What follows is the second essay I wrote for the philosophy course I have just completed. I have included the bibliography just in case readers want to chase down my sources. I hope it is interesting and stylistically worth your while.
****
In a conversation at Princeton, Albert Einstein famously remarked to Abraham Pars, “Do you really believe that the moon is not there when you are not looking at it?” Einstein was reacting to the Copenhagen interpretation of quantum mechanics according to which subatomic particles lack certain properties until measured. He was reacting to idealist interpretations of physical reality. Although Einstein was opposed to the idea that reality might be observer-dependent, many interpretations of quantum mechanics assert just this. At the foundation of supposedly observer-independent science the observer may play a role.
Idealism can be understood as making two claims: first, that there is no material world, only ideas, and, second, that to be is to be perceived. (“Esse est percipi”.) (Chalmers, 2019). Idealism risks falling into solipsism, the worry that only one human subject exists in the world, and this worry must be staved off by supposing that every human being is a subject in his or her own right. However, even if we grant subjecthood to all humans, there remains the problem of whether objects that are unperceived by humans, such as the dark side of the moon, the interior of Mars, or anything in the universe that is purported to have existed prior to the evolution of humans, can really be said to exist or have existed. This problem can be resolved if we suppose that all material objects are subjects in their own right and always have been, and are perceiving all other material objects around them. If we suppose that rocks on Mars, their constituent parts or the greater cosmos of which they are a part, are conscious and can perceive each other, then it is possible to save the idealist precept that to be is to be perceived although we cannot go all the way from this to the claim that all that exists is ideas in the minds of subjects.
Although we cannot fully make the move from panpsychism to Absolute Idealism, forms of idealism fit very well with panpsychism, the theory that consciousness is ubiquitous throughout the universe. In this essay, I shall first describe the idealist form of panpsychism presented by Albahari (2019, 2022, 2026) and then shift to quantum mechanics, focussing on the work of Chalmers and McQueen (2021). My aim is to contrast the two views. Much of this essay concerns quantum mechanics and interpretations of quantum mechanics and so lies on the edge of what is normally taken to be philosophy. Nevertheless, it is relevant to any discussion of idealism. My primary purpose is to engage with the question of whether all reality can be described as “observer-dependent”. If all observers have minds and mentality is the most important characteristic of observation, then all reality is thus also “mind-dependent”, a thesis close to Absolute Idealism.
The most popular version of panpsychism holds that experience is fundamental. In G.E. Moore’s attempted refutation of idealism (Moore, 1903), he defines experience as a two-part relation between a subject, a consciousness, and a consciousness-independent object. (It is worth noting that if Moore’s argument goes through, it is a refutation of idealism but not of panpsychism.) However, because, as I will discuss, Albahari presents a case for a type of experience which transcends the subject-object distinction and because many philosophers view experience as a primitive term that we cannot fully define, in this essay I wish to treat the fundamental form of mentality as being perception rather than experience. The term perception can be defined in the following way. System A perceives system B if system B causally affects system A through some intervening medium and if system A is conscious and conscious of this effect and its cause. The intervening medium could be electromagnetic radiation, sound waves, physical contact, or something else. The effect that System B produces on System A could be permanent or it could be temporary. Related to perception is the concept of measurement, an important concept in quantum mechanics and therefore to this essay. I would define measurement as a special type of perception – it is perception in which attention is paid to the quantitative positions and characteristics of the observed system.
This definition of perception is compatible with materialism because most materialists believe in consciousness in addition to physical reality. Type A physicalists believe that consciousness weakly emerges from matter while Type B physicalists believe it strongly emerges. It is compatible with dualism because we can imagine some kind of spirit or soul that interacts with System A and can affect it and be affected by it. It is compatible with panpsychism if we suppose that both systems are conscious and that System B can potentially perceive System A.
Is this definition compatible with idealism? I claim that with a little amendment it is compatible with the form of idealism proposed by Miri Albahari.
