The final essay by neurologist Oliver Sacks
Evolution, creativity, time, consciousness… an endless passion for science,
And a moving metaphor for humanity!

Endless positivity toward humanity and keen insight into the world
A record of the endless flow of the heart, embracing people, animals, and plants…


"The River of Consciousness" is the final collection of essays by neuroscientist Oliver Sacks, which unravels the wondrous scientific mysteries of the people, animals, and plants living in this world and depicts them as metaphors for humanity and human life.
This book is a selection of manuscripts personally selected by Oliver Sacks just before he died of metastatic cancer in August 2015, and it became his final gift to his readers.


The ten essays included in "River of Consciousness" are manuscripts published in the New York Times and other publications during Oliver's lifetime.
In this book, with boundless curiosity and extensive knowledge, he unfolds scientific mysteries on topics such as evolution, creativity, time, and consciousness from lower animals to humans in an engaging way.
Some stories are autobiographical essays, while others are essays that unravel profound scientific research cases.
And he introduces in detail the writings and research value of the great scientists he always admired (Darwin, Freud, William James, etc.).
We introduce the lesser-known achievements and anecdotes of Charles Darwin, who presented the best evidence for the theory of evolution through his study of flowers; Freud, a neurologist who tirelessly studied the mysterious behavior of humans; and William James, who focused on the empirical specificity of time, memory, and creativity.
The American magazine [Science] said, “If I had to describe the feeling of reading the essays in this book in one word, it would be ‘like looking into a constantly flowing stream.’”
“As the water flows and lifts the pebbles, unexpected aspects appear underneath,” he commented.

The concept of 'eternity' and the power of 'change, each small and undirected, but accumulating to create a new world (a world of incredible richness and variety)' were addictive.
Evolution has provided profound meaning and satisfaction to most people (something that belief in a divine plan has not).
The world that was once shrouded in a veil now has a transparent window through which we can look into the entire history of life.
The idea that evolution might have proceeded differently—that dinosaurs might still roam the Earth and humans might not have evolved yet—has puzzled me.
As a result, life felt more precious and like a wonderful ongoing adventure (Stephen Jay Gould called it a glorious accident).
Our lives are not fixed or predetermined, but are always susceptible to change and new experiences.
--- p.35~36

I am delighted that through Darwin I learned about my biological uniqueness, my biological history, and my biological kinship with other life forms.
This knowledge, taking root in my heart, makes nature feel like my home, and (apart from the role assigned to me in human civilization) gives me a sense of my own unique biological significance.
Animal life is far more complex than plant life, and human life is far more complex than that of any other animal, but all living things have their own biological significance.
And the origin of this biological meaning goes back to Darwin's insight into the meaning of flowers through his continuous study of plants.
I vaguely understood its meaning a long time ago in a garden in London.
--- p.37

We humans move at a relatively constant pace, but some people move a little faster and some move a little slower.
Even for one person, energy and engagement can vary depending on the time of day.
Also, when we are young, we are energetic, move a little quickly, and live briskly, but as we age, our movement speed and reaction time gradually slow down.
However, at least for ordinary people (in normal circumstances), these speeds are very limited.
There is no significant difference in reaction time between the elderly and the young, or between world-class athletes and recreational athletes.
The same is true for basic mental functions, such as computation, cognition, and visual association, where the top speeds do not differ significantly.
The dazzling performances of chess masters, the lightning-quick calculations of mental arithmetic masters, the performances of virtuosos, and the skills of other greats are due to their extensive knowledge, memorized patterns and strategies, and incredibly sophisticated techniques, not to their basic neural speed.
--- p.70

In The Voyage of the Beagle, Darwin described how an octopus in a tidal pool interacted with him, initially with wariness, later with curiosity, and even with playfulness.
Octopuses can be quite tame, and their keepers often develop a sense of empathy and a certain mental and emotional closeness to them.
There is much debate as to whether we can use the term consciousness for cephalopods.
However, no one would deny that dogs have a meaningful individual consciousness.
So why can't we acknowledge the octopus's equally powerful consciousness? --- p.88

