Alex Wendt takes a provocative step in Quantum Mind and Social Science: Unifying Physical and Social Ontology by proposing that quantum mechanics plays a role in all levels of the human and social world (as well as all life). And he doesn't mean in the trivial sense that all of nature is constituted by quantum-mechanical micro-realities (or unrealities). Instead, he means that we need to treat human beings and social structures as quantum-mechanical wave functions. He wants to see whether some of the peculiarities of social (and individual) phenomena might be explained on the hypothesis that mental phenomena are deeply and actively quantum phenomena. This is a very large pill to swallow, since much considered judgment across the sciences concurs that the macroscopic world — billiard balls, viruses, neurons — are on a physical and temporal scale where quantum effects have undergone “decoherence” and behave as strictly classical entities.
Wendt’s work rests upon a small but serious body of scholarship in physics, the neurosciences, and philosophy on the topics of “quantum consciousness” and “quantum biology”. An earlier post described some tangible but non-controversial progress that has been made on the biology side, where physicists and chemists have explored a possible pathway accounting for birds’ ability to sense the earth’s magnetic field directly through a chemical process that depends upon entangled electrons.
Here I’d like to probe Alex’s argument a bit more deeply by taking an inventory of the strong claims that he considers in the book. (He doesn’t endorse all these claims, but regards them as potentially true and worth investigating.)
- Walking wave functions: "I argue that human beings and therefore social life exhibit quantum coherence – in effect, that we are walking wave functions. I intend the argument not as an analogy or metaphor, but as a realist claim about what people really are. (3) ... "My claim is that life is a macroscopic instantiation of quantum coherence. (137) ... "Quantum consciousness theory suggests that human beings are literally walking wave functions. (154)
- "The central claim of this book is that all intentional phenomena are quantum mechanical. (149) ... "The basic directive of a quantum social science, its positive heuristic if you will, is to re-think human behavior through the lens of quantum theory. (32)
- "I argued that a very different picture emerges if we imagine ourselves under a quantum constraint with a panpsychist ontology. Quantum Man is physical but not wholly material, conscious, in superposed rather than well-defined states, subject to and also a source of non-local causation, free, purposeful, and very much alive. (207)
- "Quantum consciousness theory builds on these intuitions by combining two propositions: (1) the physical claim of quantum brain theory that the brain is capable of sustaining coherent quantum states (Chapter 5), and (2) the metaphysical claim of panpsychism that consciousness inheres in the very structure of matter (Chapter 6). (92)
- Quantum decision theory: "[There is] growing experimental evidence that long-standing anomalies of human behavior can be predicted by “quantum decision theory.” (4)
- Panpsychism: "Quantum theory actually implies a panpsychist ontology: that consciousness goes “all the way down” to the sub-atomic level. Exploiting this possibility, quantum consciousness theorists have identified mechanisms in the brain that might allow this sub-atomic proto-consciousness to be amplified to the macroscopic level. (5)
- Consciousness: "The hard problem, in contrast, is explaining consciousness. (15) ... "As long as the brain is assumed to be a classical system, there is no reason to think even future neuroscience will give us “the slightest idea how anything material could be conscious.” (17) ... "Hence the central question(s) of this book: (a) how might a quantum theoretic approach explain consciousness and by extension intentional phenomena, and thereby unify physical and social ontology, and (b) what are some implications of the result for contemporary debates in social theory? (29)
- The quantum brain: "Quantum brain theory hypothesizes that the brain is able to sustain quantum coherence – a wave function – at the macro, whole-organism level. (30) ... "Quantum brain theory challenges this assumption by proposing that the mind is actually a quantum computer. Classical computers are based on binary digits or “bits” with well-defined values (0 or 1), which are transformed in serial operations by a program into an output. Quantum computers in contrast are based on “qubits” that can be in superpositions of 0 and 1 at the same time and also interact non-locally, enabling every qubit to be operated on simultaneously. (95)
- Weak and strong quantum minds: "In parsing quantum brain theory an initial distinction should be made between two different arguments that are often discussed under this heading. What might be called the “weak” argument hypothesizes that the firing of individual neurons is affected by quantum processes, but it does not posit quantum effects at the level of the whole brain. (97)
- Vitalism: "Principally, because my argument is vitalist, though the issue is complicated by the variety of forms vitalism has taken historically, some of which overlap with other doctrines. (144)
- Will and decision: "In Chapter 6, I equated this power with an aspect of wave function collapse, viewed as a process of temporal symmetry-breaking, in which advanced action moves through Will and retarded action through Experience. (174) ... "Will controls the direction of the body's movement over time by harnessing temporal non-locality, potentially over long “distances.” As advanced action, Will projects itself into what will become the future and creates a destiny state there that, through the enforcement of correlations with what will become the past, steers us purposefully toward that end. (182)
- Entangled people: "It is the burden of my argument to show that despite its strong intuitive appeal, the separability assumption does not hold in social life. The burden only extends so far, since I am not going to defend the opposite assumption, that human beings are completely inseparable. This is not true even at the sub-atomic level, where entangled particles retain some individuality. Rather, what characterizes people entangled in social structures is that they are not fully separable. (208-209)
- Quantum semantics: "This suggests that the “ground state” of a concept may be represented as a superposition of potential meanings, with each of the latter a distinct “vector” within its wave function. (216)
