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It’s Me!

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Mathias Gatza (Ingo Niermann)

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Inhalt

David Pearce

Nonmaterialist Physicalism: An Experimentally Testable Conjecture

Ingo Niermann

Wie die Welt sich selbst ausdenkt

David Pearce
NONMATERIALIST PHYSICALISM
–
AN EXPERIMENTALLY TESTABLE CONJECTURE

You’re nothing but a pack of neurons.
Francis Crick

ABSTRACT

Mankind’s most successful story of the world, natural science, leaves the existence of consciousness wholly unexplained. The phenomenal binding problem deepens the mystery. Neither classical nor quantum physics seem to allow the binding of distributively processed neuronal micro-experiences into unitary experiential objects apprehended by a unitary phenomenal self. This paper argues that if physicalism and the ontological unity of science are to be saved, then we will need to revise our notions of both 1) the intrinsic nature of the physical and 2) the quasi-classicality of neurons. In conjunction, these two hypotheses yield a novel and bizarre but experimentally testable prediction of quantum superpositions (“Schrödinger’s cat states”) of neuronal feature-processors in the central nervous system (CNS) at sub-femtosecond timescales. An experimental protocol using in vitro neuronal networks is described to confirm or empirically falsify this conjecture via molecular matter-wave interferometry.

CONTENTS

1. Introduction

2. Preliminary Definitions

3. Criteria for a Scientifically Adequate Theory of Conscious Mind

4. Challenges to Nonmaterialist Physicalism

5. Phenomenal Binding Is the Hallmark of Mind

6. Can Physicalism be Saved?

7. What Is It Like To Be Schrödinger’s Cat?

8. Schrödinger’s Neurons: The Experimental Protocol

9. Femto-Mind Meets Quantum Darwinism

10. A Mendeleev Table for Qualia?

11. Towards a Post-Galilean Science of Mind

12. Summary and Prospects

1. INTRODUCTION

Natural science promises a complete story of the universe. No “element of reality”[1] should be missing from the mathematical formalism of physics, i.e., relativistic quantum field theory[2] or its more speculative extensions. On pain of magic, every gross property of the natural world must be theoretically reducible to fundamental physics. The Standard Model in physics is experimentally well tested. Within its conceptual framework, consciousness would seem not only causally impotent but physically impossible. Hence the “explanatory gap”[3] and the “Hard Problem”[4] of consciousness.

In recent years, a minority of researchers have proposed that the Hard Problem is an artifact of materialist metaphysics. Contra Kant,[5] but following Schopenhauer,[6] Bertrand Russell,[7] Grover Maxwell,[8] Michael Lockwood,[9] Galen Strawson[10] et al., the new idealists conjecture that the phenomenology of one’s mind reveals the intrinsic nature of the physical—the elusive “fire” in the equations about which physics is silent (as Stephen Hawking says).[11] Mathematical physics yields an exhaustive description of the relational-structural properties of the world. This description may ultimately be encoded by the universal wavefunction of post-Everett[12] quantum mechanics. However, our presupposition that the intrinsic character of the physical lacks phenomenal properties is an additional metaphysical assumption. The assumption is hugely plausible but it is not a scientific discovery. Perhaps most tellingly, the only part of the “fire” in the equations to which one ever enjoys direct access, i.e., one’s own consciousness, discloses phenomenal properties that are inconsistent with a materialist ontology. For reasons unexplained, the natural world contains first-person facts. The world supports at least one non-zombie. And natural science gives no reason to believe that one is special.

Untestability cuts both ways. Any conjecture that superpositions of the world’s fundamental quantum fields—and, presumably, fundamental macroscopic quantum phenomena such as superconductors or superfluid helium—are intrinsically experiential would seem unfalsifiable too: just speculative metaphysics. Rather surprisingly, we shall see this isn’t the case.

2. PRELIMINARY DEFINITIONS

Both physics and philosophy are jargon-ridden. So let us first define some key concepts.

Both consciousness and physical are contested terms. Accurately if inelegantly, consciousness may be described following Nagel as the subjective “what-it’s-like-ness” of experience. Academic philosophers term such self-intimating “raw feels” qualia, whether macroqualia or microqualia. The minimum unit of consciousness (or psychon) has been claimed variously to be the entire universe, a person, a subpersonal neural network, an individual neuron, or the most basic entities recognised by quantum physics. In The Principles of Psychology (1890), American philosopher and psychologist William James christened these phenomenal simples “primordial mind-dust”. This paper conjectures first that our minds consist of ultrarapidly decohering neuronal superpositions in strict accordance with unmodified quantum physics without the mythical collapse of the wavefunction; second, that natural selection has harnessed the properties of these neuronal superpositions so our minds run phenomenally bound world-simulations; and it then predicts that with enough ingenuity the nonclassical interference signature of these conscious neuronal superpositions will be independently experimentally detectable (see section 8 below) to the satisfaction of the most incredulous critic.

The physical may be contrasted with the supernatural or the abstract; dualists and epiphenomenalists contrast the physical with the mental. The current absence of any satisfactory positive definition of the physical leads many philosophers of science to adopt instead the via negativa. Thus some materialists have sought stipulatively to define the physical in terms of an absence of phenomenal experience. However, these a priori definitions of the physical beg the question.

Physicalism is sometimes treated as the formalistic claim that the natural world is exhaustively described by the equations of physics and their solutions. Beyond these structural-relational properties of matter and energy, the term is also often used to make an ontological claim about the intrinsic character of whatever the equations describe. This intrinsic character, or metaphysical essence, is typically assumed to be nonphenomenal. Strawsonian physicalists and other nonmaterialist physicalists dispute any such assumption. Traditional reductive physicalism proposes that the properties of larger entities are determined by properties of their physical parts. If the wavefunction monism of post-Everett quantum mechanics assumed here is true, then the world does not contain discrete physical parts as understood by classical physics. If contemporary physicalism is true, reductionism is false.

Materialism is the metaphysical doctrine that the world is made of intrinsically nonphenomenal “stuff”. Materialism and physicalism are often treated as cousins and sometimes as mere stylistic variants, with physicalism used as a nod to how bosonic fields, for example, are not matter. Physicalistic materialism is the claim that physical reality is fundamentally nonexperiential and that the natural world is exhaustively described by the equations of physics and their solutions.

Panpsychism is the doctrine that the world’s fundamental physical stuff also has primitive experiential properties. Unlike the physicalistic idealism explored here, panpsychism doesn’t claim that the world’s fundamental physical stuff is experiential. Panpsychism is best treated as a form of property-dualism.

Epiphenomenalism in philosophy of mind is the view that experience is caused by material states or events in the brain but does not itself cause anything; the causal efficacy of mental agency is an illusion.

For our purposes, idealism is the ontological claim that reality is fundamentally experiential. This use of the term should be distinguished from Berkeleyan idealism, and more generally, from subjective idealism, i.e., the doctrine that only mental contents exist: that reality is mind-dependent. One potential source of confusion of contemporary scientific idealism with traditional philosophical idealism is the use by inferential realists in the theory of perception of the term world-simulation. The mind-dependence of one’s phenomenal world-simulation, i.e., the quasi-classical world of one’s everyday experience, does not entail the idealist claim that the mind-independent physical world is intrinsically experiential in nature—a far bolder conjecture that we nonetheless tentatively defend here.

Physicalistic idealism is the nonmaterialist physicalist claim that reality is fundamentally experiential and that the natural world is exhaustively described by the equations of physics and their solutions. More specifically, the natural world is described by the continuous, linear, unitary evolution of the universal wavefunction of post-Everett quantum mechanics.

The decoherence program in contemporary theoretical physics aims to show in a rigorously quantitative manner how quasi-classicality emerges from the unitary Schrödinger dynamics. Environmentally induced quantum decoherence explains the appearance to observers of wavefunction collapse.

Monism is the conjecture that reality consists of a single kind of “stuff”—be it material, experiential, spiritual, or whatever. Wavefunction monism is the view that the universal wavefunction mathematically represents, exhaustively, all there is in the world. Strictly speaking, wavefunction monism shouldn’t be construed as the claim that reality literally consists of a certain function, i.e., a mapping from some mind-wrenchingly immense configuration space to the complex numbers, but rather as the claim that every mathematical property of the wavefunction, except the overall phase, corresponds to some property of the physical world. Dualism, the conjecture that reality consists of two kinds of “stuff”, comes in many flavours: naturalistic and theological; interactionist and noninteractionist; property and ontological. In the modern era, most scientifically literate monists have been materialists. But to describe oneself as both a physicalist and a monistic idealist is not the schizophrenic word salad it sounds at first blush.

Functionalism in philosophy of mind is the theory that mental states are constituted solely by their functional role, i.e., by their causal relations to other mental states, perceptual inputs and behavioural outputs. Functionalism is often associated with the idea of “substrate-neutrality”, sometimes misnamed “substrate-independence”, according to which minds can be realised in multiple substrates and at multiple levels of abstraction. However, microfunctionalists may dispute substrate-neutrality on the grounds that one or more properties of mind, for example phenomenal binding, functionally implicate the world’s quantum-mechanical bedrock from which the quasi-classical worlds of Everett’s multiverse emerge. Thus this paper will argue that only successive, quantum-coherent, neuronal superpositions at preposterously short timescales can explain phenomenal binding. Without phenomenal binding, no functionally adaptive classical world-simulations could exist in the first instance.

The binding problem,[13] also called the combination problem, refers to the mystery of how the micro-experiences mediated by supposedly discrete and distributed neuronal edge-detectors, motion-detectors, shape-detectors, colour-detectors, etc., can be “bound” into unitary experiential objects (“local” binding) apprehended by a unitary experiential self (“global” binding). Neuro-electrode studies using awake, verbally competent human subjects confirm that neuronal micro-experiences exist. Classical neuroscience cannot explain how they could ever be phenomenally bound. As normally posed, the binding problem assumes rather than derives the emergence of classicality.

Mereology is the theory of the relations between parts and the whole and the relations between part to part within a whole. Scientifically literate humans find it natural and convenient to think of particles, macromolecules, or neurons as having their own individual wavefunctions by which they can be formally represented. However, the manifest nonclassicality of phenomenal binding means that in some contexts we must consider describing the entire mind-brain via a single wavefunction. Organic minds are not simply the mereological sum of discrete, decohered classical parts. Sentient organic brains are not simply the mereological sum of discrete, decohered, classical neurons.

Quantum field theory (QFT) is the formal, mathematico-physical description of the natural world. The world is made up of the states of interacting quantum fields, conventionally nonexperiential in character, that take on discrete values. Physicists use mathematical entities known as wavefunctions to represent quantum states. Wavefunctions may be conceived as representing all the possible configurations of a superposed quantum system. Wavefunction(al)s are complex-valued functionals on the space of field configurations. Wavefunctions in quantum mechanics are sinusoidal functions with an amplitude (a “measure”) and also a phase. The Schrödinger equation describes the time-evolution of a wavefunction.

Coherence means that the phases of the wavefunction are kept constant between the coherent particles, macromolecules or (hypothetically) neurons, while decoherence is the effective loss of ordering of the phase angles between the components of a system in a quantum superposition due to interactions with the environment. Such thermally induced “dephasing” rapidly leads to the emergence—on a perceptual, naive, realist story—of classical, i.e., probabilistically additive, behaviour in the CNS, and also the illusory appearance of separate, noninterfering, organic macromolecules. Hence the discrete, decohered, classical neurons of laboratory microscopy and biology textbooks. Unlike classical physics, quantum mechanics deals with superpositions of probability amplitudes rather than of probabilities; hence the interference terms in the probability distribution. Decoherence should be distinguished from dissipation, i.e., the loss of energy from a system—a much slower, classical effect. Phase coherence is a quantum phenomenon with no classical analogue. If quantum theory is universally true, then any physical system such as a molecule, a neuron, a neuronal network or an entire mind-brain exists partly in all its theoretically allowed states, or configuration of its physical properties, simultaneously in a quantum superposition; informally, a “Schrödinger’s cat state”, a weighted combination of all possible measurement outcomes. Each state is formally represented by a complex vector (technically a ray, or one-dimensional subspace) in the infinite-dimensional analogue of Euclidean space known as Hilbert space. Whatever overall state the nervous system is in can be represented as being a superposition of varying amounts of these particular states (“eigenstates”) where the amount that each eigenstate contributes to the overall sum is termed a component.

The Schrödinger equation is a partial differential equation that describes how the state of a physical system changes with time. The Schrödinger equation acts on the entire probability amplitude, not merely its absolute value. The absolute value of the probability amplitude encodes information about probability densities, so to speak, whereas its phase encodes information about the interference between quantum states. On measurement by an experimenter, the value of the physical quantity in a quantum superposition will naively seem to “collapse” in an irreducibly stochastic manner, with a probability equal to the square of the coefficient of the superposition in the linear combination. If the superposition principle really breaks down in the mind-brain, as traditional Copenhagen positivists still believe, then the central conjecture of this paper is false.

Mereological nihilism, also known as compositional nihilism, is the philosophical position that objects with proper parts do not exist, whether extended in space or in time. Only basic building blocks (particles, fields, superstrings, branes, information, micro-experiences, quantum superpositions, entangled states, or whatever) without parts exist. Such ontological reductionism is untenable if the mind-brain supports macroscopic quantum coherence in the guise of bound phenomenal states because coherent neuronal superpositions describe individual physical states. Coherent superpositions of neuronal feature-detectors cannot be interpreted as classical ensembles of states. Radical ontological reductionism is even more problematic if post-Everett[14] quantum mechanics is correct in its claim that reality is exhaustively described by the time-evolution of one gigantic, universal wavefunction. If such wavefunction monism is true, then talk of how neuronal superpositions are rapidly “destroyed” is just a linguistic convenience because a looser, heavily disguised coherence persists within a higher-level Schrödinger equation (or its relativistic generalisation) that subsumes the previously tighter entanglement within a hierarchy of wavefunctions, all ultimately subsumed within the universal wavefunction.

Direct realism, also known as naive realism, is the prescientific view that the mind-brain is directly acquainted with the external world. In contrast, the world-simulation model[15] assumed here treats the mind-brain as running a data-driven simulation of gross, fitness-relevant patterns in the mind-independent environment. As an inferential realist, the world-simulationist is not committed per se to any kind of idealist ontology, physicalistic or otherwise. However, s/he will understand phenomenal consciousness as broader in scope compared to the traditional perceptual direct realist. The world-simulationist will also be less confident than the direct realist that we have any kind of pretheoretic conceptual handle on the nature of the physical beyond the formalism of theoretical physics—and our own phenomenally bound, physical consciousness.

