“The mind is its own place,” wrote Milton, “and in it self can make a Heav’n of Hell, a Hell of Heav’n.” But in an age when machines can simulate, with the sheer force of computation, mind-things like poems, is the mind still a sovereign place? What heavenly and hellish creations can it alone make that no algorithm can reproduce or mimic?

I read in Milton’s words the intimation that the mind makes meaning, and meaning — which is different from information, different even from knowledge — is uncomputable. Meaning might be the last stalwart of human consciousness in the age of AI — the supreme existential yearning irreducible to computation, the great creative restlessness that foments all our poems and our passions.

The poetic neurologist Oliver Sacks (July 9, 1933–August 30, 2015) takes up these questions in a prescient April 1993 New York Review of Books essay occasioned by the Nobel-winning neuroscientist Gerald Edelman’s book Bright Air, Brilliant Fire: On The Matter Of The Mind but, like every great book review, soaring far beyond the book itself and into the broader questions of consciousness, the nature of the mind, and what it means to be human.

Reviewing the surge of literature on the science of mind and matter, Sacks laments that “beneath the enthusiasm about scientific developments, there is a certain thinness, a poverty and unreality compared to what we know of human nature, the complexity and density of the emotions we feel and of the thoughts we have.” In a sentiment reminding us how miraculous it is that a cold cosmos kindled consciousness at all, he writes:

We read excitedly of the latest chemical, computational, or quantum theory of mind, and then ask, “Is that all there is to it?”

With an eye to his own excitement upon first encountering Norbert Wiener’s pioneering cybernetics in the late 1940s, with its staggering insistence that “we are not stuff that abides, but patterns that perpetuate themselves,” and the generation of reckonings with logical automata and nerve nets that it inspired, he recounts thinking, like many did, that humanity was on “the verge of computer translation, perception, cognition; a brave new world in which ever more powerful computers would be able to mimic, and even take over, the chief functions of brain and mind.” And yet, as a neurologist who has devoted his life to the inner workings of enfleshed human minds, he cautions:

We must indeed be very cautious before we allow that any artifact is (except in a superficial sense) “mind-like” or “brainlike”… If we are to have a model or theory of mind as this actually occurs in living creatures in the world, it may have to be radically different from anything like a computational one. It will have to be grounded in biological reality, in the anatomical and developmental and functional details of the nervous system; and also in the inner life or mental life of the living creature, the play of its sensations and feelings and drives and intentions, its perception of objects and people and situations, and, in higher creatures at least, the ability to think abstractly and to share through language and culture the consciousness of others.

In a sentiment he would later develop in his insightful writing on narrative memory as the pillar of the self, he adds:

Above all such a theory must account for the development and adaptation peculiar to living systems. Living organisms are born into a world of challenge and novelty, a world of significances, to which they must adapt or die. Living organisms grow, learn, develop, organize knowledge, and use memory in a way that has no analogue in the nonliving. Memory itself is characteristic of life. And memory brings about a change in the organism, so that it is better adapted, better fitted, to meet environmental challenges. The very “self” of the organism is enlarged by memory.

Reflecting on Edelman’s work, Sacks considers the body as the ultimate representation of the self in consciousness, throwing a prescient stick in the spokes of ChatGPT:

To become conscious of being conscious… systems of memory must be related to representation of a self.

What is needed, Sacks observes, is a new theory that recognizes our mental life as more than the sum of computational processes — “a theory of self-organization and emergent order at every level and scale, from the scurrying of molecules and their micropatterns in a million synaptic clefts to the grand macro-patterns of an actual lived life.” Such a theory of mind can only be biological and not mechanistic — an increasingly urgent idea in our present era of disembodied AIs churning out increasingly convincing simulacra of consciousness, yet remaining forever severed from the pulsating totality that is life.

Much of our lust for artificial intelligence stems from what Sacks calls in an even older essay “our almost irresistible desire to see ourselves as being somehow above nature, above the body” — a desire channeled throughout the long history of our damaging dualism, from Plato to Descartes to the very notion of artificial intelligence. Spinoza threw down the first great gauntlet at it with his insistence that our entire conscious experience requires we be understood as embodied beings, for “the body can, by the sole laws of its nature, do many things which the mind wonders at.” The sum total of those things is what we might call experience, and it becomes the lens through which we comprehend — which is different from compute — the world:

The world does not have a predetermined structure: our structuring of the world is our own — our brains create structures in the light of our experiences… Through this structuring and restructuring, the infant, the growing individual, constructs a self and a world.