Albahrari is an idealist whose metaphysics is influenced by her adherence to the Advaita Vedanta school of Hinduism. According to Advaita Vedanta, a universal consciousness exists which is termed Brahman and mystical revelation is achieved when it is realised that the Atman, a term loosely translatable as ‘soul’, is identical with Brahman. A part of this transcendental state of recognition is an overcoming of the illusion, Maya, that separate identities exist, and that the world is divided into subjects and objects. Albahari, in her writings, speaks about the mystical experiences of Hindu gurus such as Adi Shankara and implies that such a mystical state can be achieved through meditation. She terms her philosophy “Perennial Idealism”, an allusion to the work of Aldous Huxley. Albahari argues that this universal consciousness is aperspectival, in this way seeking to avoid the decombination problem of how a universal subject with its own perspective can give rise to human level subjects with their own differing perspectives.
Neutral monism, as first proposed by Bertrand Russell (1927), holds that all the stuff that makes up the universe might be neither entirely physical nor entirely mental but either both or neither. Modern panpsychists have extended this thesis by holding that matter has both mental and physical properties. Albahari argues that most panpsychists approach panpsychism from the physicalist direction, accepting the laws of physics as being hard laws and subscribing to the idea, inherited from materialism, that the minds of things are added extras to physical reality that have no role to play. When thinking about the nature of consciousness, they often tend to want to ground it in observer-independent physical structures sub specie aeternitatisi. They are thus adopting a view that can be called “realist panpsychism.” This paradigm leads directly to what she terms the “inner-outer gap problem”. Influenced by William James, Albahari points out that the experience of individual subjects is generally, outside of certain types of mystical experience, hermetically sealed off from the experience of other subjects. I can see the outer form of another human but do not have access to her inner experience. Even if we observe the same thing, the qualia present in the other’s mind is not directly perceivable by me. We tend to assume that inanimate objects are unconscious. Thus, in our ordinary involvement with the world, the distinction between subjects and objects comes naturally. Consciousness exists but is private, hidden from gaze. Furthermore, observer-independent reality is considered logically prior to experience
Albahari begins by reversing the order of causation. Although we might say that when Lucy enjoys chocolate, the physical occurrences in her brain involving neurotransmitters and nerve signals bring about, ground, cause the experience of her enjoying chocolate, Albahari argues that Lucy’s experience is the cause of her physical brain states rather than an effect of her brain states. She goes on to say, however, that “there is no less of a mystery in grounding observer-independent material structures in conscious minds than in grounding conscious minds in observer-independent material structures.” (Albahari, 2022) Albahari solves this problem by arguing that there are no observer-independent material structures at all. Her hypothetical example involves us imagining that while Lucy eats chocolate, a neuroscientist called Jim has opened her skull and is observing her brain. Albahari says that there is a mystery associated with supposing that there are mind-independent chemical and neuronal processes going on in her brain that causally arise from her private experience but says that this mystery can be mitigated if we suppose that there is no deeper reality to Lucy’s brain than the “cognisensory imagery” presented to Jim. We surmount the mind-body problem by saying that everything about Lucy is if not experienced by her then experienced by distal others such as Jim. To be is to be perceived. Albahari inconsistently says sometimes that an adherence to strong idealism solves both the (de)combination problems and the inner-outer gap problem and at other times that it does not fully solve the inner-outer gap problem. The claim that experience, mentality, is not just fundamental but all there is leads her to term her own idealist position “antirealist panpsychism”. She asserts that antirealism is more aligned with the spirit of the panpsychist project than realism and so should be more widely subscribed to.
Albahari’s idealism leads her to make a strong metaphysical claim about the world.
On panpsychism, the causal nodes are taken to be perspectival subjects with the power to bring about in themselves and other subjects the appearance of objects that obey natural laws. Causation can happen between different minds insofar as one subject, such as the cosmos, may exert an effect on the experiences of other subjects such as by eliciting in them the experience of an external world. What we ordinarily assume to be non-mental objects out there in space and time, in direct causal commerce with each other, are actually mental particulars (such as sequences of imagery) which arise as the manifestation of dispositional powers belonging to different subjects, such as the cosmos or ourselves. (Albahari, 2026)
Because Albahari endorses a view of the world which is full of subjects that experience and can influence the experiences of other subjects, the definition of perception I offered above holds. It holds if we replace the word “system” with “subject” and do not worry too much about the nature of the intervening media.
