers like to call
the intrinsic nature of matter:
what matter is, in and
of itself...
So it turns out
that there is a huge hole in our scientific story.
The proposal of
the panpsychist is to put consciousness in that hole.
Consciousness, for the panpsychist, is the intrinsic nature of
matter.
There's just
matter, on this view, nothing supernatural or spiritual. But
matter can be described from two perspectives.
Physical science
describes matter "from the outside," in terms of its behavior.
But matter
"from the inside" - 'i.e., in terms of its intrinsic nature -
'is constituted of forms of consciousness.
What this
offers us is a beautifully simple, elegant way of integrating
consciousness into our scientific worldview, of marrying what we
know about ourselves from the inside and what science tells us
about matter from the outside.
What are the
objections to this idea that you hear most frequently? And how
do you respond?
Of course, the
most common one is "That's just crazy...!"
But many of our
best scientific theories are wildly counter to common sense, too:
for example, Albert Einstein's theory that time slows down
when you travel very fast or
Charles Darwin's theory that our
ancestors were apes...
At the end of
the day, you should judge a view not by its cultural
associations but by its explanatory power.
Panpsychism
gives us a way of resolving the mystery of consciousness, a way
that avoids the deep difficulties that plague more conventional
options.
Do you foresee
a scenario in which panpsychism can be tested?
There is a
profound difficulty at the heart of the science of
consciousness:
consciousness is unobservable...
You can't look
inside an electron to see whether or not it is conscious. But
nor can you look inside someone's head and see their feelings
and experiences.
We know that
consciousness exists not from observation and experiment but by
being conscious.
The only way we
can find out about the consciousness of others is by asking
them:
I can't directly perceive your experience, but I can ask
you what you're feeling.
And if I'm a
neuroscientist, I can do this while I'm scanning your brain to
see which bits light up as you tell me what you're feeling and
experiencing.
In this way,
scientists are able correlate certain kinds of brain activity
with certain kinds of experience.
We now know
which kinds of brain activity are associated with feelings of
hunger, with visual experiences, with pleasure, pain, anxiety,
et cetera.
This is really
important information, but it's not itself a theory of
consciousness.
That's because what we ultimately want from a
science of consciousness is an explanation of those
correlations.
Why is it
that, say, a certain kind of activity in the hypothalamus is
associated with the feeling of hunger?
Why should
that be so?
As soon as you
start to answer this question, you move beyond what can be,
strictly speaking, tested, simply because consciousness is
unobservable.
We have to turn
to philosophy...
The moral of
the story is that we need both
the science and the philosophy to
get a theory of consciousness.
The science gives us correlations
between brain activity and experience.
We then have to
work out the best philosophical theory that explains those
correlations.
In my view, the
only theory that holds up to scrutiny is panpsychism...