Classical worlds are what perceptual direct realists call the world. Quantum theory suggests that the multiverse exists in an inconceivably vast cosmological superposition. Yet within our individual perceptual world-simulations, familiar macroscopic objects 1) occupy definite positions (the “preferred basis” problem); 2) don’t readily display quantum interference effects; and 3) yield well-defined outcomes when experimentally probed. Cats are either dead or alive, not dead-and-alive. Or, as one scientific populariser puts it, “Where Does All the Weirdness Go?”[16] This paper argues that the answer lies under our virtual noses, so to speak—though independent physical proof to silence sceptics will depend on next-generation matter-wave interferometry. Phenomenally bound classical world-simulations are the mind-dependent signature of the quantum “weirdness”. Without the superposition principle, no phenomenally bound classical world-simulations could exist and nor could minds. In short, we shouldn’t imagine superpositions of live-and-dead cats but instead think of superpositions of colour-, shape-, edge- and motion-processing neurons. Thanks to natural selection, the content of our waking world-simulations typically appears classical but the vehicle of the simulation that our minds run is inescapably quantum. If the world were classical it wouldn’t look like anything to anyone.

A zombie, sometimes called a philosophical zombie or p-zombie to avoid confusion with its lumbering Hollywood cousins, is a hypothetical organism that is materially and behaviourally identical to humans and other organic sentients but which is not conscious. Philosophers explore the epistemological question of how each of us can know that we aren’t surrounded by p-zombies. Yet we face a mystery deeper than the old sceptical problem of other minds. If our ordinary understanding of the fundamental nature of matter and energy as described by physics is correct, and if our neurons are effectively decohered classical objects as suggested by standard neuroscience, then we all ought to be zombies. Following David Chalmers, this is called the Hard Problem of consciousness.

3. CRITERIA FOR A SCIENTIFICALLY ADEQUATE THEORY OF CONSCIOUS MIND

A scientifically adequate theory of conscious mind must explain:

1) Why consciousness exists at all.

2) How consciousness has the causal power to allow intelligent agents to investigate its own nature.

3) How consciousness can be phenomenally bound in seemingly classically forbidden ways into unitary dynamic objects. In other words, which of the world’s information-processing systems are unitary subjects of experience and which are mere aggregates or “zombies”?

4) Why and how consciousness manifests its diverse textures—ranging from phenomenal colours, sounds, tastes and smells, pains and pleasures, the experience of introspecting a thought-episode, feeling pangs of jealousy, hearing an orchestra play, admiring a sunset, to finding a joke amusing. In our mathematico-physical theory of everything (TOE), where is the information that yields the disparate values of experience?

Finally, 5), any satisfactory scientific theory of consciousness should also offer predictions that are both novel and experimentally falsifiable.

4. CHALLENGES TO NONMATERIALIST PHYSICALISM

David Chalmers[17] identifies two challenges faced by any claim that consciousness discloses the intrinsic nature of the physical:

a) the argument from microphysical simplicity.

b) the argument from structural mismatch.

Let us look at these two challenges in turn.

a) The argument that if physicalistic idealism is true, then “we can expect only a handful of microqualities, corresponding to the handful of fundamental microphysical properties” is intuitively appealing. After all, runs this line of argument, every electron in the world is type-identical to every other electron. Electrons are exceedingly simple. After we have specified the mass, charge and spin of an electron, what else is there to say? An electron “has no hair”. Or more technically, after we have given the four quantum numbers that completely describe the electron, namely its principal quantum number (n), azimuthal quantum number (l), magnetic quantum number (m) and spin quantum number (s), what else is there left to add?

However, in quantum field theory rather than basic quantum mechanics, there are no particles, only fields and field quanta. What we call “particles” by cosy analogy with classical physics are emergent entities supervenient on the underlying quantum fields. So if, instead of a particle-based ontology, the monistic idealist assumes a quantum field-theoretic ontology, then the diverse values of the world’s fundamental fields yield the diverse subjective textures of microqualia, a vast palette of different qualia-field values. All physical systems, including macroscopic neural networks, are quantum fields. To be sure, in our present ignorance we don’t know how to “read off” the diverse values of microqualia from superpositions of the diverse values of the different fundamental fields. We lack any kind of cosmic Rosetta stone. But on this physicalistic idealist conjecture, there is no “element of reality” lacking in the quantum field-theoretic formalism that encodes the world’s fundamental micro-experiences. Algorithmically compressed into mathematical equations, the information encoding the exact textures of qualia-field values just awaits extraction. For in contemporary physics, fields (or indeed superstrings or branes[18]) are defined purely mathematically, even though their experimentally manipulable effects show that the fields are physically real. These fields take a vast range of values (“numbers in space”) with a (conventionally) infinite number of degrees of freedom. Crudely, on this account, “more is different”—micro-experientially different. Critically, these fields are not classical. Overcoming Chalmers’s second challenge to physicalistic idealism, i.e., b), the argument from structural mismatch, turns on recognising that fields in quantum field theory exist in quantum superpositions of states. These quantum superpositions may be microscopic, mesoscopic, or macroscopic; all are subject to the laws of quantum physics.

b) The argument that the “macrophenomenal structure of my visual field is prima facie very different from the macrophysical structure of my brain” seems intuitively obvious too. Yet this intuitive appeal may simply reflect the coarse-grained temporal resolution of our tools for investigating awake/dreaming mind-brains: a resolution of milliseconds not picoseconds, femtoseconds or attoseconds. Appearances of a structural mismatch between neuroscience and phenomenology may be deceptive. There is no experimental evidence for a breakdown of the superposition principle in the mind-brain. What the textbooks describe as synchronous firings of classical neuronal feature-detectors[19] may turn out to be successive quantum-coherent superpositions of the relevant neuronal feature-detectors. We won’t know whether superposition is masquerading to experimental neuroscience as synchrony until advanced interferometry experimentally settles the issue independently. If empirically confirmed, the detection of such sub-femtosecond neuronal superpositions would render a stunningly beautiful result; the experimental confirmation of what sounds naively like unbridled metaphysical speculation.

Let us use a nonbiological analogy. If physicalistic idealism is true, then the macrophenomenal structure of superfluid helium presumably consists of a simple, unvarying, long-lived, irreducible macro-experience: a perfect structural match between formal and subjective properties of the world. Of course, humans will never know what, if anything, it is like to instantiate the wavefunction that describes superfluid helium. But when our experimental apparatus allows probing the CNS at the sub-femtosecond timescales below which scientists such as Max Tegmark posit effectively irreversible thermally induced decoherence, then our classical intuitions may be confounded. On this conjecture, we will find not random quantum “noise” but instead the structural quantum-coherent physical shadows of the bound macroscopic phenomenal objects of everyday experience, all computationally optimised by hundreds of millions of years of evolution to track fitness-relevant patterns in the mind-independent world. This would offer a perfect structural match between the phenomenology of consciousness and our canonical representations of the physical. According to the conjecture here explored, training up our neural networks ensures that some neuronal states of the CNS are less prone to thermally induced decoherence than others. It is these comparatively robust experiential-physical states, most notably the perceptual objects of everyday experience, that experimentalists will detect in the CNS when molecular matter-wave interferometry catches up with theory. So when you report “I can see a chair,” and (on the conventional classical story) synchronous activation of your relevant neuronal feature-detectors occurs, the conjecture will be falsified if the subtle nonclassical neuronal interference effects typically detected are irrelevant “noise”, say a sub-attosecond superposition of the neurons synchronously activated when you see a hippopotamus, for example. In other words, the putative mismatch that Chalmers identifies between the phenomenology of our bound phenomenal minds and the architecture of the brain may turn out to be an artifact of the low temporal resolution of our clumsy tools of investigation.

This is, most certainly, an unintuitive hypothesis. Yet the neurological implausibility of such a fine-grained temporal match should be set against the physical incredibility of the alternatives. From the perspective of natural science, the discovery of a true structural mismatch between physics and phenomenology in the CNS would be more astonishing than the previously unsuspected isomorphism between the phenomenal and the physical canvassed here. Such a rupture in the fabric of reality would spell the end of physicalism—an epistemic catastrophe for the unity of science. Unlike his critics, Chalmers is right to recognise the magnitude of the structural mismatch problem for orthodox materialism and classical panpsychism alike. Chalmers just quits the game too soon. He embraces what must surely count as a counsel of despair: dualism. Monistic physicalism can still be saved. Physicalism would be unsalvageable only if the brain were no more than a networked community of discrete, effectively classical neurons—or their idealist counterpart, i.e., discrete, effectively classical neuronal “mind-dust”—rather than a succession of macroscopic, neuronal superpositions that make up one’s everyday phenomenal world. Monistic physicalism isn’t falsified by a structural mismatch between the three-dimensional space of naive, perceptual realism and conscious mind. Monistic physicalism would be falsified only by a structural mismatch between the bound phenomenology of our minds and the fundamental, high-dimensional space required by the dynamics of the wavefunction. No such mismatch has ever been experimentally demonstrated to date.

5. PHENOMENAL BINDING IS THE HALLMARK OF MIND

The only realities are the separate molecules, or at most cells. Their aggregation into a “brain” is a fiction of popular speech.
William James

The existence of bound phenomenal minds rather than cellular mind-dust suggests that separate molecules and nerve cells are a fiction of classical neuromythology. Solving the binding problem has been perhaps the greatest cognitive achievement of post-Cambrian[20] central nervous systems. Without phenomenal binding, members of the animal kingdom wouldn’t have minds at all—or classical-seeming world-simulations they could navigate. Over the past half-billion or more years, the mind-brains of unprogrammed organic robots have evolved under the pressure of natural selection to run data-driven, cross-modally matched egocentric world-simulations of their local environment in almost real time. The extraordinary computational power of binding is most vividly illustrated in neurological syndromes where local or global phenomenal binding partially breaks down. Patients with simultanagnosia,[21] for example, can see only one phenomenal object at once. Those suffering from cerebral akinetopsia[22] are unable to detect motion. People with florid schizophrenia suffer from the disintegration of a unitary self. Even partial loss of phenomenal binding may be intellectually debilitating and behaviourally catastrophic. Neurotypical minds carry off such computational feats with ease. Unfortunately, a neuroscientific explanation is elusive.

By way of context, the phenomenal binding problem is normally posed roughly as follows: How can what neuroscience suggests are distributively neurally processed edges, colours, shapes, motions etc. be “bound” into unitary experiential objects populating a unitary experiential field instantiated by a fleetingly unitary self in the neural networks of the CNS? Such phenomenal binding would seem impossible for discrete, membrane-bound, quasi-classical neurons—or quasi-classical “mind-dust” on a physicalistic idealist ontology—separated by circa 3.5 nanometre electrical gap-junctions and 20-40 nanometre chemical synapses. Mere synchronous activation of discrete, decohered, classical systems cannot bind—any more than discrete, skull-bound minds each undergoing a pinprick causes the emergence of a global mega-mind in agony, or a musical symphony emerges from discrete, skull-bound minds each instantiating a musical note. Whether causally connected or otherwise, synchronously activated classical “pixels” of experience remain unglued. Phenomenal mind is not a classical phenomenon. Neither are the pseudoclassical world-simulations run by our waking minds. Chalmers is right on that score. Does quantum mind-binding fare any better?

On the face of it, no. Decoherence is among the fastest processes known to experimental physics. By contrast, we normally assume that states of consciousness somehow arise via neural transmission over a timescale of milliseconds. Yet unless, implausibly, quantum theory breaks down in the mind–brain—as in so-called “dynamical collapse” or “hidden variables” theories of quantum mechanics—macroscopic, quantum-coherent states implicating such neurologically distributed cellular processes of feature-processing must exist in the CNS. What is in question is only their character: noise or signal? Classical neuroscience assumes that these neuronal superpositions are irrelevant to consciousness.

To make our point, let’s pose a concrete question. When one apprehends a bound phenomenal object in one’s world-simulation, what does it feel like to instantiate successive, quantum-coherent, macro-superpositions of colour-detector neurons, motion-detector neurons, edge-detector neurons etc. with each macro-superposition in the sequence lasting what theory suggests must be a femtosecond or less? The obvious answer to the question of what it feels like to instantiate such a sequence of neuronal superpositions is “nothing at all”—or perhaps computationally incidental “psychotic noise”—because environment-induced decoherence effectively destroys macroscopic neuronal superpositions in the CNS at sub-femtosecond timescales. Quantum coherence is for all practical purposes irreversibly delocalised into the larger CNS–environment combination though uncontrolled environmental entanglement. On the standard neuroscientific story, our conscious macro-experiences of bound phenomenal objects apprehended by a unitary phenomenal self somehow “arise” instead from patterns of classical, decohered neuronal action potentials synchronously firing over timescales of milliseconds. Yet an answer of “nothing at all” to the question of what it feels like to instantiate a sub-femtosecond neuronal superposition is not a possible response for the nonmaterialist physicalist. For if nonmaterialist physicalism is true, then phenomenal simples are the world’s intrinsic physical properties—the “fire” in the equations of quantum field theory. A fleeting, macroscopic, neuronal superposition is just such a phenomenal simple: it’s not an aggregate or classical ensemble of anything more primitive. Classical glue cannot bind; quantum-coherent glue cannot do anything else; thermally induced decoherence in the CNS explains just how rapidly our fragile minds become unstuck. Thus decoherence can be viewed as a progressive phenomenal unbinding—in other words, effective dephasing is a solution to the phenomenal unbinding problem. The universal wavefunction is not a mind.

The alternative to such a perfect structural match hypothesis is equally stark. Unless we abandon the conceptual framework of physicalism, then mere synchronous[23] neuronal firings cannot phenomenally bind purely classical neurons or neuronal “mind-dust” into cross-modally matched phenomenal objects, nor a spatiotemporally unitary perceptual field, nor a transiently unitary phenomenal self. Mere synchronous neuronal firings cannot bind any more than, say, synchronous activation and reciprocal, electromagnetic communications could phenomenally bind a community of skull-bound American minds. It is not that we can disprove Eric Schwitzgebel’s claim that “if materialism is true, the United States is probably conscious.”[24] Rather, the emergence of such a unitary pancontinental subject of experience would be unexplained and inexplicable—a miracle in all but name. Such spooky “strong” ontological emergence would violate physicalism in a most spectacular way. By the same token, if our 86 billion-odd neurons always behaved as essentially classical systems, as they do in a dreamless sleep or coma, then the emergence of a unitary pancerebral subject of experience, a “person”, would be inexplicable as well. Such spooky strong emergence would violate physicalism too.