Albahari only ever makes passing references to quantum mechanics which is a pity because at least some interpretations of quantum mechanics align with her view of the world. Before I turn to interpretations of quantum mechanics, I shall give a brief description of some of its basic underlying notions. With respect to a particular particle, there is, at any given moment in time, a value associated with every point in space. The absolute square of this value integrated over a particular volume gives the probability of finding the particle in this volume as per the Born rule. The set of all these values is known as the wave function and if the absolute square is integrated over all space has the total value one, indicating that the probability of finding the particle somewhere in space is 100 percent. The wave function evolves deterministically according to the Dirac equation although physicists often use the Schrodinger equation instead, even though it is non-relativistic, because it is simpler. If a wave function is subject to boundary conditions, only certain quantised energy levels are permitted. For instance, the allowed energy levels of an electron orbiting a proton, as is found in hydrogen, are given by first stipulating that the potential energy of the electron is inversely proportional to its distance from the proton. The boundary conditions are that the wave function must be zero at a distance of zero from the proton, zero at infinity, and be spherically symmetric. The permitted energy levels and associated wave function are then calculated using the time-independent Schrodinger equation. (Serway and Jewett, 2004.)
However, this simple picture is complicated by measurements. If at some moment the position or another property of the particle in question is measured, we find that the wave function changes. If the measurement occurs at time t and the electron, say, is found to be at position x, then the wave function now has a very sharp peak at position x at time t and is now close to zero everywhere else. This indicates that the particle has been found to be, with great certainty, at position x at time t. This is often known as wave function collapse. We might imagine that, prior to the measurement, the particle had, say, 20 percent probability of being in a particular vicinity and then, after the measurement, now has a close to 100 percent probability of being in this vicinity because we seem to have found it there. A prevailing view is that the effects of measurement are non-local. For instance, if we are seeking to locate a particle and perform a measurement which determines with very great certainty that the particle is not in a particular volume of space, this measurement, although such a measurement will generally not lead to a sharp spike at some specific location in space and time, will still alter the wave function everywhere in space.
Physicists find what is known as wave function collapse extremely problematic and a number of what are known as interpretations of quantum mechanics have been established to try to explain its metaphysics. Starting around 1927, for many years, the dominant interpretation of quantum mechanics was the Copenhagen interpretation. According to this interpretation, the wave function is real and wave function collapse is real. Particles lack certain qualities until measured. A part of the so-called measurement problem is that the term ‘measurement’ was ill-defined then and is still ill-defined today. For physicists in the 1930s and 1940s, measurement was supposed to involve an interaction between the microscopic systems being measured and the macroscopic instruments doing the measuring. It was thought that the laws of quantum mechanics applied with respect to the very small but that traditional physics applied at the macroscopic level, the level of humans. Physicists were more or less instructed to not think about the philosophical foundations of quantum mechanics but to just “Shut up and calculate.”
In 1932, a different interpretation was proposed by Von Neumann. Von Neumann proved mathematically that the uncertainty associated with a quantum system is communicated to the macroscopic equipment doing the measuring. It is even then communicated to the perceptual organs of humans. Von Neumann thought that some kind of ‘cut’ in the causal sequence was required to explain wave function collapse and argued that it occurred when the quantum state, the superposition, reached the consciousnesses of the physicists performing the experiment. Thus Von Neumann suggested that consciousness caused wave function collapse. This idea was later picked up by Wigner (Wigner, 1961). Reality, according to this interpretation, is mind-dependent.
