Bertrand Russell's Neutral Monism and Panpsychism

The appeal of both neutral monism and panpsychism is that they appear to have the makings of two theories which are (as the philosophical jargon has it) powerful, elegant and parsimonious . In other words, they join the philosophical dots. However, it also seems to be the case that these two theories are explicitly designed to join the dots. That is, both aim to ostensibly escape from various perennial philosophical problems. (Except for the fact that monism itself has an ancient history.) But surely there must be more to these theories than all that.

So, again, both neutral monism and panpsychism seem to offer (in a manner of speaking) “elegant solutions”. The main example of this is, of course, the gap between the physical and experience (or consciousness). And an almost obvious solution to that gap is to say that both the physical and experience (consciousness) are “grounded” in the same “neutral stuff”. Now how neat is that? Not that neat, really:

1) We still need to say what this stuff is.

2) And we still need to explain the link/s between this stuff and both the physical and consciousness.

All this is compounded when we discover that what are now called “intrinsic properties” (or neutral stuff) are seen in very different ways. For example, intrinsic properties have been seen as mental; physical; mental and physical; and, of course, neutral (i.e., unknowable).

History

All this seems like a resurrection of a discussion (or debate) within Anglo-American philosophy at a particular point in history — i.e., roughly from William James in the late 1890s to Bertrand Russell in the 1920s. Of course that doesn’t mean that it’s all wrong or false. But it could mean that philosophical fashions are often resurrected when philosophers have become bored of all the contemporary alternatives on offer.

Having put that limited time scale, monism itself (perhaps even neutral monism) goes back to Baruch Spinoza. The Dutch philosopher argued that matter and mind are two “modes” (or “aspects”) of the same substance. Much later (in the late 1960s and early 1970s), just to take one other example, we also had Donald Davidson’s “anomalous monism” in the philosophy of mind. Here again the mental and physical were seen as two aspects of the same… the same what?

So it’s strange that the “weird” views of contemporary panpsychists are sometimes seen to date back to Bertrand Russell, William James and even further. Or at least they do in very specific respects.

Both James and (arguably) Russell saw their “primal stuff” as being “pure experience”. Thus experience was indeed deemed to be “all the way down” (to use a phrase usually applied to relations) by these two philosophers. (See Gregory Landini’s later contrary view on this.)

We need to note the prefix “pure” here. It hints at the fact (or possibility) that we’re not talking about an x which has experience — but pure experience itself: experience which is unchained (as it were) from things and even from stuff. To put this within context, here’s Russell quoting James:

“‘My thesis is,’ [James] says, ‘that if we start with the supposition that there is only one primal stuff or material in the world, a stuff of which everything is composed, and if we call that stuff ‘pure experience.’…”

Then Russell offers his own take on James’s words above:

“James’s view is that the raw material out of which the world is built up is not of two sorts, one matter and the other mind, but that it is arranged in different patterns by its inter-relations, and that some arrangements may be called mental, while others may be called physical.”

This is a position which fuses both relationalism (or, to use an ugly word, arrangementism) and monism at one and the same time. We have both matter and mind because the same “primal stuff” is arranged in different ways. Or, in an alternative jargon, the nature of the relations between different bits of stuff produces either mind or matter. However, it’s not clear here why that stuff should also be seen as “pure experience” — as William James saw it.

Bertrand Russell’s Neutral Monism

Firstly, Russell said that his neutral monism is a monism

“in the sense that it regards the world as composed of only one kind of stuff, namely events”.

He then tells us that “it is [a] pluralism in the sense that it admits the existence of a great multiplicity of events”.

Bertrand Russell also puts the case for neutral monism at the very same time as he puts the case for for structural realism (without using that term) when he wrote the following:

“Physics is mathematical, not because we know so much about the physical world, but because we know so little: it is only its mathematical properties that we can discover.”

So Russell’s bottom line was that we have no access — either observationally or otherwise — to the “intrinsic characteristics” of objects/entities/etc. Instead “[w]hat we know about them” is simply “their structure and their mathematical laws”. That is, all we’ve got is structure and maths all the way down. That is an admission that mathematics is used in physics because we don’t know everything (as Russell himself puts it above) that is to be known about the object, condition, event, etc. under description or scrutiny. Thus mathematical equations and numerical values are the mere bones of what it is we describe. 