Of course, the difference between the USA and the mind-brain is that—unlike a hypothetical, pancontinental subject of experience—it’s hard to treat the existence of one’s own conscious mind as simply a conjecture. Rather the existence of one’s bound, conscious mind is what needs to be explained—unless you happen to be a philosophical zombie.

That said, eliminative materialists like Daniel Dennett[25] are right to recognise that qualia (raw phenomenal experiences) are impossible within a materialist ontology. More particularly, eliminative materialists are right to recognise that the existence of qualia in the brain—as understood by classical materialistic neuroscience—is a physical impossibility, whether the existence of phenomenal symphonies, chairs, tables, mountains or the whole panoply of lived experience. Yet this alleged impossibility derives from a combination of our classical misrepresentations of the mind-brain; our temporally coarse-grained observations of other central nervous systems; and our quasi-hardwired perceptual naive realism with the crude, materialist ontology it spawns. We are not entitled to infer that humans must be insentient zombies on the grounds that our materialist ontology can find no naturalistic place for sentience. The eliminative materialist who forgoes anaesthesia before surgery has yet to be born.

An obvious counterargument to such a (presently hypothetical) perfect fine-grained match between the phenomenology of our minds and the physical structure of the CNS is that we perceive our surroundings with a time lag of scores of milliseconds. Such a time lag is orders of magnitude too long for ultrarapidly thermally “destroyed” (i.e., lost to the environment in a thermodynamically irreversible way) quantum-coherent neuronal superpositions to be computationally relevant to perception.

This objection presupposes an untenable perceptual naive realism in which we directly “see” the mind-independent world—the same misconceived perceptual naive realism according to which a neurosurgeon directly “sees” the cheesy, wet nervous tissue constituting the mind-brain of an anaesthetised patient lying on his operating table prior to surgery.

Such perceptual naive realism may be compared with Bertrand Russell’s apt reminder that no one—not even a neurosurgeon in the operating theatre—ever “sees” anything but the inside of their own head. On our contrasting world-simulation model, the role of the local, mind-independent environment is essentially to select quantum-coherent superpositions of the awake mind/brain via optic (and other) nerve inputs with an evolutionarily minimised time lag.

If Tegmark’s calculations[26]—as distinct from his conclusions—are approximately correct, then our world-simulations must run at anything from around 10^13 quantum-coherent neuronal “frames” per second up to a frame rate of up to 1020+ quantum-coherent neuronal “frames” per second. The fitness-relevant environmental patterns that they track in waking states lag behind their neural counterparts by a hundred or more milliseconds. In that sense, we always “live in the past”, but our waking world-simulations run in near-enough to real time for organic robots to behave flexibly and adaptively in an inhospitable environment.

A suggestive analogy here might be the persistence of vision undergone by organic minds watching a movie at 24 frames per second. Each composite frame of the movie can be rich, diverse and multifaceted despite the lack of perceptible individuality or any “gappiness” to our minds when the frame-sequence is run. The film would seem the same if it were a notional 10^15 x 24-frames-per-second movie. However, the inner-theatre metaphor of mind can also mislead. This is because such a metaphor seems to generate an infinite regress of homunculi. How is the inner spectator supposed to view the internal scene if not by means of another inner spectator in turn, and so forth. In reality, our minds partly instantiate the virtual world-simulations they run. All analogies break down somewhere. The Cartesian theatre is no exception. Note that the phenomenal unity of perception at issue here is what philosophers call “synchronic” unity. No claim is being made about “diachronic” unity, the fictitious temporal persistence of an enduring metaphysical ego. Such enduring personal identity is fundamental to our conceptual scheme. Yet persisting selves are impossible to reconcile with a physicalistic world-picture, not least with the rapid, metabolic turnover of one’s constituents—or with the existence of one’s 10^100 near-identical namesakes that post-Everett quantum mechanics implies partially decohered (“split”) since the start of this sentence.[27] For expository convenience, the narrative fiction of enduring personal identity will here be retained. In principle, however, each ultrathin “slice” or quantum-coherent frame of episodic self could be labelled with its own numerical subscript.

A more robust a priori objection to quantum-mind hypotheses of phenomenal binding might run as follows: No, says the traditional materialist and coarse-grained functionalist, we don’t yet understand how consciousness arises from patterns of neuronal firings in the brain. But as reductive physicalists, we shouldn’t be surprised at the structural mismatch between the phenomenology of bound phenomenal objects and the microstructure of the brain any more than we should be surprised at the structural mismatch between video game characters and the program code running on the classical computer processor that executes them. There is no need to invoke quantum “woo” when well-understood classical physics and learning algorithms work just fine. Indeed, the same point could be made of a massively classical parallel, “sub-symbolic” connectionist[28] information-processing system that lacks the transparent and projectable[29] representations of a classical, serial computer. Connectionist systems are sometimes called “neural networks” in recognition of their closer gross architectural resemblance to the mind-brain than a programmable serial digital computer.

Unfortunately, this argument doesn’t work either. For sure, when speaking colloquially as though perceptual direct realism were true, we can talk about seeing visually bound video-game characters battling their way across a computer monitor. And yes, these classical computer-created videogame characters are generated via well-understood, classical computations. No need for quantum woo here. However, the manifest phenomenal binding is done entirely by—and is entirely internal to—the sentient organic minds playing the video game: it’s internal to the phenomenal world-simulations of the game’s players. Such binding is not a property of anything internal to the mind-independent computer display unit. Video-game characters lack true ontological integrity; they are not unitary subjects of experience running phenomenally bound world-simulations of their own. All that exists in the mind-independent world are thousands (or millions) of effectively discrete pixels on a monitor screen. Whether our fundamental ontology of the natural world is materialist, panpsychist or idealist in character, these effectively classical pixels do not generate phenomenally unitary subjects of experience that sentient minds engage in combat. Rather, their programmed patterns are part of the distal causal chain that culminates in the minds of organic sentients as video-game characters, i.e., their patterns on a monitor causally covary with the phenomenal game avatars populating the phenomenal gadgets of our phenomenal world-simulations. Effectively, there are no bound phenomena in our personal computers to be matched or mismatched.

In fairness, the insentience of digital zombies has been challenged (cf. “This guy thinks killing video game characters is immoral”[30]). Quantum mind-binding theory vindicates sceptical common sense here.

So what would an exact structural match between bound experiential objects and the superposition of state vectors of neuronal edge-, motion- and colour-detectors etc. over ultra-Tegmarkian timeframes entail? In “Are Perceptual Fields Quantum Fields?”[31] Brian Flanagan aptly cites Paul Dirac’s Principles of Quantum Mechanics (1967):

When a state is formed by the superposition of two other states, it will have properties that are in some vague way intermediate between those of the original states and that approach more or less closely to those of either of them according to the greater or less “weight” attached to this state in the superposition process. The new state is completely defined by the two original states when their relative weights in the superposition process are known, together with a certain phase difference, the exact meaning of weights and phases being provided in the general case by the mathematical theory.

Of course, Dirac wasn’t assuming quantum-coherent superpositions of qualia-fields, but rather quantum-coherent superpositions of fields of nonphenomenal we-know-not-what. Moreover, Dirac was writing about quantum microphysics, not short-lived superpositions of mesoscopic and macroscopic phenomenal objects in warm, wet organic brains. Yet what if our traditional insistence on a nonphenomenal metaphysical essence to our field-theoretic ontology is dropped? Quantum field theory is no more inherently about fields of insentience than Maxwell’s theory of electromagnetism is inherently about the properties of luminiferous aether. (Cf. Heinrich Hertz’s terse observation, “Maxwell’s theory is Maxwell’s equations.”) Neither theoretical physics nor the phenomenology of mind give any comfort to the idea that the superposition principle really breaks down in the CNS.

6. CAN PHYSICALISM BE SAVED?

Picoseconds are of an unimaginably, mind-wrenchingly long duration compared to the fundamental Planck scale of around 10-43 seconds—over thirty orders of magnitude more protracted. Femtosecond, attosecond and even pancerebral, zeptosecond rates of environment-induced decoherence are still staggeringly long-drawn-out durations once we leave the everyday intuitions of folk chronology behind. Nonetheless, most neuroscientists would confidently predict that invoking an exact phenomenal-physical structural match at Tegmarkian temporal resolutions to solve the phenomenal binding problem is not just (potentially) falsifiable but false. All we will discover via interferometry in the warm and wet CNS at such timescales is an uninteresting, functionally irrelevant and effectively random thermally induced “noise”—not the structural shadows of bound phenomenal objects. After all, picoseconds are seven or eight orders of magnitude shorter than the widely accepted timeframe over which electrochemical, neuronal firings cause consciousness to “emerge”, inexplicably, in our central neural networks. And pancerebral quantum-coherent neuronal superpositions can credibly subsist only for sub-attosecond timeframes before the well-defined phase relations between the components of the superposition are lost, i.e., extended to the extraneuronal environment in a thermodynamically irreversible fashion.

Again, perhaps orthodoxy is correct. At issue here is a scientifically falsifiable conjecture, not a purely “philosophical” claim. Yet if folk neurochronology is vindicated, then the prospects for physicalism and the ontological unity of science are bleak or even nonexistent. If folk neurochronology is vindicated, something ontologically irreducible is present in the world and missing from the formalism of physics. The spectre of “strong” emergence rears its head—or, worse, dualism, whether avowedly “naturalistic” or otherwise. True, materialists and epiphenomenalists do not face the binding problem in quite the same way as the physicalistic idealist. Instead, bound phenomenal objects can simply “emerge” in the brain, like Athena sprung fully formed from the head of Zeus.

The ontological floodgates are opened.

7. WHAT IS IT LIKE TO BE SCHRÖDINGER’S CAT?

So let us provisionally suppose, in defiance of orthodox neuroscience but in conformity with the formalism of unmodified quantum physics, that our prediction of a perfect physical-phenomenal, structural match in the CNS turns out to be correct, confounding Chalmers and thereby lending experimental weight to an idealist ontology of monistic physicalism. Rather than embrace epiphenomenalism or Chalmersian dualism, we may on this story transpose the entire mathematical machinery of modern physics to describe an idealist ontology. According to this proposal, sentient beings are wavefunctions in configuration space—fields of phenomenally bound, subjective experience whose exact textures are expressed by the values of two numbers, the amplitude and the phase, specified at every point in the universe’s configuration space: physicalistic idealism. Every mathematical property of the wavefunction (except the overall phase) corresponds to some subjective property of the physical world. Suspending disbelief, what would be the payoff if this conjecture were true? Let us return to the criteria that must be satisfied by a scientifically adequate theory of conscious mind.

1) Why consciousness exists at all.

This question is perhaps best recast as “Why is there something rather nothing?” or, more poetically, Hawking’s “What is it that breathes fire into the equations and makes a universe for them to describe?” Mysteries should not be multiplied beyond necessity. By positing a nonphenomenal “fire” in the equations and then hand-waving on how such nonphenomenal stuff might notionally be transmuted into something phenomenal yet still (somehow) material, avowed materialists build a speculative, dualistic ontology into their conceptual framework right from the outset. Compare the Catholic doctrine of transubstantiation. The bread and wine used in the sacrament of the Eucharist literally become the body and blood of Christ while all of their features accessible to the senses remain unchanged. In both cases, we confront a mystery “that surpasses all understanding”.

There is one fundamental mystery. Why does anything exist at all?
When investigating why the enigmatic “fire” of physical consciousness exists, perhaps the fundamental qualia-fields of a quantum vacuum, perhaps we might explore some kind of zero ontology as the ultimate, logico-physical principle underlying reality with the field values of the world’s hypothetical fundamental microqualia “cancelling out” to zero in a multiverse of net zero information. Within this research program, Tegmark’s “Does the universe in fact contain almost no information?”[32] might have considered whether the quantum Library of Babel—our Everettian multiverse?—contains any information. For in the absence of a preferred basis, the state vector of Everett’s multiverse doesn’t per se contain any information.[33] If so, “a theory that explains everything explains nothing” isn’t the witty but shallow quip one might assume. No canonically preferred bases of Hilbert space could exist without violating a zero ontology. The mathematical structure of quantum theory allows indefinitely many ways (conventionally, infinitely many ways) to decompose the quantum state of the multiverse into a superposition of orthogonal states. This leads to another question. Is Eugene Wigner’s observation of the “Unreasonable Effectiveness of Mathematics in the Natural Sciences”[34] explained by the need to conserve an informationless zero ontology—the conservation law that forbids substantive existence? Are the superposition principle and a zero ontology one and the same?
Such difficult questions are beyond the scope of this paper. Proposing that the superposition principle of QM explains both the properties of our minds and why anything exists at all sounds preposterous. But the idea that we may understand either mind or quantum theory without understanding why anything at all exists may be naive.

2) How consciousness has the causal power to allow intelligent agents to investigate its nature.

According to idealistic physicalism, a sentient agent really does remove its hand from the flame because the burning sensation feels agonisingly hot. Unusually, common sense is actually correct. For sure, in many contexts, for example all programs executed on a classical digital computer, the particular microtextures of experience constitutive of its phenomenally unbound physical circuitry are logically and computationally irrelevant to the execution of a program. The particular microtextures of experience are mere implementation details. But if physicalistic idealism is true, then strictly speaking all consciousness, and only consciousness, exerts causal power, effectively mediated by what we normally recognise as the four forces of nature, or perhaps, ultimately, the vibration modes of higher-dimensional branes of M-theory. Only the physical has causal efficacy; and consciousness discloses the intrinsic nature of the physical.

Without such causal power, not merely would intelligent agents be unable to investigate consciousness: we wouldn’t have grounds for alluding to the existence of consciousness in the first instance. By way of distinction, epiphenomenalists want to claim, presumably, that they have rational grounds for believing epiphenomenalism is true—that epiphenomena really are causally impotent. Yet it is unfathomable, to say the least, how such grounds can be stated without implicitly acknowledging a causal role for the epiphenomena that the claim repudiates.