An alternative to both interpretations is the Many Worlds Interpretation (Everett, 1957). According to this interpretation, the wave function is real but wave function collapse is not. MWI is best explored by describing a hypothetical situation. Suppose a physicist, Bob, is performing an experiment to determine if an electron is in a Spin Up or Spin Down orientation. If the electron is well isolated from its environment, it is for a time in a superposition of both states, has some probability of being in one and some probability of being in the other. When it interacts with its environment however (such as with random air molecules and the measuring equipment) it becomes ‘entangled’ with this environment and any wave function we calculate must take this entanglement into account, an almost impossible task. This is known as ‘decoherence’. When decoherence occurs, the particle and its environment branch off into two real universes that cannot communicate with each other, one of which contains a Spin Up electron and the other a Spin Down electron. So far as Bob is concerned, the particle remains in a superposition until he checks the measuring apparatus. When he does, he becomes entangled himself with the superposition. Bob now exists in both universes – one in which Bob observes a Spin Up electron and a counterpart universe in which he observes a Spin Down electron. Suppose now that Bob has a friend, Alice, who lives on the opposite side of the world and knows that he intends the experiment but not its result. After the experiment is performed but before Alice knows the result, to her the whole system (electron + measuring equipment + Bob) is in a superposition. Suppose Bob now sends Alice a telegram telling her the result. Upon reading the telegram (or before if the decoherence ripple reaches her before the telegram) Alice becomes entangled with the whole system and now two Alices branch off, one of which is in the Spin Up universe and one of which is in the Spin Down universe. Decoherence cannot travel faster than the speed of light and the Many Worlds Interpretation is thus a local interpretation of quantum mechanics. In the Many Worlds Interpretation, no special role is played by consciousness.
I do not find the Many Worlds Interpretation persuasive. In my understanding of quantum mechanics, when a measurement is made the wave function of all particles involved changes. In Everett’s model though, the wave function may change smoothly and deterministically according to the Schrodinger equation but does not change suddenly, discontinuously, when a measurement is made. In fact, apart from certain experiments in which the system is well isolated from environmental influences, such as during double-slit interference experiments, according to Everett the wave function of all particles is entangled with all other particles in the universe and so cannot be established at all. Ultimately everything must be explained as resulting from the wave function of the universe as a whole. This would mean that all possible pasts and futures are equally real. Not only is a Bob who observes a Spin Up electron as real as the Bob who observes a Spin Down electron but Bob and Alice both are and are not friends and universes in which Bob and Alice do not exist at all are just as real as those universes where they do. Because the Many Worlds Interpretation does not explain why a single universe presents itself to our consciousnesses, why it seems to us that a definite universe exists rather than a mess of all possible universes, I believe it should be rejected.
Other interpretations of quantum mechanics are known as Objective Collapse theories. What is common to these theories is that, contrary to statements made by Warner Heisenberg and Max Born in 1927, the laws of quantum mechanics are regarded by proponents of such theories as incomplete and requiring amendment or modification. Einstein believed that there must be “hidden variables” to explain the appearance of wave function collapse. A modern Objective Collapse theory is proposed by Roger Penrose (1994). Penrose believes that because quantum mechanics and the Standard Model currently fail to take gravity into account, they must be incomplete. Penrose believes that the wave function is real and that wave function collapse is real, and that all systems collapse after a time period that is inversely proportional to the particle’s ‘Gravitational Self- Energy’, a quantity proportional to the mass of the particle squared and inversely proportional to the distance between possible particle positions. Because Objective Collapse theories involve modification to the laws of quantum mechanics, they are in principle experimentally testable but we currently lack enough precision to test Penrose’s theory.