In addition, mathematics only deals with structures, behaviour and relations/interactions; not with intrinsic properties. Another way of putting that is to argue (as Russell more or less argued) that whatever we say in the mathematical physics, none of it leads to anything intrinsic.

As just stated, Russell’s supplied us with an important distinction between (as well as emphasis upon) intrinsic stuff and mathematical descriptions. Thus there are at least two obvious positions on these intrinsic properties:

1) Intrinsic properties are somewhat like Kantian noumena.

2) Intrinsic properties simply don’t exist at all.

It’s here that we also have two options available to us:

1) To become a kind of thing-eliminativist and say that (as ontic structural realists do) “Every thing must go.”

2) To adopt a quasi-Kantian line and say that there are noumena (or intrinsic properties); though the problem is that we don’t know anything about them.

Indeed, as with option 1), we can eliminate intrinsic properties, “substances” or noumena from our ontology entirely.

Russell himself put what can be called a Kantian stance on these issues when he wrote that all we have is what he calls the “effects of a thing-in-itself”. Thus Russell came to the conclusion that if we only have access to effects (i.e., Kant’s “phenomena”), then why not factor out the distinction between noumena (or intrinsic properties) and their effects (i.e., external properties) altogether? In other words, what’s left of noumena or intrinsic properties after all this? This question is scientifically elaborated upon when Russell tells us “[w]hat can be asserted” about these matters. He writes:

“When energy radiates from a center, we can describe the laws of its radiation conveniently by imagining something in the centre, which we will call an electron or a proton according to circumstances, and for certain purposes it is convenient to regard this centre as persisting, i.e. as not a single point is spacetime but a series of such points, separated from each other by time-like intervals. All this, however, is only a convenient way of describing what happens elsewhere, namely the radiation of energy away from the centre. As to what goes on in the centre itself, if anything, physics is silent.”

Nonetheless, Russell himself still had a problem with this scientific rejection of intrinsic properties. In basic terms, it simply can’t be a question of “relations all the way down”. Russell puts it this way:

“There are many possible ways of turning some things hitherto regarded as ‘real’ into mere laws concerning the other things. Obviously there must be a limit to this process, or else all the things in the world will merely be each other’s washing.”

This, then, is at odds with Lee Smolin’s “relationalism” (to take just one example). Here we are told a relationalist story as it specifically applies to particle physics. Smolin writes (in his Time Reborn):

“In the Standard Model of Particle Physics… the properties of an electron, such as its mass, which determines how much force is needed to change its motion. In the Standard Model, all the particles’ masses arise from their interactions with other particles and are determined primarily by one — the Higgs particle. No longer are there absolutely ‘elementary’ particles; everything that behaves like a particle is, to some extent, an emergent consequence of a network of interactions.”

Thus, in simple terms, particles have no “parts” (as Smolin puts it elsewhere). However, they do indeed have “properties”. These properties are all “relational” (or they’re the product of “interactions”). Mass, for example, is a relational property in that a particle’s mass is a product of its interactions with other particles — primarily with Higgs bosons. 

Gregory Landini on Bertrand Russell

According to the American philosopher Gregory Landini, Russell’s neutral monism is not a version of panpsychism. That is, Landini’s Russell didn’t believe in experience all the way down. (This case is complicated because Landini uses the word “qualia” — which is certainly putting the cat among the pigeons.) Instead:

“[Q]ualia never occur in transient particulars. In Russell’s view, qualia emerge from the series of brain states…colors, pitches, smells, tastes and textures are emergent properties of series of brain states.”

In other words, qualia belong to brain states. And brain states are highly complex. Another way of putting this is to say that qualia aren’t properties of basic “transient particulars”. So this, surely, is radically at odds with panpsychism.

Again, Landini argues that Russell believed that “qualia emerge from [a] series of brain states”. Thus x also be seen as being both qualia and Russell’s neutral stuff at one and the same time? Perhaps the problem here (again) is Landini bringing in the term “qualia” in reference to Russell. Having said that, Russell wrote about

“hearing a tire burst, or smelling a rotten egg, or feeling the coldness of a frog… particular colors and sounds”.

And aren’t these all examples of archetypal qualia? (Without Russell actually using the word “qualia”.)