Likewise, on pain of inconsistency, the materialist can’t simultaneously assert—as Hawking does most famously in A Brief History of Time—that we have no idea of the character of the “fire” in the equations and yet also dispute that its essence could be phenomenal experience. No doubt “fire” consisting of a nonphenomenal je ne sais quoi is a plausible speculation. Yet the claim itself borders on the metaphysical. How does the materialist propose to test his conjecture?

We are also now in a position to answer a commonly posed thought-experiment. Materialists wrestling with their Hard Problem of consciousness sometimes wonder why we don’t live in a world physically type-identical to our world but populated instead by insentient zombies. Yet if consciousness discloses the intrinsic nature of the physical, and if quantum-coherent phenomenal binding is the hallmark of mind, then a nonsentient world physically type-identical to our world is logically impossible. A possible world can’t simultaneously be physically identical and physically nonidentical to our world.

To spike some guns, physicalistic idealism isn’t a license for free will, human dignity, animism, New Age mysticism, quantum healing, a reconnection with the timeless wisdom of the ancients, or anything warm and fuzzy. Nor does it invoke quantum mechanical “hidden variables”. Nor does it claim that “consciousness collapses the wavefunction.” Nor is it a variant of Berkeleyan idealism or the philosophical speculations of the German idealists, though Kant’s “transcendental unity of apperception” foreshadowed the global-binding problem. Nor is it a sceptical hypothesis. Thus the physicalistic idealist believes that the mind-independent world existed long before the evolution of bound phenomenal minds in biological organisms. Across the cosmos, the mathematical straitjacket of relativistic quantum field theory is as tight as ever. Physics—or, rather, tomorrow’s ideal physics beyond the energy range of the Standard Model—is causally closed and complete. But within this naturalistic categorical framework, physics is not assumed to be about some essentially nonphenomenal metaphysical “stuff” or unknowable “fire” beyond the reach of scientific investigation. In more Kantian terminology, consciousness is here conjectured to be the noumenal physical essence of the world, the Ding an sich (“thing-in-itself”) that Kant assumed would forever be unknown and unknowable. Physicalistic idealism turns Kant on his head. The noumenal world is all one can ever know, or at least a tiny part of it, other than by inference and conjecture. And the phenomenology of even this sliver of direct knowledge is theoretically contaminated; Wilfrid Sellars called the realm of pure, non-inferential experience the “myth of the given”.[35]

3) How consciousness can be phenomenally bound in seemingly classical forbidden ways.

Physicalistic idealism is not animism or vitalism. Its advocates no more believe that a rock is a unified subject of experience than does, say, an eliminative materialist like Dennett. In common with every other naturalistic theory, the physicalistic idealist still has a lot of work to do in order to show how a bunch of ostensibly discrete quasi-classical nerve cells (or “mind-dust”) can generate bound phenomenal objects or a unitary, phenomenal self.

Two key questions arise in tackling the classically insoluble binding problem/combination problem:

a) Is macroscopic quantum coherence in the CNS a physically real phenomenon?
b) If so, is the phenomenon long-lived enough to do any computationally and/or experientially useful work, as distinct from being functionally incidental neuronal “noise”?

If quantum mechanics is complete, then the answer to the first question is “yes”, albeit over what are, intuitively, vanishingly short durations. However, the existence of macroscopic quantum coherence in the CNS does not, of itself, make the mind-brain a quantum computer any more than the quantum-mechanical properties of silicon semiconductors make one’s desktop PC a quantum computer. One’s phenomenal mind and its world-simulation functions as a quantum computer only if what we—naively and classically—describe as the synchronous firings of classically parallel neuronal cellular feature-detectors (edges, colours, shapes, motions, vertices, etc.) briefly support a unitary experiential object: the wavefunction of an intelligent, information-processing experiential agent.

This absence of individual neuronal identity in what would otherwise be—as in a dreamless sleep—effectively classical neurons/mind-dust presumably occurs with an ultrafast “refresh rate”—where “ultrafast” alludes to our everyday chronological intuitions rather than Planck-scale physics. Within any given sequence of mental life, dropped and mangled frames aren’t noticed as such because they aren’t explicitly represented in other individual frames. On this story, the molecular structures of our explicit “memories” consolidate only on a much coarser-grained timescale—ranging from hundreds of milliseconds to minutes, hours, days and in extreme cases, a hundred years or more. Quantum mind-binding isn’t a replacement for connectionist neuroscience or its temporally coarse-grained learning algorithms; rather, it’s the bedrock.

So what is conscious? Conversely, what’s a micro-experiential zombie?

On this touchstone of sentience—i.e., quantum coherence as the physical signature of phenomenal binding—macroscopic quantum fluids; SQUIDs (Superconducting Quantum Interference Devices); organic mind-brains while not dephased in a coma or dreamless sleep; and perhaps futuristic nonbiological quantum computers are unitary experiential subjects.

Conversely, if effective classicality is the hallmark of the zombie, then serial digital computers, classically parallel connectionist systems, classical dynamical systems, rocks and mountains, the population of the USA and cellulose-cell-wall-bound plants etc. are not subjects of experience. Rather they are just decohered aggregates, in effect composed of phenomenal simples.

Perhaps contrast neuroscientist Giulio Tononi’s integrated information theory,[36] in which consciousness is a function of informational complexity.

If the quantum mind-binding hypothesis sketched here is true, the largest quantum supercomputer in the world currently belongs to the sperm whale: a mind around five times heavier than its human counterpart. The human cerebral cortex is 2–4 mm thick; but actually we have to take a four-dimensional approach, or more ambitiously, a finite[37] dimensional Hilbert-space approach, and imagine our minds as approximately 10^100 quasi-classical Everett branches “jostling” each other before becoming irreversibly “split”, i.e., effectively decohering and losing their well-defined phase coherence to the extracerebral environment. Intuitive plausibility is not the hallmark of a scientifically adequate theory of consciousness. Experiment, not philosophy or armchair physics, is the key.

4) Why and how consciousness manifests its diverse textures—ranging from phenomenal colours, sounds, tastes and smells, pains and pleasures, the experience of introspecting a thought-episode, feeling pangs of jealousy, hearing an orchestra play, admiring a sunset, to finding a joke amusing.

If idealistic physicalism is true, then the solutions to the field-theoretic equations of physics mathematically encode the textures and interdependencies of micro-experiences. The amplitude and phase of one’s wavefunction yield the exact values of all one’s experiences. On this conjecture, there are no hidden parameters or missing variables that the existing quantum-mechanical formalism omits. Quantum mechanics is indeed closed and complete—or more strictly, it will be closed and complete when it subsumes gravity. Hence the spectre of causal overdetermination, epiphenomenalism or even dualism in theory of mind is lifted. Another kind of dualism, the spurious divide between the classical macroworld and the quantum microworld, evaporates too. The appearance of phenomenally bound classical objects in a classical world is a derived quantum effect, not a brute unexplained fact that a classical materialist ontology can’t accommodate.

Finally, 5), any satisfactory scientific theory of consciousness should also offer predictions that are both novel and experimentally falsifiable.

Untestable claims may be scientific if they are entailed by a conjecture that generates novel, precise and nontrivial predictions that can be empirically tested. Physicalistic idealism is radically conservative insofar as it does not propose any modification or supplementation of the existing, realistically interpreted, quantum-field-theoretic formalism. Contra Penrose and Hameroff’s “orchestrated objective reduction” (Orch-OR[38]) model, for example, there is no evidence that the unitary dynamics of standard quantum mechanics breaks down in the central nervous system or anywhere else. Yet—without proposing any new physical law(s)—physicalistic idealism also predicts the existence of an empirically investigable phenomenon that few researchers now credit. Namely, our everyday classical world-simulations are underpinned at sub-femtosecond timescales by macroscopic quantum-coherent physical states of the CNS. One’s phenomenally bound, quasi-classical virtual world is what a natural quantum computer feels like from the inside, so to speak. Familiar classical worlds of phenomenally bound objects obeying Newtonian laws of motion and gravity within one’s perceptual field are an entirely quantum-mechanical phenomenon. Classical phenomenal macroworlds would be impossible without successive neuronal superpositions of distributed feature-processors to underpin their existence.

What Tegmark treats as a reductio ad absurdum of quantum mind is treated instead as a falsifiable, empirical prediction. Nature got there first and natural selection got to work.

Of course, if a classically minded critic is convinced a priori that macroscopic quantum-coherent neuronal superpositions of sub-femtosecond duration are of no more computational or phenomenal relevance to explaining consciousness than, say, the detection of evanescent quantum superpositions of the pawns and the queen during a game of chess, or random thermal noise in a classical CPU executing a program on one’s PC (etc.), then such a critic will not waste time independently setting up the exceedingly delicate experiments necessary to detect the missing physical signature of phenomenal binding. They might simply say, noise is noise. Collisional decoherence, dephasing due to inertial forces and vibrations and, above all, thermal decoherence are all formidable obstacles to detecting the indirect signature of neuronal superpositions even with the tools of next-generation interferometry.

Such a cavalier dismissal of the only way to save physicalism and the ontological unity of science may prove premature. We will now set out the protocol for an experiment to test the naively absurd conjecture that binding-by-synchrony is really binding-by-superposition.

8. SCHRÖDINGER’S NEURONS:
THE EXPERIMENTAL PROTOCOL

In vivo experiments using live human subjects or cats are impossible for the foreseeable future. However, cultured in vitro neuronal networks should suffice. First, “train up” a multilayer neuronal network with a suitable input-output device to recognise a variety of externally presented inputs. Then, identify in turn the distributed neuronal feature-processors implicated in diverse object recognition on a standard, classically parallel connectionist account, i.e., “local” phenomenal binding. Routine neural scanning can pick out what we would naively describe as the synchronously activated distributed neuronal feature-processors elicited by any given stimulus, i.e., textbook connectionist neuroscience but using real neurons rather than tendentiously named “artificial neural networks” and their statistical learning algorithms.

Next comes the fiendishly hard part—feasible in principle, but an experimental challenge still beyond the reach of molecular matter-wave interferometry. Instead of detecting the fleeting nonclassical interference patterns of “nonsense” neuronal superpositions, the conjecture predicts that we’ll discover the interference signature of sub-femtosecond macro-superpositions that robustly implicate exactly the same neuronal feature-processors of the synchronously activated neurons that the classical neuroscience story reports are activated in the trained-up neuronal network when object-recognition occurs. On any classical account of mind, such an experimental outcome, i.e., a perfect structural match, is either physically impossible or vanishingly improbable.

The best-known physically demonstrable manifestation of quantum-coherent superpositions is the interference peaks from an electron wave in a double-slit experiment.[39] Currently, matter-wave interferometry can detect “mesoscopic” superpositions of fullerenes[40] in the guise of observable de Broglie wave interference of C_60 and C_70 molecules following passage through a diffraction grating. Experimental superpositions of viruses[41] and tardigrades (“water bears”) are planned. Detecting the interference patterns of neuronal superpositions with their hugely more numerous excited internal degrees of freedom will be much more challenging because—unlike fullerenes or viruses—functioning neuronal networks can’t be steeply cooled down to mitigate the effects of thermally induced decoherence. In neuronal networks, ion-ion scattering, ion-water collisions and long-range Coulomb interactions from nearby ions all contribute to rapid decoherence times; but thermally induced decoherence is even harder experimentally to control than collisional decoherence.[42]

However, we may assume tomorrow’s experimentalists will rise to the challenge. Let’s review the possible outcomes. What will experiments detect when molecular matter-wave interferometry can probe the sub-femtosecond timescales over which theory predicts neuronal superpositions should exist?

1) a) no interference effects, or at least some collapse-like deviation from the unitary Schrödinger dynamics, i.e., the superposition principle breaks down in artificial neuronal networks and thus presumably in the CNS. This negative outcome is what Penrose and Hameroff;[43] Ghirardi, Rimini and Weber (GRW);[44] and other dynamical collapse theorists would predict.

Or,

b) the telltale nonclassical interference signature that the unitary dynamics predicts.

If b) is the case, then will the sub-femtosecond neuronal superpositions detected be:

2) a) functionally irrelevant psychotic noise, of no more relevance to the orderly phenomenology of our bound phenomenal minds than, say, fleeting sub-femtosecond superpositions of miscellaneous pawns to the gameplay in a chess match? The Chalmersian “structural mismatch” claim would thus be vindicated.

Or, b), a perfect structural match that implicates all and only the synchronously firing feature-mediating neurons that orthodox neuroscience reveals are activated when individual phenomenally bound objects are perceived?

Our femto-mind binding conjecture predicts (b) in both cases.

Some comments are in order here. First, a good experiment should be “clean” and conceptually simple—its outcome decisive to sceptics and hostile critics, not just to the satisfaction of the conjecture’s proponents. No scope should exist for fudging, ad hoc escape clauses or adding epicycles. By this criterion, the experiment outlined here is decisive. A critic of quantum mind will be unfazed by such professions of epistemic virtue: by analogy, building a perpetual-motion machine would be a clean, elegant and definitive refutation of the second law of thermodynamics, too; it’s not going to happen. Less fancifully, an example of an “unclean” experiment is the discovery of quantum vibrations in microtubules inside brain neurons as a test of the Hameroff-Penrose Orch-OR theory of mind. Their discovery, though intriguing, will not persuade critics that modified quantum theory makes Gödel-unprovable results provable by human mathematicians.

Second, strictly speaking, it’s not necessary to assume that the superposition principle of QM is universal. Maybe spontaneous localisation kicks in at scales larger than the mesoscopic and modestly macroscopic dimensions of organic mind-brains. Such a breakdown would be physically unmotivated. No departure from the Schrödinger dynamics has ever been detected. But the experimental demonstration of neuronal superpositions won’t rule it out.

Third, we have avoided fascinating but incidental speculation about, e.g., the properties of liquid water as a unique quantum fluid, dipoles forming superposed resonance rings in helical pathways in microtubule lattices,[45] and so forth. The existence of neuronal superpositions implicating previously naively identified phenomenal feature-mediating nerve cells is a generic prediction of any conjecture that invokes coherent superpositions of neuronal feature-processors as the explanation of phenomenal binding. The conjecture—and its confirmation or falsification via matter-wave interferometry—is insensitive to the details of its molecular implementation. Darwin needed Mendel. The ubiquitous selection pressure of Zurek’s “quantum Darwinism” applied to the CNS awaits Mendel’s counterpart.