Before I move onto a discussion of the theory proposed by Chalmers and McQueen, it is necessary to make a comment concerning the relationship between quantum mechanics and the macroscopic world because it has a bearing on whether quantum mechanics can be employed in favour of idealism. When quantum mechanics was developed, it was treated as a special case: the strange rules of quantum mechanics did not apply to the macroscopic world, a world which was thought could quite adequately be modelled as governed by classical physics. However today we have in our possession mathematical theories which affirm that the very small can have an effect on the much larger – chaos theory and the Butterfly Effect (Gleick, 1987). We can see how microscopic events can have macroscopic effects if we suppose, for instance, that Alice makes a million-dollar wager with Bob that the electron he observes will be Spin Up. We could also imagine a quantum event that changes a single nucleotide in an organism’s gamete, resulting in a superior organism that then spreads this beneficial mutation to descendants and thus leading to the evolution of its entire species. While apparently random events at a microscopic level tend, arguably, to cancel each other out, it is conceivable that such tiny random events can affect the whole world.
The recent theory by Chalmers and McQueen (2021) is surprising because it follows Wigner in supposing that consciousness causes wave function collapse but by assigning quantitative values to consciousness and to conscious states a new equation that modifies the Schrodinger equation can be formulated. Whereas Wigner’s proposal was viewed as something mystical, unscientific, the theory Chalmers and McQueen have developed is an Objective Collapse Theory and may be empirically testable. I can best outline this theory by describing how I understand it was developed. Wigner’s theory that consciousness causes wave function collapse led Chalmers and McQueen logically to suppose that consciousness is ‘superposition resistant’. This is to say that the brain of a human is always in one determinate state and any system it perceives, measures, near instantaneously collapses into one determinate state when the observed system becomes ‘entangled’ with the human’s brain. In order to bring consciousness into the domain of physics, they incorporated ideas from Integrated Information Theory (Tononi, 2012). Integrated Information Theory assigns a value to any system, represented by the Greek letter Phi, that indicates the amount of consciousness it has. Phi is related to the complexity of the system and one of its key principles is that conscious systems are presumed to be greater than the sum of their parts. Chalmers and McQueen claim that the higher the Phi value, the faster wave function collapse occurs, or, to put it another way, the greater the probability of wave function collapse occurring.
Although the notion that the higher the Phi value the quicker wave function occurs is retained in their fully developed theory, Chalmers and McQueen had to address two problems with their original model. The first was that if a human subject observes a superposition of two states such as a red sunset and a yellow sunset with equal probability the equation would not lead to wave function collapse and the observer is stuck in a superposition of both states. To resolve this issue, the more developed theory incorporates not just Phi values but also something known as Q-shapes. Q-Shapes are so-called because Q stands for qualia. Whereas Phi denotes something about the complexity of neural networks and other networks that process information, Q-shapes describe something about the state in which such networks are in. The developed “consciousness causes collapse” incorporates the idea that it is not just Phi but how different two different mental states are that triggers wave function collapse.
The second problem Chalmers and McQueen faced was the Quantum Zeno Effect. Sometimes a particle can be in one of two states, or one of two positions, such that at a time t the particle is almost certainly in that state and almost certainly not in the other. If the system remains unobserved the wave function changes smoothly and deterministically so that the probability of the particle shifting from the first of the two states to the second increases. However if a measurement of the particle occurs shortly after t this causes wave function collapse and the wave function snaps back to its original form, resetting the process. It can be mathematically proven that, in certain situations, the more often a system is measured (perceived) the less likely it is to change. The Quantum Zeno Effect can be extrapolated to all quantum systems. If a system is observed continuously, it cannot change because it is in continual state of wave function collapse. This result has been experimentally confirmed.
The reason that the Quantum Zeno Effect is a problem for the “consciousness causes collapse” interpretation as advanced by Chalmers and McQueen is that if a human brain is “superposition-resistant” then this is equivalent to saying that it is continuously being observed, measured (by itself perhaps?). This would mean that the mental state of a complex conscious organism cannot change. The way McQueen puts this is that if a person has a nap, he or she can never wake up (McQueen, 2017). To resolve this problem, Chalmers and McQueen postulated that the human brain can indeed enter into superpositions but only if the superpositions are small, meaning that the possible Q-states are similar, and only if they are brief.