There seems to be no mechanism in our minds or brains to verify the veracity of memories (or, at least, the existence of the characters appearing in them).
We have no direct access to historical truth, and our feelings and claims about truth depend equally on our senses and imagination.
Just like Helen Keller did.
There is no way to directly transmit or record events occurring in the world to the brain; they can only be filtered and reconstructed through highly subjective methods.
However, each person has a different method of filtering and reconstructing, and even when looking at one person, it is often refiltered and reinterpreted each time they recall it later.
So all we have is narrative truth, and the stories we tell others and ourselves are constantly being recategorized and refined.
This subjectivity is inherent in the very nature of memory, and this subjectivity originates from the foundations and mechanisms of the brain we possess.
It is truly remarkable that, despite this, major errors are relatively rare, and our memories are, for the most part, robust and reliable.
--- p.133~134

The impromptu invention of mishearing is sometimes imbued with a certain style or wit, which reflects to some extent the interests and experiences of the listener.
So rather than feeling embarrassed or uncomfortable about mishearing, I tend to enjoy it.
At least to my ears, 'cancer history' can be translated as 'Cantor's career' (Cantor is one of my favorite mathematicians), tarot cards as pteropods, grocery bags as poetry bags, all-or-noneness as oral numbness, porch as Porsche, and the simple phrase "Christmas Eve" can be translated as a request: "Kiss my feet!"
--- p.140~141

What is particularly noteworthy in Susan Sontag's account of her reading journey (she offered a similar account of primal creativity) is that "young souls, with their immense energy, enthusiasm, enthusiasm, and love, crave intellectual role models and tend to hone their craft by imitating them."
She had extensive knowledge of East and West, past and present, and the 'diversity of human nature and experience', and at some point, this knowledge became the driving force that led her to write her own work.
--- p.145~146

True originality requires not only conscious preparation and training, but also unconscious preparation, a process called the incubation period (or maturation period).
The incubation period is essential for integrating and digesting available resources and influences in the subconscious, reorganizing and synthesizing them into something of one's own.
--- p.155

Human consciousness gives thematic and personal continuity to the consciousness of every individual.
I'm sitting in a cafe on 7th Avenue writing this, watching the world go by.
My attention and focus flicker here and there, watching a girl in a red dress walk by, a man walk away with his funny-looking dog, and the sun finally breaking through the clouds.
But other than those things, there are also things that catch my attention unintentionally.
The sound of car horns, the smell of cigarette smoke, the glow of nearby streetlights… .
All these events caught my attention for a while.
But why, out of a thousand possible perceptions, do I focus solely on those? Perhaps it's due to reflection, memory, and association.
Consciousness is always active and selective, so it informs my choices and influences my perceptions.
So every emotion and meaning becomes uniquely mine.
Therefore, what I am looking at now is not just 7th Avenue, but 'my own 7th Avenue', which has my own individuality and identity added to it.
--- p.196~197

If you get caught up in the details, you can end up missing the forest for the trees.
Therefore, neuroscientists must not neglect the effort to reassemble the details and view them from the perspective of a coherent whole.
To do this, it is necessary to understand determinants at all levels, from the neurophysiological level to the psychological level and even the sociological level.
We must also consider the ongoing and interesting interactions between various determinants.
--- p.208

For us to embrace a new idea, it is not enough to grasp or understand something instantly; our minds must be able to receive and retain it.
To do that, we must first allow ourselves to encounter new ideas.
That is, we must create mental spaces and categories (with potential relevance to new ideas) and then bring new ideas into full and stable consciousness.
Then you have to give them conceptual form and hold them in your mind.
Even if it conflicts with one's existing concepts, beliefs, and categories.
This process of accommodation and securing mental space determines whether an idea or discovery will capture the public's attention and bear fruit, or whether it will fade and be forgotten, never bearing fruit and disappearing.

--- p.220~221