[…]

It is characteristic of a creature, in contrast to a computer, that nothing is ever precisely repeated or reproduced; that there is, rather, a continual revision and reorganization of perception and memory, so that no two experiences (or their neural bases) are ever precisely the same. Experience is ever-changing, like Heraclitus’ stream. This streamlike quality of mind and perception, of consciousness and life, cannot be caught in any mechanical model — it is only possible in an evolving creature… One is not an immaterial soul, floating around in a machine. I do not feel alive, psychologically alive, except insofar as a stream of feeling — perceiving, imagining, remembering, reflecting, revising, recategorizing runs through me. I am that stream — that stream is me.

Consciousness thus emerges not as an operation of the mind but as an embodied interaction between mind and world — a dynamic flow of exchanges in which the whole organism, not just the brain, participates and, in the act of participation, creates itself. (The neuroscientist Antonio Damasio has since made a compelling case for consciousness not as a brain function but as a full-body phenomenon, and other work has demonstrated again and again that “our mind is body-bound.”)

Sacks writes:

During the development of the fetus, a unique neuronal pattern of connections is created, and then in the infant experience acts upon this pattern, modifying it by selectively strengthening or weakening connections between neuronal groups, or creating entirely new connections.

Thus experience itself is not passive, a matter of “impressions” or “sensedata,” but active, and constructed by the organism from the start. Active experience “selects,” or carves out, a new, more complexly connected pattern of neuronal groups, a neuronal reflection of the individual experience of the child, of the procedures by which it has come to categorize reality.

Eventually, these distinct neuronal circuits synchronize with each other to shape “the inner life, the mind, the behavior of the creature.” With an eye to this and other strong evidence for a biological basis of consciousness, he writes:

From Boole, with his “Laws of Thought” in the 1850s, to the pioneers of Artificial Intelligence at the present day, there has been a persistent notion that one may have an intelligence or a language based on pure logic, without anything so messy as “meaning” being involved… This is not the case, and cannot be the case.

Our search for meaning, Sacks intimates, will be forever part of the human organism’s experience of optimal functioning — an experience, to me, qualitatively different from anything an artificial intelligence can approximate, to the extent that it can even have experience at all. In a passage that strikes me as the supreme refutation of ChatGPT’s bid for consciousness, he writes:

That feeling we have when we are functioning optimally, of a swift, effortless, complex, ever-changing, but integrated and orchestrated stream of consciousness… coincides with the sense that this consciousness is ours, and that all we experience and do and say is, implicitly, a form of self-expression, and that we are destined, whether we wish it or not, to a life of particularity and self-development; it coincides, finally, with our sense that life is a journey — unpredictable, full of risk and uncertainty, but, equally, full of novelty and adventure, and characterized (if not sabotaged by external constraints or pathology) by constant advance, an ever deeper exploration and understanding of the world.

Again and again, the correlates of consciousness root it in the life of the body, the pulse-beat of experience hungry for meaning — something lacking in a machine of even the most astonishing computational capacity. In a lyrical antidote to millennia of dualism and a maelstrom of trendy hyperboles about the future of AI, Sacks writes:

We are not incoherent, a bundle of sensations, but a self, rising from experience, continually growing and revised. The brain is not a bundle of impersonal processes, an “It,” with the “mind,” the “self,” hovering mysteriously above it. It is a confederation, an organic unity, of innumerable categorizations, and categorizations of its own activities, and from these, its self-reflection, there arises consciousness, the Mind, a metastructure… built upon the real worlds in the brain… Through experience, education, art, and life, we teach our brains to become unique. We learn to be individuals. This is a neurological learning as well as a spiritual learning.

Complement with Meghan O’Gieblyn on consciousness and our search for meaning in the age of AI, then revisit Oliver Sacks on the three essential elements of creativity, the psychology of writing, and mortality and the meaning of life.