Fourth, demonstration of this exceedingly subtle physical interference effect—if experimentally confirmed—is not remotely the only reason for believing that organic minds are quantum computers, or that experience discloses the intrinsic nature of the physical. The most striking reason lies in front of our virtual eyes and under our virtual noses, so to speak. But the existence of phenomenal binding is a retrodiction, “old evidence”, not a novel prediction. Any claim that armchair philosophising can establish that the mind is a quantum computer will be given short shrift by critics—even if the claim happens to be true. This in vitro interferometry experiment is pitched at quantum mind’s most implacable foes.

9. FEMTO-MIND MEETS QUANTUM DARWINISM

I still recall vividly the shock I experienced on first encountering this multiworld concept. The idea of 10^100 slightly imperfect copies of oneself all constantly splitting into further copies, which ultimately become unrecognizable, is not easy to reconcile with common sense. Here is schizophrenia with a vengeance.

Bryce DeWitt

If DeWitt’s notorious misreading of Everett[46] were true, then we would be (at most) micro-experiential zombies in all life-supporting branches of the universal wavefunction. Unified subjects of experience would be impossible. We’d know nothing of one branch, let alone the googols of others. However, DeWitt was mistaken. There is only one world—the multiverse—and its decohering branches never completely separate. DeWitt’s remark nonetheless offers a clue to meeting what might seem a decisive objection to a quantum-mind account of phenomenal binding. How could selection pressure operate over a timescale of femtoseconds, attoseconds or less? The answer is that whereas selection pressure can’t act on proliferating worlds, it can act on proliferating, decohering world-simulations. In order to understand our minds and the world-simulations they run, Zurek’s “quantum Darwinism”[47] must be applied to the CNS. Here we have a Darwinian selection-mechanism of unimaginable power: ubiquitous, unremitting and temporally fine-grained. Who will play Mendel to Zurek’s Darwin is unknown. These cryptic remarks will now be amplified.

How could non-psychotic phenomenal binding of distributed neuronal feature-processors have evolved? The generation by vertebrate minds of cross-modally matched virtual worlds in almost real time is prodigiously computationally powerful and genetically adaptive. Mere patterns of Jamesian “mind-dust” couldn’t act. Connectionist neuroscience describes at a coarse-grained level how individual perceptions are represented by shifting coalitions of resting/firing patterns of membrane-bound neuronal feature-processors using different learning algorithms. Yet if the phenomenology of virtual world-making ultimately depends on sub-femtosecond quantum coherence, then the evolution of nonpsychotic phenomenal binding would naively seem evolutionarily impossible. Decoherence, i.e., the rapid effective loss of ordering of the relative phases of complex amplitudes of neuronal superpositions to the environment, is a powerful, omnipresent and seemingly uncontrollable effect in the warm, wet CNS.

But we needn’t turn to drink or dualism yet. If a femto-mind-binding conjecture is correct, and if the unitary dynamics of QM doesn’t break down in the human mind-brain, then a qualitative answer to the evolutionary enigma of phenomenal binding can be given within the conceptual framework of the “quantum Darwinism” articulated by one of the pioneers of the decoherence program in post-Everett quantum mechanics, Wojciech Zurek. The decoherence program outlines the Darwinian[48] process responsible for the emergence of quasi-classical reality from its quantum substrate within Everett’s multiverse. If a femto-mind–binding conjecture is correct, then an analogous Darwinian process of replication, variations amongst the copies and differential survival of the copies is responsible for the emergence of the quasi-classical phenomenal worlds forming our minds from their quantum substrate in the CNS. Some superpositions are fitter than others. In order for an ecologically credible quantum mind-binding conjecture to be viable, all that is needed for selection pressure to get to work is the slightest heritable predisposition to the tiniest of transmissible resistance to collisional and thermally induced decoherence of non–psychotically bound phenomenal neuronal superpositions in even the humblest of cephalic ganglia. All organisms capable of neuronal world-modelling evolve and adapt to their environment by an iterative process. This iterative process may be treated as an evolutionary algorithm that searches the fitness landscape for the locally and globally bound phenomenal states of mind—quantum-coherent neuronal superpositions—that are best adapted to their local surroundings. Thus a Darwinian process of variation and differential selection of informational superpositions plays out as the fittest phenomenally bound variants are retained and passed on to their offspring.

It’s worth stressing again: contra DeWitt’s colourful quote above, there is only one multiverse; interference effects between Everett branches that have effectively decohered (“split”) never wholly disappear. Within the universal wavefunction, such a Darwinian process hypothetically plays out both between proliferating, sexually reproducing biological organisms and fast-proliferating states of the mind-brain of individual organisms across Everett branches. Thanks to hundreds of millions of years of natural selection, the most dynamically stable, phenomenally bound system–environment correlations are the non–psychotically bound phenomenal objects populating our waking world-simulations. Psychotic binding in maladapted organisms does still occur, comparatively infrequently, but statistically, one’s waking consciousness (as now) is overwhelmingly likely to consist in non–psychotically bound states of an adapted organism, not the Earthly counterpart of a Boltzmann brain. What we’re calling “informational” and “psychotic” binding should be conceived dimensionally rather than categorically. Thus a fleeting quantum-coherent superposition of distributed neuronal feature-processors experienced as, say, a flying purple dragon is psychotic in the context of the ancestral environment of adaptation, whereas fleeting quantum-coherent neuronal superpositions of distributed feature-processors experienced as an approaching lion were potentially hugely fitness-enhancing in the extraneural presence of a hungry predator. But flying purple dragon superpositions are not intrinsically psychotic, any more than the phenomenally bound features of predatory lion superpositions are inherently referential—on pain of a magical theory of reference. Indeed, in some future fantastical techno-utopia—or immersive VR with different laws from basement reality—flying purple robodragon superpositions could be functionally nonpsychotic. They might track patterns in the local mind-independent environment. What counts as sanity is contextual.

For illustrative purposes, an example with somewhat greater ecological validity than neuronal flying purple dragon superpositions might be in order. Imagine a savannah-dwelling herbivore with two disorders of phenomenal binding: both simultanagnosia and cerebral akinetopsia. Not merely can the herbivore’s doubly unbound mind apprehend only a single perceptual object at a time; the object’s progressive motion can’t be perceived. So not merely is just a single member of an approaching pride of hungry lions apprehended within the herbivore’s CNS world-simulation; the hungry carnivore in question just appears successively nearer without perceptibly advancing. Such a neurologically devastating condition might seem a sure-fire recipe for the hapless herbivore becoming lunch. Today, such a grisly fate would be almost inevitable. Yet to survive and genetically propagate, the doubly unbound ancestral herbivore doesn’t need to outrun the approaching lions—merely to run faster than other members of the herd. If his or her conspecifics are capable only of psychotic binding—or if their neurons are merely effectively classical or phase-scrambled neuronal “mind-dust”—then our doubly mentally unbound herbivore actually has an immense selective advantage over every other member of the herd. For even weak and partial nonpsychotic phenomenal binding confers a huge selective advantage over organisms that lack nonpsychotic binding (at anything above chance levels) altogether. Or to use another, evolutionarily more ancient example, imagine a simple organism with a heritable predisposition to apprehend phenomenal patches of darkness and light—as distinct from the heritable predisposition of its conspecifics to instantiate merely discrete, decohered, effectively classical dark or light neuronal “pixels”. This primordial protobinder can functionally distinguish night from day, and safely graze (or filter-feed) rather than burrow to safety as needed in the shadow of a looming predator. Such an adaptation would be powerfully fitness-enhancing. Over evolutionary history, nonpsychotic binders would outcompete psychotic binders, and superbinders would outcompete binders, culminating in the currently supreme superbinder of them all, Homo sapiens.

Note that on this account, Darwinian selection pressure plays out both between proliferating, sexually reproducing organisms across the generations and also between ultrafast-proliferating neuronal superpositions of the CNS. For although (we conjecture) next-generation matter-wave interferometry will robustly detect a perfect structural match between the reported bound phenomenology of our minds and nonpsychotic neuronal superpositions, nonetheless post-Everett QM suggests that fleeting, erratic, nonsensical superpositions really do exist; they are merely of vanishingly rare measure compared to the information-bearing superpositions favoured by natural selection. Thankfully, experimental interferometry rather than speculative philosophising will decide the issue.

10. A MENDELEEV TABLE FOR QUALIA?

If sentient agents are to understand the intrinsic, subjective properties of matter and energy, or to map out what we naively call the “neural correlates of consciousness”, or, most ambitiously, to devise a comprehensive Mendeleev table for qualia, then the diverse subjective textures of consciousness will play an inescapable role in the investigation by the very nature of the task. Intelligent agents will need to re-engineer themselves—genetically, pharmacologically, neurologically—in order to instantiate the subjective physical states in question. We’ll need to become a full-spectrum “super-Mary”,[49] so to speak—investigating state-spaces of consciousness disclosed by configurations of matter and energy that have never before been recruited for any information-processing purpose. Such state-spaces of consciousness are currently beyond the scope of scientific investigation.

By contrast, classical digital zombies cannot explore the nature of sentience; their circuitry wouldn’t understand what they were investigating, let alone be cognisant of its mechanisms. This far-reaching task falls to bound phenomenal minds. A combinatorial explosion of possibilities means that the investigation of the alien state-spaces of consciousness may take millions of years, perhaps billions or more. By contrast, constructing the mathematical formalism of a unified TOE over the next few decades may prove surprisingly easy.

Early in the twenty-first century, we commonly assume that physical scientists research the objective properties of matter and energy. This is true up to a point. If physicalistic idealism is correct, then this commonplace is no more than a half-truth. For the intrinsic, subjective, first-person properties of matter and energy are real, objective and amenable to formal description via the evolution of the universal wavefunction, just as are the third-person relational properties—the properties captured by the formalism of relativistic quantum field theory or its successor. In short: we’ve mastered the right formalism, just assumed the wrong materialistic ontology. Subjective experience and phenomenal binding are a Hard Problem for the classical scientific materialist in the same way that fossils are a Hard Problem for the creationist. In both cases, the anomaly in question demands a major revision of the believer’s conceptual scheme. In both cases, believers are prone to spending their lives in denial.

On the face of it, to pronounce on the nature of what physical science is actually investigating might seem presumptuous for anyone but a professional physicist. Yet we don’t allow the fact that, say, Newton believed he was investigating divine mechanical clockwork, or that he fancied his interpretation of the Book of Daniel his foremost achievement, to impugn his status as the greatest scientist who ever lived. Likewise, it’s no disrespect to the greats of contemporary mathematical or experimental physics to say that we still don’t understand the intrinsic nature of physical reality. Likewise, it’s no disrespect to hardworking neuroscientists to say that we simply don’t understand the mind-brain when its defining feature, consciousness, is physically impossible within the reigning materialist paradigm of science.

In a similar vein, to assert that mathematics investigates patterns of quantity, structure, space and change would seem a commonplace. The claim that maths is really about qualia patterns sounds bizarre. More telling is Bertrand Russell’s jaundiced observation: “Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.” If idealistic physicalism is correct, then mathematics is ultimately about computable patterns of qualia: their quantity, structure and change. Once again, perhaps we’ve mastered the formalism rather than adequately grasped the underlying ontology whose relations it captures.

11. TOWARDS A POST-GALILEAN SCIENCE OF MIND

If a potato or rutabaga can utilize quantum coherence, it’s likely our brains could have figured it out as well.
Jack Tuszynski

A comprehensive account of reality entails an understanding of the first-person and third-person properties of the natural world—and the mathematically formalised interrelationships between them. If the distinction between the first-person and third-person properties of matter and energy were completely clean, as assumed by traditional AI, then the causal capacity of cognitive agents to allude to both the subjective and formal properties of mind would be physically impossible in the first instance. Thus an insentient p-zombie would be physically unable, for example, to refer indexically to this particular self-intimating thought, or to investigate the nature of phenomenal binding, or to explore the nature of the “fire” in the equations that is responsible for the existence of sentient minds for non-zombies to describe. For a notional materialist p-zombie, it isn’t even “all dark inside”.

The necessity of the experimental method in scientific investigation of the third-person properties of matter and energy has been recognised since Galileo. The intellectual achievements of physical science, as traditionally conceived, are widely celebrated. By contrast, experimental investigation of the great majority of intrinsic, first-person properties of matter and energy is stigmatised and even criminalised. States of sentience as different as waking from dreaming consciousness are outlawed. Instead of Nobel laureates, research grants and lavish institutional funding, an empirically driven exploration of the first-person properties of matter and energy plays out mainly within the scientific counterculture. An entire realm of drug-catalysed knowledge is proscribed as somehow cognitively illegitimate.

Human ignorance is unlikely to last indefinitely. If intelligent agents are to understand the natural world, then the methodology pioneered by Alexander and Ann Shulgin in PiHKAL[50] must be integrated with mainstream academic science: an authentically post-Galilean science of physical consciousness.

Does the claim that biological agents—and perhaps mature, nonbiological, quantum computers centuries hence—can solve problems too difficult for a classical system to pose or answer violate the Church-Turing thesis,[51] i.e., that any effective computation can be carried out by a Turing machine? By itself, technically, no. After all, a notional classical digital computer could be programmed to code the chemical base-pairs for the genotypes of biological super-Shulgins whose phenomenally bound minds could then explore the manifold varieties of sentience and map out the psychophysical relationships between them. Yet such a whimsical proposal doesn’t mean that a classical digital computer could itself ever support a unitary full-spectrum (super)intelligence. Nonclassical phenomenal binding is a necessary precondition for full-spectrum general intelligence. For without phenomenal binding, there is no unitary agent who is (un)intelligent in the first instance, let alone a general problem-solver who can systematically investigate the first-person and third-person properties of the physical world.

What is sorely lacking here is a rigorous account of computation that can handle the investigation of myriad state-spaces of qualia as well as the traditional staples of third-person computing. This challenge doesn’t count as a well-defined or even meaningful question within the reigning paradigm of computer science. Sentient organic minds are biological devices that can answer questions beyond those a classical Turing machine can answer, or even pose—not because we are oracles but because, if the conjecture outlined here is experimentally vindicated, we are sentient, phenomenally bound quantum computers. Full-spectrum superintelligence will entail a seamless mastery of both the formal and the subjective properties of mind: the creation of a mature civilisation of super-Shulgins-cum-super-Turings. Recursively self-improving organic robots are poised to modify their own source code[52] and bootstrap our way to full-spectrum superintelligence. How closely posthuman conceptions of the physical resemble anything humans would recognise[53] is an open question.