Landini also argues that if neutral stuff (or his “transient physical particulars or events”) were deemed by Russell to have no experiences themselves (or not actually be experience — as with David Chalmers’ panprotopsychism), then we only get to experience proper (as it were) if it’s seen as being emergent. This is how Landini puts it:

“Qualia never occur in transient particulars. In Russell’s view, qualia emerge from the series of brain states…colors, pitches, smells, tastes and textures are emergent properties of series of brain states.”

There is a problem here though. If Russell saw

“seeing a flash of lightning…hearing a tire burst, or smelling a rotten egg, or feeling the coldness of a frog…particular colors and sounds and so on are events”

as being that primitive neutral stuff, then it can be argued that these mental events don’t need to be seen as emerging from anything. Indeed if they’re seen as neutral stuff, then they can’t be seen to have emerged from anything. Yet the problem is seeing x as primitive in the first place. In addition, even if such qualia are maximally simple in and of themselves, then it’s still the case that no consciousness state as a whole is made up of a single experience (or a single quale). Thus that whole mental state (or full consciousness) can still be seen to emerge from a set (as it were) of primitive qualia.

Here again we have the difficulty of emergence versus the primitivity (or “fundamentality”) of qualia.

If qualia (or Russell’s “percepts”) are primitive, then they can’t arise from brain states or indeed from anything else. This also seems to mean that this stuff is immediately available to us. So in what sense is it neutral when it’s also mental through and through? In that sense Russell’s neutral monism does indeed seem to square with panpsychism — despite Landini’s claims to the contrary.

The Given: Consciousness

One of the main points which unites contemporary panpsychists with Russell isn’t only the latter’s commitment to a monistic basic stuff, but also the commitment to the “fundamentality” (see Philip Goff) of consciousness/experience. (Or “percepts”, in Russell’s own case.) To all these philosophers, nothing is more (as it were) Given than experience, consciousness or percepts. Thus surely that is where we must start. Or, as David Chalmers put it, “Experience is a datum in its own right.”

I’ve just used the capitalised word “Given”. I did so because just as the Given was seen as being the basis of our epistemic knowledge (as well as for so much else), so experience (or consciousness) is seen to be the basis of ontology by panpsychists — or at least it gives panpsychists grounds for seeing its fundamental importance precisely because it is given to us. Thus panpsychists don’t move from the Given to epistemic truths or further chains of reasoning. They move from their own given to ontological conclusions about the nature of reality and mind.

In fact this link to the epistemological Given may not simply be analogical or ironic. After all, Russell himself argued that that a percept (or “quality”) isn’t something we can deduce from something else. In the jargon, it is a “primary datum”. So all this also has a foundationalist tinge to it in that Russell argued that all our knowledge of other (external) things is inferred from (or based upon) these precepts (or qualities). In other words, percepts (or experience) is the place we simply must start from.

I’ve spoken of both epistemology and ontology here. Yet this philosophical position also impacts more directly on the philosophy of mind as a whole. Thus, if we return to Russell again, it can be argued (according to Russell) that we can’t explain qualities (or percepts) in terms of the brain states that ground them if they are the primary data in the first place… Or perhaps we can… Yet it’s still the case that Russell might have also been right in arguing that the direction of the explanatory arrow must be from his percepts (or qualities) to brain states, rather than from brain states to percepts. 

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Notes

1) Bertrand Russell did seem to offer a third option: that intrinsic features are indeed emergent. In other words, we can never move from anything physical to anything mental. Or, in Russell’s own words, we

“cannot conceivably… prove that there are visual events, or auditory events, or events of any of the kind that we know by perception.”

Thus there’s no royal road from mathematical descriptions to the qualitative features of mentality because there’s always an “explanatory gap” between these two realms.

2) The move from consciousness to the physical (as well as vice versa) is found in integrated information theory.

Integrated information theorists (IIT) claim to start with consciousness and then move to the physical (or to brain states). It’s very hard, intuitively, to see how it would be at all possible to move to the postulated physical aspects (i.e., not bases or causes) of a conscious state. How would that work? How can we move, even in principle, from consciousness (or phenomenology) to the physical aspects of that consciousness state? If there’s a ontological/explanatory gap between the physical and the mental; then there may be (or is) an ontological gap/explanatory gap between consciousness and the physical. (There will be epistemological gaps too.) So how does this IIT inversion solve any of these problems?