The final form of the “consciousness causes collapse” equation changes the Schrodinger equation by introducing two additional terms to the right hand side. A contribution to their theory comes from another Objective Collapse Theory known as Continuous Spontaneous Localisation. According to this theory, particles are coupled to a kind of background noise that fills all space. This noise is random and is postulated to be responsible for the stochastic nature of wave-function collapse, the fact that the wave collapses randomly to one of many possible outcomes. In CSL, the second term is ‘mass-density.” The greater the mass density the faster the wave-collapse. This means that single particles like electrons can remain in superpositions for millions of years but complex systems like cats, dogs, tables, and people experience wave function collapse almost instantly. In their theory, Chalmers and McQueen keep the term involving the ‘noise’ but replace the term related to mass-density with a term involving Phi and the Q-shape, values derived from Integrated Information Theory.
The “consciousness causes collapse model” is innovative and superficially attractive. I wish to make three points concerning it. The first involves the notion of reductionism. Science, especially physics, is reductive – physicists seek to explain reality by finding the simplest relationships between the simplest ultimate constituents of the universe. The “consciousness causes collapse model” however does something very unusual. The behaviour of subatomic particles is explained by positing macroscopic quantities associated with very large complex systems, such as human brains, the macroscopic quantity denoted as Phi and the macroscopic geometric structures known as Q-shapes. It thus overturns a whole ideology that we can only explain the very small in terms of the very small and the very large in terms of the very small. In their theory, we explain the behaviour of the very small (an electron) in terms of the very large (the human brain). The second point is that the theory is almost but not quite micropanpsychist. A single electron has a Phi value of zero which means that it is not conscious and cannot by itself bring about wave function collapse either of itself or any system with which it interacts. However it is possible for a small number of atoms to be in a relationship with each other such that the system has a Phi value greater than zero. Although the consciousness of this system may be miniscule in size compared to the consciousness of a human, it is sufficient to bring about wave-function collapse. McQueen has argued that rudimentary conscious systems may have existed since shortly after the Big Bang and thus we can say that the universe, because it was entangled with conscious systems almost from its inception, has almost always had a determinate form (McQueen, 2017). Because of its embrace of Integrated Information Theory, a theory which seeks to establish a mathematical basis for consciousness that does not cling to the hubristic notion that only humans and other higher-level animals possess consciousness, the Chalmers-McQueen model opens the door to the idea that intelligence might be ubiquitous throughout the universe. Although not quite panpsychist, the theory is almost panpsychist. The third point is that the theory may be empirically tested in the future through the use of quantum computers.
Despite its attractions, I do not find this model persuasive. Partly this is because Integrated Information Theory is highly contested and has perhaps been debunked by Scott Aronson (2014). Perhaps a quantitative measure of consciousness that can be plugged into a physical equation can be established by another mathematical theory of consciousness but, so far as I am aware, only Tononi’s theory is on the field. More importantly I think the theory of Chalmers and McQueen rests on a faulty understanding of quantum mechanics. Although I am not sufficiently mathematically proficient to address the mathematics of their theory, I believe that the understanding of wave functions and wave function collapse assumed by Chalmers and McQueen is not correct and so it is on conceptual rather than mathematical grounds that I wish to challenge it.
My understanding of the wave function is that it is not physical but rather epistemic. I have been writing and thinking about quantum mechanics for many years and this is a hard-won position. Given certain data points, such as measurements, we postulate a wave function. This wave function then gives us the probabilities of future measurements. A wave function is simply a mental model that fits a certain set of data points, and so, rather than speaking about ‘wave function collapse’, we should instead talk of the results of measurements as predicted by the mathematics. When the future measurement is performed, this new measurement can either be included in the set of measurements already made, resulting in a new wave function, or not. An example may be helpful. When conducting the two slit interference experiment, before we can calculate the wave function, we need to know the width of the slits, the distance between them, the distance to the screen, and the momenta of the particles (electrons or photons) that we are firing through the slits. We then find wave functions that satisfy these specifications. If a particular electron ends up being found at a specific point on the screen, we can then postulate a wave function that takes this measurement into account. Calling it “wave function collapse” is misleading because although we find the electron we have fired through the slits at a particular location on the screen, according to the Heisenberg Uncertainty principle there is at the moment the electron is found at a particular spot on the screen a great deal of uncertainty concerning its momentum. Its momentum in momentum-space is smeared out over a great volume. The wave function thus does not disappear when the electron is found at a particular point on the screen. Rather it changes.