- Social structure: "If the physical basis of the mind and language is quantum mechanical, then, given this definition, that is true of social structures as well. Which is to say, what social structures actually are, physically, are superpositions of shared mental states – social wave functions. (258) ... "A quantum social ontology suggests – as structuration theorists and critical realists alike have long argued – that agents and social structures are “mutually constitutive.” I should emphasize that this does not mean “reciprocal causation” or “co-determination,” with which “mutual constitution” is often conflated in social theory. As quantum entanglement, the relationship of agents and social structures is not a process of causal interaction over time, but a non-local, synchronic state from which both are emergent. (260) ... "First, a social wave function constitutes a different probability distribution for agents’ actions than would exist in its absence. Being entangled in a social structure makes certain practices more likely than others, which I take to involve formal causation. (264-265)
- The state and other structures: "The answer is that the state is a kind of hologram. This hologram is different from those created artificially by scientists in the lab, and also from the holographic projection that I argued in Chapter 11 enables us to see ordinary material objects, since in these cases there is something there visible to the naked eye. (271) ... Collective consciousness: "A quantum interpretation of extended consciousness takes us part way toward collective consciousness, but only part, because even extended consciousness is still centered in individual brains and thus solipsistic. A plausible second step therefore would be to invoke the concept of ‘We-feeling,’ which seems to get at something like ‘collective consciousness,’ and is not only widely used by philosophers of collective intentionality, but has been studied empirically by social psychologists as well. (277)
Quantum brain theory hypothesizes that quantum processes at the elementary level are amplified and kept in superposition at the level of the organism, and then, through downward causation constrain what is going on deep within the brain. (95)So the brain as a whole is in superposition, and only resolves with perception or will as a whole in an event of the collapse of its wave function. (He sometimes refers to "a decoherence-free sub-space of the brain within which quantum computational processes are performed" (95), which implies that the brain as a whole is perhaps a classical thing encompassing "quantum sub-regions".) But whether it is the whole brain (implied by "walking wave function") or a relatively voluminous sub-region, the conjurer's move occurs here: extending known though kinky properties of very special isolated systems of micro-entities (a handful of electrons, photons, or atoms) to a description of macro-sized entities maintaining those same kinky properties.
So the "brain as wave function" theory is very implausible given current knowledge. But if this view of the brain and thought cannot be made more credible than it currently is -- both empirically and theoretically -- then Wendt's whole system falls apart: entangled individuals involved in structures and meanings, life as a quantum-vital state, and panpsychism all have no inherent credibility by themselves.
There are many eye-widening claims here -- and yet Alex is clear enough and well-versed enough in relevant areas of research in neuroscience and philosophy of mind to give his case some credibility. He lays out his case with calm good humor and rational care. Alex relies heavily on the fact that there are difficult unresolved problems in the philosophy of mind and the philosophy of physics (the nature of consciousness, freedom of the will, the interpretation of the quantum wave function). This gives impetus to his call for a fresh way of approaching the whole field -- as suggested by historians of science like Kuhn and Lakatos. However, failing to reach an answer to the question, "How is freedom of the will possible?", does not warrant us to jump to highly questionable assumptions about neurophysiology.
But really -- in the end this just is not a plausible theory in my mind. I'm not ready to accept the ideas of quantum brains, quantum meanings, or quantum societies. The idea of entanglement has a specific meaning when it comes to electrons and photons; but metaphorical extension of the idea to pairs or groups of individuals seems like a stretch. I'm not persuaded that we are "walking wave functions" or that entanglement accounts for the workings of social institutions. The ideas of structures and meanings as entangled wave functions (individuals) strike me as entirely speculative, depending on granting the possibility that the brain itself is a single extended wave function. And this is a lot to grant.
(Here is a brief description of the engineering goals of developing a quantum computer (link):
Quantum computing differs fundamentally from classical computing, in that it is based on the generation and processing of qubits. Unlike classical bits, which can have a state of either 1 or 0, qubits allow a superposition of the 1 and 0 states (both simultaneously). Strikingly, multiple qubits can be linked in so-called 'entangled' states, in which the manipulation of a single qubit changes the entire system, even if individual qubits are physically distant. This property is the basis for quantum information processing, with the goal of building superfast quantum computers and transferring information in a completely secure way.See the referenced research article in Science for a current advance in optical quantum computing; link.)
(The image above is from a research report from a team which has succeeded in creating entanglement of a record number of atoms -- 3,000. Compare that to the hundreds of billions of neurons in the brain, and once again the implausibility of the "walking wave function" idea becomes overwhelming. And note the extreme conditions of low temperature that are required to create this entangled group; the atoms were cooled to 10-millionths of a degree Kelvin, trapped between two mirrors, and subjected to exposure by a single photon (link) And yet presumably decoherence occurs if the temperature raises substantially.)
Here is an interesting lecture on quantum computing by Microsoft scientist Krysta Svore, presented at the Institute for Quantum Computing at the University of Waterloo.