The trick is supposed to be pulled off by an analysis of the (structural) phenomenology of a conscious state (or experience) and then accounting for it with the parallel state of the physical system — which is the physical “aspect” of that conscious state. But what does that mean? The ontological/explanatory gap, sure enough, shows its face here just as much as it does anywhere else in the philosophy of consciousness. Isn’t this a case of comparing oranges with apples — only a whole lot more extreme?

An additional problem is to explain how the physical modes (or aspects) of a conscious state must be “constrained” by the properties of that conscious state (or vice versa?). Again, what does that actually mean? In theory it’s easy (in many cases) to find some kind of structural physical correlates of conscious states. The problem would be to make sense of those correlations.

It doesn’t immediately help, either, when IIT employs quasi-logical terms to explain and account for these different aspects (or modes) of the same thing. Can we legitimately move from the axioms of a conscious experience to the properties (named “postulates”) of the physical modes (or aspects) of that conscious experience? Here we’re meant to be dealing with the “intrinsic” properties of experience which are then tied to the properties of the physical aspects (or modes) of that experience. Moreover, every single experience is meant to have its own axiom/s.

Nonetheless, if an axiomatic premise alone doesn’t deductively entail (or even imply) its postulate, then why call it an “axiom” at all?

Tononi (2015) explains this is terms of “inference to the best explanation” (otherwise called abduction). Here, instead of a strict logical deduction from a phenomenological axiom to a physical postulate, the postulates have (merely) statistical inductive support. Tononi believes that such an abduction shows us that conscious systems have “cause-effect power over themselves”. Clearly, behavioural and neuroscientific evidence may (or will) show this to be the case.

Does Philip Ball Really Move Beyond Quantum Weirdness?

In 2018, the science writer Philip Ball had a book published called Beyond Weird: Why Everything You Thought You Knew About Quantum Mechanics is Different.(Did Ball think that the word “wrong”, unlike “different”, was too in-your-face?) In that book he downplays the “weirdness” of quantum mechanics and stresses new approaches to its interpretation. This piece, however, doesn't use Ball's Beyond Weird. Instead it relies on his articles, blogs and a seminar he gave for The Royal Institution. However, it does focus on some of the same issues.

More specifically, this piece concentrates on what Christopher Fuchs calls “the grimacing and posturing” that quantum mechanics often brings about. In that sense, it inevitably focuses on the Copenhagen interpretation; which Ball somewhat favours. It also deals with the Schrödinger's cat thought-experiment; the specifics of wavefunctions; and “informational theory” as it's applied to quantum mechanics. All this is embedded within a discussion of philosophical anti-realism, which (to me) is a useful and even ideal position to adopt within the context of quantum mechanics. (Seeing the Copenhagen interpretation in anti-realist terms is, of course, hardly original.)

The No-One-Understands-Quantum-Mechanics Meme

The physicist Christopher Fuchs (as quoted by Philip Ball and referred to earlier) expresses the problem of quantum mechanics in terms of “all the posturing and grimacing over [its] paradoxes and mysteries”. In other words, for the layperson especially, that posturing and grimacing seems to have become the very essence of quantum mechanics... And perhaps this is even the case for some physicists too.

And from that quantum weirdness there follows the no-one-understands-quantum-mechanics refrain. That's why Philip Ball uses Richard Feynman's often-quoted words:

“I think I can safely say that no one understands quantum mechanics.”

Ball picks up on the bizarre nature of this statement when he says that “[a]t that point, no one alive knew more than Richard Feynman about quantum mechanics”. He concludes: “What hope is there, then, for the rest of us?”

So why, exactly, does no one understand quantum mechanics? Indeed is it the case that no one understands quantum mechanics? And what does it mean not to understand quantum mechanics?

To be honest, I find Feynman's remark rhetorical; as I suspect Philip Ball does. After all, it's fairly well-known that Feynman didn't have too much time for the interpretations¹ of quantum mechanics, let alone for the philosophy of quantum mechanics. In other words, Feynman knew all (or at least most) of the relevant maths. “The trouble was”, as Ball puts it, “that's all he could do”.

On the other hand, from a purely scientific point of view, it's easy to agree with Feynman. So it's not a surprise that Ball says that “[s]ome scientists feel the same way today”. Many scientists, in the words (quoted by Ball) of the physicist David Mermin, also say “shut up and calculate”. Ball himself writes:

“Quantum theory works. It allows us to calculate the shapes of molecules, the behaviour of semiconductor devices, the trajectories of light, with stunning accuracy.”