12. SUMMARY AND PROSPECTS

The Hard Problem of Consciousness Solved; the Explanatory Gap Closed; the Binding Problem Tamed; Zombies Banished; and Physicalism Saved.

Let’s recap. Here are our key assumptions and the weird but experimentally falsifiable prediction that follows. If the prediction fails, then our defence of idealistic physicalism is refuted.

1) Strong emergence is false. Physicalism is true. No “element of reality” is missing from the equations of tomorrow’s physics and their solutions.

2) Consciousness discloses the intrinsic nature of the physical. Therefore, rudimentary consciousness occurs, not just at ultrasmall distance scales, but also at ultrashort timescales. A future Planck-scale unification of quantum gravity will presumably capture the ultimate psychon of Planck-regime consciousness.

3) The unmodified, unsupplemented formalism of post-Everett quantum mechanics is correct. “Hidden variables”, Bohmian mechanics and dynamical collapse theories of wavefunction collapse are false. Thus macroscopic quantum-coherent neuronal superpositions occur in the mind-brain. At sufficiently fine-grained temporal resolutions, the entire mind-brain exists in a single, conscious, quantum-coherent superposition. A succession of ultra-rapidly decohering, virtual world superpositions constitutes biological minds. Internally, world-simulations typically seem classical. Their vehicles, i.e., phenomenally bound organic minds, are irreducibly nonclassical.

4) Direct realism about perception—and the notion that neurosurgeons or experimenters ever directly “observe” anyone else’s decohered classical brain or decohered classical neurons—is false. When notionally “observing” our surroundings, both awake and dreaming organic minds instantiate individual bound perceptual objects (“local” neuronal binding) that populate dynamic world-simulations undergone by a fleetingly unitary phenomenal self (“global” binding). Phenomenal binding is not a classical phenomenon. Instead, phenomenally bound quantum-coherent neuronal superpositions have been recruited by natural selection to generate seemingly mind-independent, ostensibly classical, virtual worlds. When awake, quantum biocomputers generate such pseudoclassical worlds to track fitness-relevant patterns in our local environment. Except in a dreamless sleep or coma, organic mind-brains are not decohered “pixels” of discrete neuronal micro-experiences.

5) a) The retrodiction: we are not zombies. Nor are we quasi-zombies, i.e., patterns of decohered neuronal “mind-dust”. So there is no Hard Problem of consciousness and, in principle, no binding problem either: we’re not micro-experiential zombies. Instead, we are fleetingly unitary phenomenal minds. Empirical evidence that our minds are quantum computers lies in front of our (virtual) eyes.

5) b) The novel, experimentally falsifiable prediction: next-generation interferometry will detect the sub-femtosecond signature of quantum-coherent neuronal superpositions in the mind-brain in the guise of quantum interference effects AND these indirectly detected quantum-coherent neuronal superpositions will robustly implicate all and only the synchronously firing feature-mediating neurons that orthodox neuroscience suggests are activated when individual phenomenally bound objects are perceived by the experimental subject.

Both of these predictions must be experimentally borne out in order to vindicate the quantum mind-binding conjecture outlined here. So if either no neuronal superpositions are detected, i.e., if the unitary evolution of the state vector breaks down in the mind-brain, or if their interference signature is indeed deciphered but also implicates neurons irrelevant to the neuronal feature-mediators of the particular phenomenally bound object(s) that the experimental subject verbally reports seeing, i.e., if the interference effects detected are functionally just molecular “noise”, then our quantum mind conjecture will be falsified. Falsified too would be our attempt to save physicalism.

Experimentally detecting—or definitively failing to detect—the nonclassical interference effects diagnostic of local phenomenal binding in the CNS will be technically less challenging than detecting the predicted transcerebral quantum interference effects diagnostic of global phenomenal binding and hence the unitary phenomenal self of everyday experience. Yet the quantum mind-binding conjecture will—provisionally—be vindicated if the signature of even local neuronal superpositions in their predicted guise are found. By analogy, if a bizarre but nonetheless falsifiable conjecture predicts—as orthodox neuroscience might claim—the equivalent of little green pixies living at the bottom of the garden, and, amazingly, a single little green pixie is unequivocally detected, then we wouldn’t withhold assent to the bizarre conjecture on the grounds that experiment hadn’t yet detected the theorised pixie breeding colony.

Further challenges lie ahead. The mechanisms supporting the succession of differentially robust sub-femtosecond neuronal superpositions that—hypothetically—underpin phenomenal binding must be elucidated at the molecular level. Only at the molecular level can philosophical hand-waving be turned into real, measurable, quantitatively exact, physical science. At much longer timescales of milliseconds and above, the standard coarse-grained story from connectionist neuroscience and dynamical systems theory takes over from the femto-mind regime. Thus, whether we are in a dreamless sleep, dreaming or wide awake, our memories are coarsely encoded in the connectivity, connection weights and the internal architecture of our neurons after our neural networks have been progressively “trained up”. Besides its idealist ontology, the quantum mind-binding conjecture explored here to save physicalism from the spectre of Chalmersian dualism is radically unorthodox only insofar as what mainstream neuroscience reckons is the mere synchronous firing of classical neuronal distributed feature-processors is conjectured instead to be a succession of quantum-coherent neuronal superpositions. Only experiment can corroborate or falsify this hypothesis. If the prediction fails, then our defence of idealistic physicalism is refuted too.

Also, even if non-materialist physicalism is true, the lack of some sort of Rosetta Stone to “read off” the values of qualia—both bound and unbound—from the solutions to the field-theoretic equations of QFT is a huge challenge. Compare a much more straightforward identification. Nowhere in Maxwell’s field equations is light explicitly identified with electromagnetic radiation. But once the value of the constant c was calculated—around 300,000 kilometres per second—then the identity of its value with the known velocity of light made the identification inevitable. In other words, no “element of reality” was missing from Maxwell’s formalism, or, more strictly, from its subsequent quantum electrodynamic generalisation. Likewise, if idealistic physicalism is true, no “element of reality” is missing from the formalism of relativistic quantum field theory or its currently speculative successor. However, in contrast to the ease of identification of light with visible frequencies of electromagnetic radiation, the conjecture that the solutions to the equations of QFT yield the precise values of all and only physically possible experiences amounts to both a mathematical straitjacket and a veritable Pandora’s Box. For the only way cognitively to grasp the values of the diverse subjective properties of the physical fields of experience that the solutions to the formalism encode is personally to instantiate bound neuronal superpositions of these subjective properties. Even after extensive psychotropic and eventually neurogenetic experimentation, myriad forms of consciousness will presumably be forever inaccessible to rational mind—though equally, many physical systems that today we might naively imagine could in future be unitary subjects of experience, notably ultrapowerful classical digital computers or nonbiological classical connectionist systems, will always be effectively insentient.

Whether our conscious minds are essentially classically parallel connectionist systems, or quantum supercomputers as conjectured here, another enigma remains. The late-evolutionary neurological mechanism by which a massively parallel, biological neurocomputer generates a virtual classical machine—the slow serial stream of one’s logico-linguistic thinking though which this paper is written and read—is unknown. We do know of crude methods to disrupt our stream of logico-linguistic thought-processing. For example, taking LSD induces the “flooding” phenomenon that disrupts serial thought, whereas low-dose psychostimulants tend modestly to enhance logico-linguistic thought. Yet that is as far as it goes. Whatever the nature of this virtual seriality-generating mechanism in the CNS, we can sketch out an evolutionary chronology of information-processing systems. An irreducibly quantum multiverse first generated information-bearing self-replicators—biological life—which manufactured quantum supercomputers in the form of central nervous systems, one species of which spawned the serial, logico-linguistic virtual machines currently unique to human minds. These serial virtual machines conceived and created classical digital computers, then classically parallel artificial connectionist systems, and finally—though here we run a little ahead of our story—artificial, nonbiological quantum computers. The long-term interplay of these multiple architectures is hard to foresee with any confidence, but the destiny of sentient life in the cosmos most probably lies in full-spectrum superintelligence.[54]

REFERENCES

1Einstein, A., Podolsky, B., Rosen, N. (15 May 1935). Can Quantum-Mechanical Description of Physical Reality Be Considered Complete? Physical Review, 47:10 , 777–780.

2Weinberg, S. (1995). The Quantum Theory of Fields (Vols. 1–3). Cambridge: Cambridge University Press.

3Levine, J. (1983). Materialism and qualia: the explanatory gap. Pacific Philosophical Quarterly, 64, 354–361.

4Chalmers, D. (1995). Facing Up to the Problem of Consciousness. Journal of Consciousness Studies 2:3, 200–219.

5Kant, I. (1965). Critique of Pure Reason (N. K. Smith, Trans.). New York: St. Martin’s Press. (Original work published 1781)

6Schopenhauer, A. (1995). The World as Will and Idea (M. Berman, Trans.). London: J. J. Dent. (Original work published 1819.)

7Russell, B. (1921). The analysis of mind. London: G. Allen & Unwin.

8Maxwell, G., 1976, Scientific Results and the Mind-Brain Issue: Some Afterthoughts. In Consciousness and the Brain (G. Globus et al., Eds.). New York, Plenum Press, 329–358.

9Lockwood, M. (1989). Mind, brain, and the quantum: The compound “I”. Oxford: Blackwell.

10Strawson, G. (2006). Consciousness and its place in nature: Does physicalism entail panpsychism? (A. Freeman, Ed.). Exeter, UK: Imprint Academic.

11Hawking, S. (1988). A Brief History of Time: From the Big Bang to Black Holes. Toronto: Bantam Books.

12Everettian QM is simply quantum mechanics minus the collapse postulate: there is no dynamical principle in nature beyond the continuous, linear, unitary and deterministic evolution of the universal wavefunction. Or in John Baez’s memorable acronym, "Get CLUED up." However, physicists only began to understand the emergence of quasi-classical macroscopic “branches” describable by an approximation of classical Newtonian physics with the growth of the decoherence program pioneered by H. Dieter Zeh and Wojciech Zurek. Today probably most physicists would accept that decoherence solves the measurement problem for all practical purposes. Yet on the face of it, decoherence cannot by itself why single experimental observations have definite outcomes: the notorious “collapse of the wavefunction”. Only individual particles, not waves, are ever detected on a screen, with the probability of detection being the square of the amplitude of the wave, i.e., the Born Rule. The nonclassical interference pattern revealed by a double-slit experiment becomes apparent only via the varying density of these individual particle hits on the screen. So what explains the apparent nonunitary transformation of the state vector at the time of measurement into a single definite state? Why does the superposition principle apparently break down? The answer of this paper is that seeing a definite live cat or dead cat, or seeing a definite pointer reading, or seeing a particle hit on a screen exemplifies (sic) the superposition principle. There are no definite outcomes. Instead, there are superpositions of distributed neuronal feature-processors co-opted via selection pressure to play the functional role of phenomenally representing definite outcomes. Only the superposition principle allows what would otherwise be the pixels of experience of discrete neuronal feature-processors (“mind dust”) to be experienced as a definite classical pointer reading, or a definite classical cat, or a definite classical screen (etc.) in one’s world-simulation. By contrast, tough-minded positivist talk of “observers”, “observations” and “measurements” presupposes the theoretical baggage of an untenable perceptual naive realism. On the alternative “Schrödinger’s neurons” conjecture canvassed here, one’s entire classical macroscopic world-simulation consists of individual quantum coherent states, despite the insanely short sub-femtosecond duration of individual neuronal superpositions. Note that what is being conjectured here isn’t some exotic new principle of physics, but rather the significance to consciousness of what most physicists (and neuroscientists) would dismiss as a merely theoretical short-lived quantum effect of no conceivable relevance to phenomenal mind and the binding problem.

13Revonsuo, A. (1999) Binding and the phenomenal unity of consciousness. Conscious Cogn, 8:2, 173–85.

14Everett, H. (1957): Relative State Formulation of Quantum Mechanics, Reviews of Modern Physics, 29, 454–462.

15Antti, R. (2006). Inner Presence: Consciousness as a biological phenomenon. Cambridge, MA: MIT Press.

16Lindley, D. (1996) Where Does The Weirdness Go? Why Quantum Mechanics Is Strange, But Not As Strange As You Think. New York: Basic Books.

17Chalmers, D. (2014). The Combination Problem for Panpsychism. Advance online publication, consc.net/papers/combination.pdf.

18Moore, G. (2005). What is... a Brane? Notices of the AMS 52:2, 214.

19Singer, W. (2004) Synchrony, oscillations, and relational codes. In Chalupa, L. M. and Werner, J. S. (Eds.) The Visual Neurosciences. Cambridge, Massachusetts: MIT Press, 1665–1681.

20Pearce, D, (2010). Quantum Computing: The First 540 Million Years. Paper presented at the Science of Consciousness Conference, Tucson, Arizona.

21Riddoch, M. J., & Humphreys, G. (2004). Object identification in simultanagnosia: When wholes are not the sum of their parts. PCGN Cognitive Neuropsychology, 21:2, 423–441. doi:10.1080/02643290342000564.

22Zeki, S. (1991). Cerebral akinetopsia (visual motion blindness): A review. Brain 114, 811–824. doi: 10.1093/brain/114.2.811.

23Crick, F., & Koch, C. (2003). Framework for consciousness. Nature Neuroscience 6:2.

24Schwitzgebel, E. (2014). If materialism is true, the United States is probably conscious. Philosophical Studies, 172:7, 1697–1721. doi:10.1007/s11098-014-0387-8.

25Dennett, D. (2005) Sweet Dreams: Philosophical Obstacles to a Science of Consciousness. Cambridge, MA: MIT Press.

26Tegmark, M. (2000). Why the brain is probably not a quantum computer. Information Sciences, 128:3–4, 155-179. doi:10.1016/s0020-0255(00)00051-7.

27Wallace, D. (2012). The Emergent Multiverse: Quantum Theory according to the Everett Interpretation. Oxford: Oxford University Press.

28Rumelhart, D. E., & McClelland, J. L. (1986). Parallel distributed processing: Explorations in the microstructure of cognition. Cambridge, MA: MIT Press.

