98 | SCIENTIFIC AMERICAN | SPECIAL EDITION | WINTER 2022
I’ve been brooding over these sorts of puzzles a lot
lately, even more than usual. In 2020 I released a book
entitled Pay Attention: Sex, Death, and Science, a
stream-of-thought account of a day in my life. Or rath-
er, in the life of my fictional alter ego, Eamon Toole, a
“divorced science writer and professor struggling to re-
main rational while buffeted by fears and desires.” As
soon as I send a book out into the world, I compulsive-
ly think of things I should have put in it.
Also, my ongoing attempt to learn quantum me-
chanics has mystified my world, inner and outer. So, I’d
like to offer a few thoughts (second thoughts? after-
thoughts?) about thoughts, the most inescapable and
maddeningly elusive features of our existence.META-THOUGHTS AND
THOUGHTLESS THOUGHTS
a note on terms. James coined the phrases “stream
of thought” and “stream of consciousness” and some-
times used them interchangeably, but I distinguish
thoughts from consciousness in the following way:
Thoughts are the contents of consciousness, including
fears, fantasies, recollections, realizations, delibera-
tions, decisions and all the other flora of subjective ex-
perience. If consciousness is the medium, thoughts are
the message.
I also like the easy self-referentiality of “thoughts
about thoughts,” which captures a deep truth about us.
We are what Douglas Hofstadter calls self-generating
“strange loops,” akin to M. C. Escher’s famous drawingof two hands drawing each other. (Who draws the draw-
er?) Thoughts spring from thoughts and—in ways still
beyond our ken—from our brains, which contain rough-
ly 100 billion neurons linked by one quadrillion synaps-
es, each of which processes an average of 10 electro-
chemical signals, or action potentials, every second.
If you equate action potentials with the operations
of a computer, as many neuroscientists do, then the
brain carries out 10 quadrillion operations in a typical
second. That approaches the speed of the world’s fast-
est supercomputers, and the brain may perform expo-
nentially more calculations via processes other than ac-
tion potentials. The result of all this activity is that brains
churn out thoughts as ceaselessly as hearts pump blood.
As James puts it, thoughts are “continuous,” they
“flow,” they keep coming even when we pay no atten-
tion to them, and they keep changing; no thought is pre-
cisely like another. James thus doubts whether psychol-ogists can reduce the human mind to a mental equiva-
lent of atoms as physicists have done with matter.
With some effort, I can direct my thoughts, focus
them, but they often seem to have a will of their own.
They swerve this way or that for reasons obscure to me,
a tendency that Buddhists disparage as “monkey mind.”
When we do notice a thought and reflect on it—perhaps
to convey it to ourselves or to others—we instantly trans-
form it, turning it into a different, higher-order thought.
Call it a meta-thought, a thought about a thought.
Meta-thoughts—the thoughts I express to myself
and to others through writing and speech—are my
bread and butter. I make my living off them. But they
constitute an infinitesimal fraction of my thoughts. The
vast majority are unformed, incoherent, inexpressible,
and they come and go without my dwelling on them.
You might call them thoughtless thoughts. Thoughtless
thoughts are what course through your head when no
one is watching you, not even you.CONSCIOUSNESS WITHOUT THOUGHT?
i once tried to teach meditation to a class of
stressed-out freshmen. I told them to close their eyes,
still their minds and stop thinking. After 10 minutes of
silence, I asked how many had succeeded in thinking
of nothing. To my surprise, about half raised their
hands. I didn’t believe them. Even freshmen always
have thoughts, whether or not they notice them.
Is thoughtless consciousness possible? Yes, accord-
ing to religious scholar Robert Forman, a veteran med-
itator. He claims that he and others
have achieved “pure conscious-
ness,” a mystical state devoid of any
specific thoughts. You are conscious
but not conscious of anything. Con-
sciousness without content strikes
me as a contradiction, an oxymo-
ron, like a book without words or
a film without images. And how
would you know you’re in a state of
pure consciousness? How would
you remember it? Even Forman admits that states of
pure consciousness, if they exist, are rare.
Meditation is touted as a route to knowledge of your
deepest self, your innermost thoughts. I’ve had delight-
ful experiences meditating, especially on a silent retreat
in 2018. But meditation and other contemplative tech-
niques are designed to control and suppress thoughts
rather than to understand them. Meditation is self-
brainwashing aimed at taming your monkey mind. I
don’t want to tame my monkey mind; I want to study
it, to comprehend its antics.
Although we may not notice them and may even
deny their existence, thoughtless thoughts are always
there, underpinned by our brains’ incessant chatter.
Without thoughtless thoughts, we would lack meta-
thoughts. Thoughtless thoughts are the dark matter of
our minds, giving shape via hidden mechanisms to what
is observable, visible, luminous in our inner cosmos.THOUGHTS ARE “CONTINUOUS,” THEY “FLOW,” THEY
KEEP COMING EVEN WHEN WE PAY NO ATTENTION
TO THEM, AND THEY KEEP CHANGING; NO THOUGHT
IS PRECISELY LIKE ANOTHER.