Thus the “theory works”; though “without our knowing what it's about”. And that surely wouldn't be such a bad thing if physicists believed that there's no real answer to the what-is-it-about question. Perhaps some (or even many) do believe that.

So what do the words, “What the maths mean”, mean? What does the maths describe? What is there beyond the maths (if anything)?

Does the mathematics alone give us a full understanding?

The Copenhagen Interpretation & Anti-Realism

Albert Einstein famously asked whether the moon continued to exist when we stopped looking at it. He said:

“[I can't accept quantum mechanics because] I like to think the moon is there even if I am not looking at it."

Einstein's moon is also a good way of putting the ostensible problem with philosophical anti-realism. However, no anti-realist has ever argued (as far as I know) that the moon ceases to exist when we stop looking at it. (That's what idealists argue.) Instead, let Ball himself express the anti-realist position. He says:

“It now seems that something is there when we don’t look, but exactly what is there is determined only when we look.”

In other words, there's no description of the moon “as it is in itself”. Everything we say about the moon is theory- and observer-relative. But this doesn't in any way factor out the moon as a physical object which is, indeed, independent of minds.²

To change direction.

My position is that the anti-realist stance on “the world” (or “nature”) is similar to the Copenhagen interpretation of quantum mechanics. However, whereas Niels Bohr and others might have mentioned measurements, experiments and whatnot; anti-realists have talked of verification, observation, the “public nature of meaning”, etc. Indeed these differences in jargon may not count for much; at least within this limited context.

So let Philip Ball put the “Copenhagenist” interpretation of quantum mechanics in its most graphic form:

“In this comment [from Niels Bohr] lurk all the notorious puzzles and peculiarities of quantum theory. It seems to be an incredibly grandiose, self-obsessed image of reality: nothing exists (or at least, we can’t say what does) until we bring it into being. Isn’t this the antithesis of science, which assumes an objective reality that we can examine and probe with experiments?”

One can see the problem with the Copenhagen interpretation when it's expressed in that way. Yet Ball lays his cards on the table about both this interpretation and his positive view of it. He writes:

“It’s perhaps for this reason too that I think there are misconceptions about the Copenhagen interpretation. The first is that it denies any reality beyond what we can measure: that it is anti-realist. I see no reason to think this.”

Ironically, Ball then puts the anti-realist position in the most explicit way possible when he tells us that

“[a]t the root of the matter is the issue of whether quantum theory pronounces on the nature of reality (a so-called ontic theory) or merely on our allowed knowledge of it (an epistemic theory)”.

Perhaps Ball should brush up on his contemporary philosophy. Most/all anti-realists don't “deny any reality beyond what we can measure”. They say (to put it simply) that this “mind-independent” reality serves hardly any purpose. And anti-realists also believe this for similar reasons to that given by Niels Bohr (whom Ball then quotes). So perhaps, like so many others, Ball is guilty of fusing anti-realism with idealism - or even with postmodern quackery!

Indeed many/all anti-realists class their position as “epistemic” too. Or, rather, it can be seen as an epistemic position on ontology. (Some may see that as almost being oxymoronic.)

So since we have made that point, let Ball himself put the “epistemic” position of the Copenhagen interpretation. He writes:

“Ontic theories, such as the Many Worlds interpretation, take the view that wavefunctions are real entities. The Copenhagen interpretation, on the other hand, is epistemic, insisting that it’s not physically meaningful to look for any layer of reality beneath what we can measure.”

Philosophical anti-realists would be (more or less) happy with that quote. So, again, it's odd that Ball seems to have a negative view of anti-realism. Perhaps this boils down to the brazen technical term that is “anti-realism”. After all, this term can be read as a philosophical position that is against the real!

And in the following quote we can again see why so many people conflate both the Copenhagen interpretation of quantum mechanics and philosophical anti-realism with idealism. Ball writes:

“Pascual Jordan, one of the physicists working with Niels Bohr who helped to define the new quantum world view in the 1920s, claimed that 'observations not only disturb what has to be measured, they produce it… We compel [a quantum particle] to assume a definite position.' In other words, Jordan said, 'we ourselves produce the results of measurements'.”