The view I am proposing is close to an interpretation known as Quantum Bayesianism. According to QBism, the wave function is subjective and can be construed as being an indirect measure of the degree of belief measuring subjects should ascribe to different outcomes. A measurement is simply an informational update in a subject’s mind concerning what the best wager is concerning a particle’s position and other properties at other times. Thus even though a measurement, in a sense, changes the wave function everywhere throughout all space, it is in actuality a local change because the wave function, if it exists anywhere at all, exists in the minds of the conscious subjects performing the measurements. If all reality is grounded in quantum processes, and if something like QBism is true, then we must conclude that the reality described by quantum mechanics is wholly mind-dependent. It is mind-dependent because measurements are, as I suggested earlier, necessarily consciousness-involving and because wave functions are themselves mental constructs. This might lead us to wonder if humans when engaging with the world, insofar as the world is quantum mechanical, are continually performing complicated quantum mechanical calculations is their heads. If this seems too implausible we could shift to another interpretation known as Quantum Pragmatism, the view that the wave function is a structure that best fits a set of measurements as calculated by a hypothetical perfectly rational being. If we make this shift, wave functions should be considered as things inhabiting a third space, the space in which we find mathematical theorems, a space containing truths that are neither mental nor physical but abstract, as per some theories of the ontological status of propositions. Although the debate between materialists, dualists, panpsychists, and idealists is one which assumes that the physical and mental are not only mutually exclusive but exhaustive of all phenomena, the best understanding of quantum mechanics may involve invoking such a third category.
There is an important and interesting implication of the Quantum Zeno Effect that I would like to briefly mention. If this effect is real, as experiments suggest it is, and if measurement is necessarily consciousness-involving, then if any system is perceived continuously it cannot change. This would imply, logically, that change, development, only occurs in the world when it goes unperceived. A useful analogy is to think of how movies are made up of still images separated by black frames but still give the impression of motion. We might think of how when light interacts with our retinas, it does so in discreet bundles, photons, with microscopic gaps in between. A mystical interpretation is conceivabale. We could think of the Hindu holy trinity, Brahman, Krishna, and Shiva (Sheldrake, 2026). Brahman is the ground of all consciousness, the Creator, Krishna is the God of Forms, the Preserver, and can thus be associated with the perceived, and Shiva is the God of Destruction, of change, and thus can be associated with the unperceived.
It seems that we can employ quantum mechanics in defence of the proposal that all physical processes are observer-dependent. I would like to return to Albahari’s position and the theory proposed by Chalmers and McQueen. Albahari is an antirealist panpsychist and Chalmers, although a dualist, is at least sympathetic to panpsychism, One attraction of panpsychism is that it seems to resolve a problem known as physical causal closure, the problem that because all physical effects are thought to have physical causes, there seems no role for consciousness. Panpsychism resolves this problem in a way that neatly coheres with compatibilism with respect to free will. Imagine, to recapitulate in different words an argument proposed by Albahari, that one has a friend who eats spaghetti bolognese at a particular restaurant every day. Just because her behaviour is predictable does not mean it is not freely chosen, freely willed. Albahari argues that the behaviour of apparently inanimate matter is predictable in a similar manner. Behind all material phenomena is not only experience but volition. The Chalmers-McQueen model is, in a different way, mind-dependent but also deterministic.
Albahari’s antirealism is evinced in the following quote.