29Clark, A. (1989). Microcognition: Philosophy, Cognitive Science and Parallel Distributed Processing. Cambridge, MA: MIT Press.

30Tomasik, B. (April 23, 2014) This guy thinks killing video game characters is immoral. (D. Matthews, Interviewer). Vox Magazine. http://www.vox.com/2014/4/23/5643418/this-guy-thinks-killing-video-game-characters-is-immoral.

31Flanagan, B. (2003) Are perceptual fields quantum fields? Neuroquantology 3. Cf. Dirac, P.A.M. (1930/1958) The Principles of Quantum Mechanics. Oxford: Oxford University Press.

32Tegmark, M. (1996). Does the universe in fact contain almost no information? Foundations of Physics Letters, 9:1, 25–41. doi:10.1007/bf02186207.

33Schwindt, J. (2012) Nothing happens in the Universe of the Everett Interpretation arXiv:1210.8447v1.

34Wigner, E. (1960) The Unreasonable Effectiveness of Mathematics in the Natural Sciences. Communications in Pure and Applied Mathematics, 13, 1. New York: John Wiley & Sons, Inc.

35Sellars, W. (1956). The Myth of the Given: Three Lectures on Empiricism and the Philosophy of Mind. In Minnesota Studies in H. Feigl and M. Scriven (Eds.), The Philosophy of Science, Volume I: The Foundations of Science and the Concepts of Psychology and Psychoanalysis (253–329) Minneapolis, MN: University of Minnesota Press.

36Tononi, G. (2008). Consciousness as integrated information: A provisional manifesto. The Biological Bulletin 215, 216–242.

37Landauer, R. (1996) The physical nature of information. Phys. Lett. A 217, 188.

38Hameroff, S., Penrose, R. (March 2014). Reply to criticism of the “Orch OR qubit” – “Orchestrated objective reduction” is scientifically justified. Physics of Life Reviews 11:1, 94–100. doi:10.1016/j.plrev.2013.11.013.

39Bach, R., Pope, D., Liou, S., & Batelaan, H. (2013). Controlled double-slit electron diffraction. New Journal of Physics, 15:3, 033018. doi:10.1088/1367-2630/15/3/033018

40Arndt, M., Nairz, O., Vos-Andreae, J., Keller, C., Zouw, G. V., & Zeilinger, A. (1999). Wave–particle duality of C60 molecules. Nature, 401:6754, 680-682. doi:10.1038/44348.

41Romero-Isart, O., Juan, M. L., Quidant, R. & Cirac, J. I. (2010). Toward quantum superposition of living organisms. New J. Phys. 12, 033015.

42Schlosshauer, M. (2007). “Decoherence and the Quantum-to-Classical Transition” (1st ed.). Berlin/Heidelberg: Springer.

43Hameroff, S., Penrose, R. (2014). Consciousness in the universe: A review of the “Orch OR” theory. Physics of Life Reviews 11:1, 39–78. doi:10.1016/j.plrev.2013.08.002. PMID 24070914.

44Ghirardi, G.C., Rimini, A., Weber, T. (1985). A Model for a Unified Quantum Description of Macroscopic and Microscopic Systems. Quantum Probability and Applications, (L. Accardi et al. Eds.), Berlin/Heidelberg: Springer.

45Hameroff, S., Penrose, R. (2014). Reply to criticism of the “Orch OR qubit” – “Orchestrated objective reduction” is scientifically justified. Physics of Life Reviews 11: 1, 94–100. doi:10.1016/j.plrev.2013.11.013.

46Dewitt, B. S. (1970). Quantum mechanics and reality. Physics Today. 23:9, 30. doi:10.1063/1.3022331.

47Zurek, W. (2009) Quantum Darwinism, Nature Physics 5, 181–188 doi:10.1038/nphys1202.

48Campbell, J. (2010) Quantum Darwinism as a Darwinian process. arXiv:1001.0745.

49Jackson, F. (1986). What Mary Didn’t Know, Journal of Philosophy 83, 291–295

50Shulgin, A. and A. (1995). PiHKAL: A Chemical Love Story. Berkeley: Transform Press.

51Copeland, B. J. (2008) The Church-Turing Thesis, in The Stanford Encyclopedia of Philosophy, E.N. Zalta, (Ed.).

52Sander J.D., Joung J.K. (2014). CRISPR-Cas systems for editing, regulating and targeting genomes. Nature Biotechnology. doi:10.1038/nbt.2842. PMID 24584096.

53Shulgin, A. (2011). The Shulgin Index Vol 1: Psychedelic Phenethylamines and Related Compounds. Berkeley: Transform Press.

54Pearce, D. (2012). The Biointelligence Explosion, in Eden, AH; Moor, JH; Soraker, JH; Steinhart, E. (Eds.), Singularity Hypotheses A Scientific and Philosophical Assessment. Berlin/Heidelberg: Springer.

Ingo Niermann
WIE DIE WELT SICH SELBST AUSDENKT

Wenn mein Fuß auf einen Stein stößt, dann spüre ich den Fuß und den Stein. Ich bin mir beider bewusst. Aber nur mit dem Fuß fühle ich mich eins. Ich fühle mich bis in ihm. (Das kann ein Fuß sein, von dem ich nur annehme, dass er mir anhängt.) Ich kann mich auch wiederum mit dem Gedanken an meinen Fuß und mein Einssein überhaupt eins fühlen. Ich bin mir meines eigenen Bewusstseins bewusst. Ein Gedanke stellt Etwas dar. Ich denke an Etwas. Das kann Irgendetwas sein, so auch im Kurzschluss der Gedanke selbst. Im anderen Extrem ist das Etwas nur wieder ein Verweis: ein Zeichen.

Mittels Zeichen ist es möglich, bewusstes wie auch unbewusstes Denken zu repräsentieren. Wir können uns nie sicher sein, ob der andere, der sich über seine Sinneswahrnehmungen und Selbstreflexionen äußert, ihrer überhaupt bewusst ist. In unserem Verständnis all dessen, was nicht unser ganz persönliches Bewusstsein umfasst, brauchen wir uns daher um Bewusstseinsphänomene erst einmal gar nicht zu scheren. Zumal wir in der wahrgenommenen Welt beständige Gesetzmäßigkeiten auszumachen in der Lage sind, die Wahrnehmung selbst aber über den Umweg der wahrgenommenen Welt als unvollständig und entstellend erfahren. Subjektiv wird damit zu einem Synonym für unzuverlässig, objektiv für zuverlässig. Da eben nur jeder selbst Zugang zum eigenen Bewusstsein hat, entzieht es sich, nach wissenschaftlichen Kriterien, streng genommen als Forschungsgegenstand.

Noch strenger genommen kann es für uns auch keine zuverlässige Objektivität geben, denn sie muss uns immer erst bewusst werden. Doch eine solche von Platons Höhlengleichnis über Descartes’ Traum-Argument und Kants unergründliches Ding an sich bis hin zum funktionalen Wahrheitsbegriff des radikalen Konstruktivismus reichende fundamentale Skepsis bleibt ein philosophischer Luxus. Als zu groß und kontinuierlich erscheinen die naturwissenschaftlichen Fortschritte der letzten Jahrhunderte.

Zwar kann ich mir so wenig wie anderer Bewusstseine – der Plural ist sprachlich gar nicht vorgesehen – sicher sein, dass überhaupt etwas außer mein eigenes Bewusstsein existiert, und erst recht keiner wissenschaftlichen Gemeinde. Deshalb hat der Solipsismus, der nur das eigene Bewusstsein als wahr annimmt, - obgleich unwiderlegbar - philosophisch höchstens als Totschlagargument Relevanz. Und auch die Frage, was Bewusstsein abgesehen von sprachlichen und protosprachlichen Prozessen des logischen Denkens eigentlich ist, spielt, als ich 1988 an der Freien Universität in Berlin das Studium der Philosophie beginne, praktisch keine Rolle. In der Regel begreift man Bewusstsein, üblichen psychologischen Annahmen folgend, als ein emergentes Phänomen gewisser, noch genauer zu erkundender neuronaler Synchronisationsprozesse. Wer sich damit nicht zufriedengibt und weiterhin fragt, wie es sein kann, dass es überhaupt bewusste Empfindungen gibt (Leibniz's gap), wie es sein kann, dass ein loses neuronales Netzwerk eine Vielzahl (palette problem) homogener (grain problem) Empfindungen erzeugen kann, wie es sein kann, dass diese nicht nur als zusammenhängend wahrgenommen werden (binding oder combination problem), sondern dieses Einssein auch wieder bewusst reflektiert werden kann (das Problem, dass Selbstbewusstsein nicht nur epiphänomenal existiert, sondern sich artikulieren und damit materiell fortwirken kann), gilt als ein unverbesserlicher Metaphysiker, der noch an die Seele oder gar eine pantheistische Weltseele glaubt.

Auch von der Physik ist keine Antwort zu erwarten. Seit den letzten großen Eruptionen durch Relativitätstheorie und Quantenmechanik verharrt sie bereits an die hundert Jahre erfolgreich im Stadium der normal science, wie der Wissenschafsphilosoph Thomas Kuhn die Phase der Konsolidierung nach einem paradigm shift nennt. Die theoretischen Grundannahmen werden mit immer aufwendigeren Experimenten bestätigt und allenfalls um nicht verifizierbare Spekulationen wie etwa die String- oder Viele-Welten-Theorie erweitert. Für die Frage nach der Natur des Bewusstseins erklärt sich die Physik per se als nicht zuständig und nimmt damit ungeprüft Partei für Theorien, die dem Bewusstsein einen elementaren Charakter absprechen.

Ich weiche aus in die Literatur, bin fasziniert von den Bedingungen, unter denen wirtschaftliche Visionen Erfolg haben oder scheitern, und beginne in den nuller Jahren, auch für Staaten neue Visionen zu entwickeln. Auf Englisch wird daraus die Solution-Buchreihe. Ich nenne mein Vorgehen “speculative non fiction”, und ein Prinzip, das mir immer wieder erstaunliche Dienste leistet, ist, die Antwort auf ein Problem in einem anderen Problem zu finden. Darum frage ich mich bald: Könnte es nicht das rätselhafte Bewusstsein sein, das auf die Frage von Goethes Faust Antwort gibt, “was die Welt im Innersten zusammenhält”?

So tollkühn mir dieser Gedanke auch erscheint, bin ich mit ihm doch nicht allein. Mittlerweile hat David Chalmers es geschafft, eine neue Generation von Philosophen für das hard problem zu sensibilisieren, Bewusstsein physikalisch zu erklären, und ich erfahre nun von bereits auf William Kingdon Clifford, William James und Bertrand Russell zurückreichenden Ansätzen, das, wie Stephen Hawking es nennt, “fire in the equations”, also das, was die physikalischen Gleichungen eigentlich beschreiben, als basale sinnliche Phänomene zu begreifen. (Clifford spricht von einer sich aus "Mind-stuff" oder "faint beginnings of sentience" zusammensetzenden Welt, James von "primordial mind-dust".) Die Trennung von Geist und Materie wird zugunsten des Geistes aufgehoben.

Anzunehmen, dass alles, was existiert, bewusst ist, bedeutet keineswegs eine Rückkehr zum Animismus, da dieser zwar auch allen Dingen Bewusstsein zuspricht, aber, einer anthropozentrischen Sicht folgend, nur im Verbund mit Intelligenz und Leben. Nachdem wir dank Kybernetik bereits Leben und Informationsverarbeitung entkoppelt haben, können wir nun auch Bewusstsein und höhere Intelligenz entkoppeln und ersteres als ein elementares physikalisches Phänomen begreifen.

Die übliche Bezeichnung Panpsychismus für das Verständnis des Bewusstseins als elementarem Phänomen ist missverständlich, da sie traditionell dem Animismus nahestehende, pantheistische oder panvitalistische Positionen zusammenfasst. Um sich davon abzuheben, ist nun auch von Panexperimentalismus, Panprotoexperimentalismus oder Panprotopsychismus die Rede. Wer, wie Grover Maxwell, Galen Strawson oder David Pearce, betonen möchte, dass auch eine aus nichts als Bewusstsein bestehende Welt den physikalischen Gesetzen gehorcht, spricht von physikalistischem Idealismus.

Die großen Fragen, die sich bei diesen Ansätzen aufdrängen, sind abgesehen von der nach Leibniz’s gap dieselben wie bei der These, dass Bewusstsein ein emergentes Phänomen ist: Wo soll bei den großen Lücken zwischen den Elementarteilchen die Kontinuität herkommen? Woher kommt bei der geringen Zahl verschiedener Elementarteilchen die Vielfalt an Sinneseindrücken und Gedanken? Wie begreifen wir ein sinnliches Objekt oder uns selbst als zusammengehörig?

Zwar ist es naheliegend, eine Lösung in der Quantenphysik zu suchen, da ihr zufolge die Welt nicht aus diskreten Elementarteilchen, sondern Wellenfunktionen von Wahrscheinlichkeitsamplituden besteht, die über unbegrenzte Entfernungen hinweg miteinander verschränkt sein können. Nur scheinen sich Quantenphänomene in unserer Alltagswelt nicht bemerkbar zu machen, da chaotische Wechselwirkungen zwischen den Wellenfeldern kohärente Interferenzen in kürzester Zeit wieder zerstören, das heißt dekohärieren. Auf der Funktionsebene eines neuronalen Netzwerks scheinen sich alle Quantenphänomene statistisch herauszurechnen, sodass es praktisch den Gesetzen der klassischen Teilchenphysik gehorcht.