One can understand the idealist smell of the quote directly above. Nonetheless, the fact that “'observations not only disturb what has to be measured, they produce it” doesn't mean that that there wasn't a reality (or a something) which was measured in the first place. There was. That something (John Locke's “Something, I know not what”?) was disturbed. So there's an acceptance here that there was a something which was disturbed. It's not as if this something was created out of the blue. After all, the very words “disturbed” and “measured” show us that there was something that was disturbed or measured! Stressing observations or measurements clearly doesn't factor out what is that's observed or measured.

Ball continues:

“People might read [anti-realism!] into Bohr’s famous words: 'There is no quantum world. There is only an abstract quantum physical description.' But it seems to me that the meaning here is quite clear: quantum mechanics does not describe a physical reality. We cannot mine it to discover 'bits of the world', nor 'histories of the world'. Quantum mechanics is the formal apparatus that allows us to make predictions about the world.”

More relevantly and importantly:

“There is nothing in that formulation, however, that denies the existence of some underlying stratum in which phenomena take place that produce the outcomes quantum mechanics enables us to predict.”

An anti-realist (again) wouldn't have a deep problem with any of that. The anti-realist, and perhaps even Niels Bohr, would say that we can't know Kantian noumena (Bohr and Ball both mention Kant) – i.e., the world “as it is in itself”. Though, again, instead of the Copenhagen talk of “predictions”, anti-realists would simply emphasise verification, observations, intersubjectivity, etc. Bohr himself backed this up when he famously said (quoted by Ball) that

“'[i]t is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature'”.

We can now conclude by saying that there's nothing beyond measurement (or beyond observation, verification, experiment, etc.) Or, rather, there is; though there may as well not be. Why? Because when it comes to noumena (for want of a better and more up-to-date word), there's nothing we can say about it. (Though Kant did say a lot about noumena.)

According to Ball, Christopher Fuchs goes further than this and says that

“standard Bayesian probability theory assumes, probabilities – including quantum probabilities – 'are not real things out in the world; their only existence is in quantifying personal degrees of belief of what might happen'”.

Furthermore:

“This view, he says, 'allows one to see all quantum measurement events as little ‘moments of creation’, rather than as revealing anything pre-existent.'...”

In a certain sense, this is stronger than anti-realism in that an anti-realist would never feel the need (I guess) to use a phrase like “moments of creation”. Thus we accept the “pre-existent” without also saying that we can “reveal” it in its complete fullness. Indeed if we don't reveal the pre-existent, then what point does it play? Kant, for one, gave many reasons to accept the importance of noumena – or of the preexistent. Fuchs, on the other hand, appears to erase it from the picture.

This is very tricky. If the pre-existent were different, then surely the “moments of creation” would be different too. And if that's the case, then how can the pre-existent be entirely erased from the picture? Clearly these moments of creation can't be autonomous. They are restrained by the pre-existent. Thus any creation carried out by a physicist is restrained by – and dependent upon – the preexistent. In other words, if we take Fuchs literally and non-rhetorically, his position is essentially idealistic!

Schrödinger's Cat

Philip Ball applies more or less the same arguments found above to the specific and well-known case of Schrödinger's cat.

First of all Ball tells us that

“in neither the Copenhagen nor the Many Worlds interpretation is the cat 'simultaneously alive and dead'”.

In more detail, Ball says that

“I think Bohr might have said something along the lines that 'Observation allows us to speak about the classical state of the cat. And look, it is a dead one!'."

In other words, until we get information about the cat, we don't know if it's alive or dead. It's not the case that it's both alive and dead at one and the same time (i.e., before we gain that information). However, until we get that information (as with anti-realism), the cat may as well be both alive and dead... in a manner of speaking!

Ball also offers up a more original take on the cat scenario. When one reads it, it seems extremely simple yet also powerful.

Basically, in quantum mechanics, why the hell are we talking about alive and dead cats in the first place? Sure, this was meant to be a colorful thought-experiment (i.e., against a certain take on quantum mechanics). However, it's a thought-experiment which many people don't really take to be a thought-experiment. In Ball's own words:

“In order to be able to talk about the [cat] scenario in quantum terms, we need to be able to express it in quantum terms. But we can’t, because 'live cat' and 'dead cat' are not well-defined quantum states.”

I don't know about “well-defined quantum states”: a live cat and a dead cat (both together or separately) don't seem to be quantum states at all. Perhaps that doesn't matter. After all, what's happening here is that we're applying a quantum-mechanical situation (or possibility) to the “real world” - to a cat! And what's wrong with that?