When it comes to doing science with its experiments, theories, and predictions, one could adopt its observer-independent paradigm as a useful fiction. (Albahari, 2026)
Albahari does not address the observer-dependence explicit in many quantum theories. She thus has a very different perspective than Chalmers who is, by contrast, a realist and a quantum theories. Chalmers does not employ the fact of consciousness to undermine the mechanistic observer-independent paradigm of non-quantum physics but rather is seeking to bring consciousness under the umbrella of physics, in this way hoping to show that consciousness plays a role.
I would like to finish by relating the notion of physical causal closure and the closely related axiom known as the Principle of Sufficient Reason to quantum mechanics. The Many Worlds Interpretation is a deterministic theory in which physical causal closure and the Principle of Sufficient Reason obtain. The price one pays for believing in this theory is that one must suppose that all possible pasts, presents, and futures are equally real. Einstein famously said “God does not play dice with the universe” and argued that there must be hidden variables at work – both Continuous Spontaneous Localisation and the Chalmers-McQueen model are hidden variable theories. The hidden variables of these two theories are associated with the “noise” in both theories. Other interpretations however, such as the Copenhagen Interpretation, the original “Consciousness causes collapse” model proposed by Wigner, and QBism accept that there is a fundamentally aleatory component to quantum mechanics. When “wave function collapse” occurs, the outcome cannot, in principle , according to these interpretations, be wholly determined in advance. Thus, according to many interpretations, physical causal closure and the Principle of Sufficient Reason do not hold true. In my view, this allows for mentality and consciousnesses to play a causal role – room is left for the “causal nodes [..] to be perspectival subjects” in a mental or even supernatural guise. Given that interpretations of quantum mechanics that undermine the notion of physical causal closure and the Principle of Sufficient Reason have been around for over a century, it is surprising that this has not made a greater impression on many philosophers.
List of References
Aaronson, S. (2014, May 22). Why I am not an integrated information theorist (or, the Pretty-Hard Problem of consciousness). Shtetl-Optimized. https://scottaaronson.blog/?p=1799
Albahari, M. (2019). Perennial idealism: A mystical solution to the mind-body problem. Philosophers' Imprint, 19(44), 1–37
Albahari, M. (2022). Panpsychism and the inner-outer gap problem. The Monist, 105(1), 25–42. doi.org
Albahari, M. (2026). Does panpsychism entail anti-realism? The worm in the panpsychist apple. Religious Studies, 62(S33–S51), 1–19.
Chalmers, D. (2019). Idealism and the mind-body problem. In W. Seager (Ed.), The Routledge Handbook of Panpsychism (pp. 353–373). Routledge. [1, 2, 3, 4]
Chalmers, D. J., & McQueen, K. J. (2021). Consciousness and the collapse of the wave function(arXiv:2105.02314). arXiv. doi.org
Everett, H., III. (1957). "Relative state" formulation of quantum mechanics. Reviews of Modern Physics, 29(3), 454–462.
Gleick, J. (1987). Chaos: Making a new science. Viking.
McQueen, K. (2017). Does consciousness cause quantum collapse? Philosophy Now, (121), 17–20. [1]
Moore, G. E. (1903). The refutation of idealism. Mind, 12(48), 433–453. https://doi.org/10.1093/mind/XII.4.433
Penrose, R. (1994). Shadows of the mind: A search for the missing science of consciousness. Oxford University Press.
Russell, B. (1927). The analysis of matter. Kegan Paul, Trench, Trubner. [1, 2, 3]
Serway, R. A., & Jewett, J. W., Jr. (2004). Physics for scientists and engineers (6th ed.). Thomson Brooks/Cole.
Tononi, G. (2012). Integrated information theory of consciousness: An updated account. Archives Italiennes de Biologie, 150(4), 293–329. doi.org
Sheldrake, R. [RupertSheldrakePhD]. (2026, May 28). Holy Trinities: Threefold Models of Reality [Video]. YouTube. https://www.youtube.com/watch?v=0_n4Oc45NRc
Wigner, E. P. (1961). Remarks on the mind-body question. In I. J. Good (Ed.), The scientist speculates: An anthology of partly-baked ideas
(pp. 284–302). Heinemann.