Ende der nuller Jahre lese ich von beachtlichen hunderte Femtosekunden andauernden Quantenkohärenzen bei der Fotosynthese – sogar bei Zimmertemperatur –, mit denen der verlustärmste Weg der Energieübertragung errechnet wird, und ich beginne mich ernsthaft zu fragen: Warum nicht auch im Gehirn? Nur sehe ich immer noch nicht, wie Femto- oder Picosekunden andauernde und dann immer wieder kollabierende Kohärenzen ausreichen sollen, den Eindruck zeitlicher Einheit für Prozesse zu erzeugen, die, um für uns überhaupt bemerkbar zu sein, wenigstens Millisekunden andauern müssen. Was wir als gegenwärtigen Moment prozessieren – eine Wortfolge, eine körperliche Bewegung, eine Melodie –, kann sogar Sekunden andauern. Natürlich ist es möglich, einen solchen Moment auch in sehr viel kürzerer Zeit zu prozessieren, und warum nicht in Femtosekunden. Doch während sich eine räumliche Darstellung beliebig verkleinern lässt, ohne dass es zu Brüchen in der Rückübersetzung etwa bei der Koordination körperlicher Bewegungen kommen muss, müsste sich ein schnelleres Bewusstsein immer neu mit der Realzeit synchronisieren und in der Zwischenzeit entweder aussetzen oder sich immer wieder (im skizzierten Fall milliarden- oder billionenfach) wiederholen. Und auch wenn sich die neue Sequenz der vorherigen Pause beziehungsweise Wiederholungen nicht bewusst zu sein braucht, würde sich im Falle immer wieder abbrechender Kohärenzen die Frage stellen, warum unser Bewusstsein nicht flackert.

Jetzt könnte ich wild spekulieren, ob sich nicht etwa längere, minuten- oder sogar stundenlange Quantenkohärenzen in zusätzlichen Dimensionen oder der dunklen Materie verstecken könnten. Stattdessen versuche ich erst einmal umfassend zu erkunden, welche Herausforderungen eine aus nichts als Bewusstsein bestehende Welt noch an unser physikalisches Weltbild stellt. Wenn alles Bewusstsein ist, reicht es nicht, für das Bewusstsein auch noch einen Platz zu finden. Vielmehr muss umgekehrt unser bisheriges physikalisches Weltbild sehen, wie es mit dem, was das Bewusstsein phänomenologisch alles zu bieten hat, zurechtkommt. Und siehe da: 2015 veröffentlicht der US-amerikanische Physiker Matthew Fisher eine Studie, derzufolge es möglich scheint, dass Verschränkungen der Spins von in einem Posner-Molekül eingeschlossenen Phospor-Ionen einen ganzen Tag lang in einer lebenden Zelle überdauern.

In der Regel begründen Philosophen ihre Annahme, dass Bewusstsein etwas physikalisch Elementares ist, nur ex negativo. Um sich nicht dem Verdacht der Esoterik auszusetzen, belassen sie es dabei, die Emergenz-These mit ihr besonders frappant widersprechenden Bewusstseinsphänomenen zu attackieren, die ihnen dann auf die eigenen Füße fallen. Doch als Literat theoretisiere ich außer Konkurrenz und habe keinen wissenschaftlichen Ruf zu verlieren. Diese Freiheit nutze ich für den Versuch, aus dem Bewusstsein heraus die Welt neu zu verstehen.

Wie David Pearce treffend schreibt, stellt der physikalistische Idealismus "Kant on his head", denn was sich uns in der Introspektion direkt erschließt ist genau das von Kant als unergründlich angenommene Ding an sich. Wir müssen nur Edmund Husserls phänomenologischer Reduktion (auch Epoché oder Einklammerung genannt) folgend die Frage nach der konkreten Bedeutung des Gedachten ausklammern, dann erschließt sich uns in der „Washeit“ - den Qualia – unserer Gefühle und Gedanken intuitiv die physikalische Welt. Dabei versuche ich die phänomenologische Reduktion noch einmal so weit zu reduzieren, dass ich den Anthropozentrismus des herkömmlichen Panpsychismus vermeide und nur das erfasse, was Bewusstsein elementar zu eigen ist. Alle weiteren Phänomene müssen sich davon – auch physikalisch – ableiten lassen. Die moderne Physik sollte nicht unserer Intuition widersprechen, sondern von ihr bestätigt und ergänzt werden.

Natürlich sind wir, wenn wir unser Bewusstsein als solches beobachten, genauso von sprachlichen und gedanklichen Mustern geprägt, wie wenn wir auf die Bedeutung unserer Bewusstseinsinhalte fokussieren. Aber immerhin sind wir uns einer solchen Verzerrung in der phänomenologischen Reduktion ständig bewusst, während auch radikale Konstruktivisten gar nicht anders können, als in ihrer Alltagswahrnehmung immer wieder in einen naiven direkten Realismus zurückzufallen. Nur wissenschaftlichen Kriterien kann die phänomenologische Reduktion nicht genügen, da sie sich weder standardisiert aufzeichnen noch wiederholen lässt. Ihre Ergebnisse können, aber müssen nicht wahr sein – mit anderen Worten: sie sind fiktional. So finden folgende Spekulationen hin zu einer theory of everything ihren angemessenen Ort in der Literatur. Dass diese Spekulationen auf die akademische Forschung Einfluss nehmen, ist im wahrsten Sinne Science-Fiction.

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Was kann ich an meinem Bewusstsein als unwesentlich ausklammern? Zunächst einmal mich selbst. Ich denke mich, wenn ich mir des Erlebens als solches bewusst werde, mich also als erlebend erlebe. Ich erinnere mich aber auch an einfaches, unreflektiertes Erleben von Washeit, das ich mir nur im Erinnern explizit zuordne.

Außerdem kann ich Raum und Zeit als unwesentlich ausklammern. Viele Wahrnehmungen wie Töne, Formen, Lust und Schmerzen implizieren Raum oder Zeit, aber Stimmungen tun dies nicht, und auch das Erleben als solches gibt keine Hinweise auf seine raumzeitliche Ausdehnung. Ich verorte mein Bewusstsein nur deshalb irgendwo in meinem Kopf, weil ich dort mein Gehirn weiß und sich an dessen Außenseite die mein Bewusstsein im körperlichen Ruhezustand beherrschenden Sinnesorgane für Sehen, Hören, Riechen und Schmecken befinden. Von drei Seiten dringen die Informationen auf mich ein, und in deren Mitte liegt mein Gehirn.

Ich brauche nur, wie in der Meditation, die Augen zu schließen und mich ganz auf ein abstraktes Prinzip zu konzentrieren, um einen Raum, Zeit und mich selbst ausklammernden Bewusstseinszustand herbeizuführen. Religiöse Interpretationen leiten aus diesem Zustand die Teilhabe an einer ewigen und unendlichen oder auch raum- und zeitlosen Weltseele ab. Statt dass Bewusstsein Raum und Zeit voraussetzt, könnte es auch andersherum sein. Der antike Philosoph Plotin begreift dementsprechend Raum, Zeit und Materie als niedere Manifestationen eines emanierenden Weltbewusstseins (Nous). Doch warum sollte diese Emanation begonnen haben? Ich weiß hier sowenig weiter wie bei der Frage, warum es Bewusstsein gibt.

Erst einmal weiter mit der Frage, was Bewusstsein minimal sein kann: Wenn ich erlebe, ohne dass ich selbst, Raum und Zeit mir präsent sind, dann bedeutet wahrzunehmen, die Qualia für wahr zu nehmen. Ich (nicht länger ausgeklammert) kann das Wahrgenommene nur als falsch - also verschieden - im Hinblick auf etwas jenseits meiner konkreten Wahrnehmung Angenommenes behaupten. Die Negation (wie auch die nicht-tautologische Affirmation) impliziert eine raumzeitliche Ausdehnung.

Obwohl sich die Qualia durch ein stufenloses Mehr-oder-weniger sowie ein Sowohl-als-auch auszeichnen, verstehen wir wahr und falsch als diskrete Bedingungen. Diese Logik leitet sich aus der visuellen und haptischen Erfahrung einer Welt ab, die – aus evolutionären Gründen – von klar umrissenen Objekten dominiert wird. Dabei ist die Physikern und Philosophen solch Kopfzerbrechen bereitende, als hochgradig kontraintuitiv geltende Heisenbergsche Unschärferelation mental das Alltäglichste von der Welt: Ich schwebe zwischen Zuneigung und Abneigung, Lust und Schmerz, und im nächsten Moment ist es ganz klar nur das eine, während ich das, worauf sich das Gefühl bezieht, schon gar nicht mehr richtig wahrnehme. Je mehr ich mich auf ein Detail konzentriere, desto unschärfer nehme ich den Rest wahr. Wenn ich lese, sehe ich wenige Worte auf einmal scharf. Wenn ich eine Seite auf einmal anschaue, sehe ich alle Worte scharf, kann aber nicht lesen. Und wenn ich einen längeren Satz als Ganzes verstehe, dann erscheint er mir eben nicht als Ganzes vor meinem inneren Auge.

Ob das Erleben stärker oder schwächer ist, könnte an meiner Sensibilität oder am Stimulus liegen – das kann ich nicht unterscheiden. Verstehe ich Zuneigung und Abneigung wörtlich – das heißt, physikalisch –, dann bedeutet Zuneigung, von etwas angezogen, und Abneigung, von etwas abgestoßen zu werden. Lust und Schmerz benennen entsprechende Gefühle, wenn ich mich gegenüber dem, was mich anzieht oder abstößt, nicht bewegen kann.

Nun nehme ich Musik und Bilder nicht, wenn sich meine Liebe zu ihnen steigert, als lauter oder greller wahr. Umgekehrt muss ihre Laut- beziehungsweise Lichtstärke meine Begeisterung nicht beeinflussen. Viele Wahrnehmungen sind intensiv, aber weder von einem Gefühl der Zuneigung noch der Abneigung begleitet. Ich erkläre es mir damit, dass sich verschiedene Zu- und Abneigungen weitgehend aufheben. Wenn wir älter werden, werden unsere Gefühle durchschnittlich steter und schwächer. Wie es Kindern noch ohne Weiteres möglich ist, kann aber auch ich mich unter Hypnose oder dem Einfluss psychedelischer Drogen glücklich in einen Flecken Rot versenken, und wenn er stärker leuchtet, dann hebt sich meine Stimmung proportional.

Ich habe den Eindruck, dass ich nur wenige Gefühle gleichzeitig haben kann. Es könnte sogar sein, dass ich sie eigentlich immer nur nacheinander habe, sich die Abfolge aber in der Selbstreflexion zu einem einzigen Moment verdichtet. So wie ich auch mein Blickfeld für weitaus größer annehme als das, was ich wirklich gleichzeitig sehen kann.

Nicht nur, dass Bewusstsein ohne Raum und Zeit denkbar ist. Es ist auch in der Lage, Raum und Zeit ein wenig zu überwinden, indem es raumzeitliche Ausdehnungen als eins wahrnimmt. Verschiedene Ausdehnungen lassen sich zusammen als eine weitere Ausdehnung wahrnehmen oder eine Ausdehnung als aus mehreren zusammengesetzt. Das ist die Grundlage für satzförmige Gedanken und logische Operationen. Die umfassendste phänomenologische Einheit ist mein Bewusstsein als solches.

Auch wenn es mir gelingt, die Bedeutung meiner Wahrnehmungen auszuklammern, und ich bei einem Baum nicht mehr an meine Ideen (bei Husserl: Noema) von Bäumen, Wurzeln, Stämmen, Ästen, Blättern, dem Wandel der Jahreszeiten etc. denke, sondern nur mehr verschiedene Braun und Grün sehe, wenn es mir gelingt, statt eines zwei Blickfelder zu sehen und statt eines Raums nur eine oder mehrere unverbundene Ebenen, so vereinheitliche ich diese noch immer als – in sich mehr oder weniger ähnliche – Flecken und setze sie – als untereinander mehr oder weniger ähnlich – in Bezug.

Wie bei der Intensität der Wahrnehmungen und Gefühle kann auch ihre Zugehörigkeit eine graduelle sein. Beim Farbverlauf weiß ich nicht recht, wo die eine Farbe endet und die andere beginnt. Mein Blickfeld nehme ich als eines wahr, ohne genau zu wissen, wo es überhaupt endet. Ohne es zu sehen, fühle ich, dass jemand neben mir steht.

Da meine Wahrnehmung eine unendliche Auflösung hat, steht alles Wahrgenommene in unendlichem Vergleich. Diese immense Rechenleistung – die von Quantencomputern ansatzweise erschlossen wird – muss der Grund sein, dass ich überhaupt eine Simulation meiner Umwelt erlebe. Denn diese Simulation genau so zu präsentieren, dass sie auf stimmige Weise wahrnehmbar ist, ist aufwendig, und so wird mir von meinen körperlichen Sinnesreizen nur ein kleiner Bruchteil bewusst.

Ich bemühe mich, alles Wahrgenommene als Teil eines raumzeitlichen Kontinuums zu denken. Meine Füße liegen verborgen hinter den angewinkelten Knien. Ich spüre ein paar Druckstellen, und ich verbinde sie in meiner Vorstellung zu zwei Füßen oder passe die Druckstellen in meine Vorstellung der Füße ein. Ohne dass ich mir die Rückseite von Dingen visualisieren kann, kann ich sie mir doch denken, so wie ich auch in meinem Körper Gefühle verorte oder in einer vertrauten Umgebung auch im Dunklen weiß, was wo ist. Husserl spricht von einem Mitvergegenwärtigen – der Appräsentation. Es gibt sie auch zeitlich, wenn ich etwa beim Hören von Musik die vorangehenden und nachfolgenden Töne mitdenke. Husserl spricht hierbei von Retention beziehungsweise Protention.

Meine Vorstellung vervollständigt nicht nur Lücken der sinnlichen Wahrnehmung, sondern reicht auch über sie hinaus. Das ist in zeitlicher Hinsicht die Basis für Rekonstruktionen und Prophezeiungen, in räumlicher die Basis für eine innere Kartografierung der Welt und für Selbstbewusstsein. Indem ich mich selbst als Wahrnehmenden mitdenke, kann ich alle meine Wahrnehmungen in Zweifel ziehen. Ich kann meine Vorstellungen für wahrer nehmen als das, was ich als sinnlich wahrnehme, oder kann Vorstellungen als bloße Fantasie abtun.

Beim Blick in die Spiegelung eines Spiegels erscheint eine infinite Regression. Müsste sich so nicht auch mein Bewusstsein in meiner Vorstellung immer kleiner ineinander schachteln? Doch es erscheint mir grundsätzlich nicht möglich, mir eine räumliche Spiegelung vorzustellen, wenn nicht jedem Punkt des zu spiegelnden Objekts die Information beigegeben ist, wie weit er vom Spiegel entfernt ist. Und ich glaube, es ist diese Unmöglichkeit, die uns Gedanken daran, was es mit unserem Bewusstsein auf sich hat, hat meiden lassen wie Katzen ihr Spiegelbild.

Fortsetzung folgt.