Again, Ball's point seems to be very simple. And, as with so much in philosophy, the simple only seems simple after it is stated. Thus Ball continues:

“What quantum property is it, exactly, that characterizes the superposition state, and that will enable you, unambiguously and in a single shot, to distinguish the two classical states? Live and dead are not quantum variables, and I’m not at all sure that they can be correlated even in principle with quantum variables that can be placed in superposition states.”

Yes, the question really is blindingly simple:

What exactly is it for a cat (or anything else) to be both alive and dead at one and the same time?

If we can't even say what we mean in the first place, then what exactly are we talking about? This isn't a philistine (or “positivist”) rejection of “modal theorising” or though-experiments: it's just a demand that we define our terms, concepts or variables before we get the ball rolling.

Interestingly enough (especially in terms of philosophy), Ball focuses on logic and (sort of) plays down the maths of the quantum-mechanical cat scenario. Firstly he states:

“The paradox lies not in 'two states at once', but in 'two contradictory states at once'. He [Schrödinger] was pointing not to 'weird behaviour' predicted by quantum theory, but to logical paradoxes.”

Forget paraconsistent or dialethic logics here (which can be deemed to be pragmatic logics when it comes to quantum mechanics – see W.V.O. Quine and Graham Priest), Ball is asking us logical questions here. We have some kind of clash between logic and maths. Thus:

“David Deutsch and Max Tegmark say, ah language! What should we trust more, language or maths? Contingent sounds, or timeless equations?”

Yet Ball argues that “here language is articulating something that underpins maths, which is logic”.

If you go with the maths rather than the logic (as it were), then we'll inevitably have some strange scenarios to deal with. Ball cites the physicist Brian Greene's position on the cat again. Greene is quoted as saying: “Your cat is dead, but your cat remains alive.” What's more, Greene adds: “That is you too!”. Yes, “[t]hey are both you”!

Ball delves even more into logic when he says that “individual identity is a logical construct”. He then says that “[y]ou can’t wish it away with fantasies about 'other yous'”. (I'm not sure this is entirely a case of logic trumping maths. Philosophy - or “conceptual analysis” - comes into the equation too.)

Wavefunctions

Philip Ball quotes physicist Maximilian Schlosshauer to back up his “Copenhagenist” position on wavefunctions. Like (it can be argued) Louis de Broglie and Max Born before him, Schlosshauer is quoted as saying that the

“whole talk of waves versus particles, quantization and so on has made many people gravitate toward interpretations where wavefunctions represent some kind of actual physical wave property, creating a lot of confusion”.

Indeed Schlosshauer concludes by saying that “[q]uantum mechanics is not a descriptive theory of nature”. In other words, there is no literal or physical reality which the wavefunction captures. The wavefunction is a product of our knowledge or “information” and also a “mathematical object”. And we only know any actualities (not the probabilities) when the wavefunction is “collapsed” - perhaps not even then.

According to Ball himself, a wavefunction doesn't tell us what is. It tells us what “we would expect to find”. That is, if we do x, then we will find y or z. If we do y, then we will find something else.⁴

There's a temporal division here. We have a certain experimental situation. A wavefunction is constructed (if that's the correct way of putting it) and applied to that experimental situation. That wavefunction tells us what “we would expect to find” given the many variables involved. Then the wavefunction is collapsed – i.e., a measurement is made. That means that there's a gap between that original situation and the final measurement. (Indeed there's also a gap between a measurement and how that measurement is interpreted.)

It actually seems like a crude mistake to conflate where particle x could be with that particle actually being in all the places it could be. Or, more correctly, it's not a case of particle x possibly being in all the places it could be in: it's seen as being in a lot of places at the same time. If this isn't about probabilities but actualities, then there's also a distinction to be made between where x could be and where x is. So how on earth can we argue that saying

“x could be in many places”

is the same thing as saying that

“x actually is in all these places it could be at the same time”?

Thus a particle is not “in many places at once”. It could be in many different places – but not at one and the same time. Being in difference places at one and the same time is not the same as the possibility it could be in many different places.

In addition, particle x possibly being in either spin up or spin down, for example, isn't the same as that particle actually being in spin up and spin down - at one and the same time.

Information and Spin States

Philip Ball also stresses the importance of what he and others call “information”. He contrasts information with “knowledge”. (Doesn't one need knowledge about information?)

Ball allows Christopher Fuchs (again) to express his own informational view. He writes:

“[Christopher Fuch's] approach argues that quantum states themselves – the entangled state of two photons, say, or even just the spin state of a single photon – don’t exist as objective realities. Rather, 'quantum states represent observers’ personal information, expectations and degrees of belief', he says.”

In other words, a photon isn't in both spin up and spin down at one and the same time. Instead, we simply have the “information” that it can be either in spin-state up or spin-state down. Until a measurement is made, we simply don't know which one it is in.

As stated, all this ties into the stress which Ball places on information. Indeed, despite his view on philosophical anti-realism, information plays almost the same role as observation, verification and whatnot do in anti-realist philosophy.

Ball cites the physicists and philosopher of physics Jeffrey Bub (of the University of Maryland) as essentially putting the same point about information and quotes him as saying

“'fundamentally a theory about the representation and manipulation of information, not a theory about the mechanics of nonclassical waves or particles'”.

Thus there's a distinction between what is and the information we have about what is. This, again, is simple anti-realism.

Fuchs (as presented by Ball) also makes it explicit that this stress on information is on a par with anti-realism when he argues that it isn't an “ontic” position. It is, instead, “epistemic”. In Ball's words:

“Fuchs sees these insights as a necessary corrective to the way quantum information theory has tended to propagate the notion that information is something objective and real – which is to say, ontic. 'It is amazing how many people talk about information as if it is simply some new kind of objective quantity in physics, like energy, but measured in bits instead of ergs', he says. 'You’ll often hear information spoken of as if it’s a new fluid that physics has only recently taken note of.' In contrast, he argues, what else can information possibly be except an expression of what we think we know?”

I suppose that this means that stuff (as it were) gives off information, rather than stuff being information in and of itself. Yet this conflicts with what some philosophers and physicists see as information. That is, they believe (as Fuchs himself seems to say) that information is in no way mind-dependent. That is, they believe that information is information regardless of minds, persons, observers, experiments, etc. The philosopher John Searle, on the other hand, explicitly puts the information-for-us position. He writes:

“... information is typically relative to observers...These sentences, for example, make sense only relative to our capacity to interpret them. So you can’t explain consciousness by saying it consists of information, because information exists only relative to consciousness.”⁴

It seems, therefore, that in accordance with the quote above, Fuchs is partly at one with Searle on this.

Conclusion

Philip Ball has a problem with what he calls (as already quoted) “the tired old cliches and metaphors” found in talk of quantum mechanics. So let's offer an extreme scenario which also ends with a question:

i) If the mathematics of quantum mechanics fully accounts for what it is physicists are describing,

ii) and we take away the maths,

iii) then what do we have left?

Alternatively, if there is something over and above the maths, then what, exactly, is it? Is that above-and-above remainder accounted for by, say, philosophy? So here again we can state:

i) If the maths is indeed everything

(though many people don't realise that),

ii) then there's a danger of moving from Ball's tired old cliches and metaphors to new cliches and metaphors if we don't realise that.

This, then, may be the only route possible for Ball. However, it leaves the layperson - and even many physicists - will very little to say about quantum mechanics... beyond the mathematics.

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Notes:

1) To state the obvious: the interpretations of quantum mechanics are, well, interpretations. It's hard to grasp what kind of standing a particular interpretation of quantum mechanics could actually have. The very word “interpretation” seems to deflate what it is that's being done – at least from a scientific perspective. Does an interpretation become something else when it is proven or simply established as true or correct? Do any interpretators of quantum mechanics believe that their own interpretations can be proven? What would that mean?

2) In very broad terms, it can easily be argued that there is no “nature of reality” that can exist separately from - as Philip Ball puts it - “our allowed knowledge of it” . Indeed I would even suggest that the “ontic” position hardly makes sense. What does it mean to have a view of reality that is completely divorced from our tools for gaining knowledge of that reality?

3) To sum up. It can be stated in this way:

Ball's “if-isms” = anti-realism

Ball's “is-isms” = metaphysical realism

4) John Searle argues that causes and effects - as well as the systems to which they belong - don't have any information independently of minds. However, that doesn't stop it from being the case that these causes and effects can become information due to direct observations, etc. of them. Searle's position on information can actually be said to be an account of what's called “Shannon information”. This kind of information is “observer-relative information”. In other words, it doesn't exist as information until an observer takes it as information.