Lenin, Rovelli, Materialism and Empirio-Criticism
Rovelli - a scientist in search of a philosophy
Through his articles and books, the Italian theoretical physicist and popular science writer, Carlo Rovelli, has done much to explain modern physics to the wider public. His bestselling paperback ‘Seven Brief Lessons on Physics’, outlining Einstein’s general theory of relativity, quantum mechanics and more besides, has sold over a million copies since it was first published in 2014.
In his 2020 book, ‘Helgoland’, Rovelli decided to focus on his own specialism, quantum theory. The title refers to the name of the island in the North Sea where, in 1925, the young German physicist, Werner Heisenberg, initially conceived some of its key ideas. The first half of the book seeks to explain the mathematical analysis and experimental evidence on which the ‘quantum universe’ of modern physics - and its countless applications, from computers to nuclear energy - are based.
But the universe as described by quantum theory turns out to be a very strange one. That’s why there is also no clear agreement amongst quantum theorists about exactly what ‘quantum reality’ looks like, as Rovelli describes in ‘Helgoland’. A number of different interpretations are outlined in his book, under the labels: ‘Many Worlds’, ‘Hidden Variables’, ‘Physical Collapse’, and ‘QBism’.
“Quantum theory ... has destroyed the image of reality as made up of particles that move along defined trajectories - without, however, clarifying how we should think of the world instead. Its mathematics does not describe reality. Distant objects seem magically connected. Matter is replaced by ghostly waves of probability”.
Carlo Rovelli, ‘Helgoland’, Introduction: ‘Looking into the Abyss’
‘Helgoland’ is Rovelli’s attempt to convince a non-specialist readership of the merits of the particular interpretation of quantum theory that he favours, namely ‘Relational Quantum Mechanics’ or ‘RQM’. The ‘New Scientist’ review of ‘Helgoland” summarises RQM as the contention “that you can go some way to clearing up quantum mysteries by accepting there is no such thing as things, only relations between things”.
“The properties of an object are the way in which it acts upon other objects; reality is this web of interactions. Instead of seeing the physical world as a collection of objects with definite properties, quantum theory invites us to see the physical world as a net of relations. Objects are its nodes.”
Carlo Rovelli, ‘Helgoland’, Chapter III: ‘Relations’
An explanation of the universe that questions whether ‘things’ can really be seen as ‘things’, except when they are interacting with other objects, obviously raises some broader philosophical questions. Rovelli recognises this, explicitly referring to specific thinkers and their philosophies in ‘Helgoland’, particularly in its later chapters.
“Helgoland is all about Rovelli’s attempt to explain perhaps the biggest mystery within quantum physics – what the nature of a reality can be in which, as the theory suggests mathematically at least, things are undefined until we measure them. ‘Is the moon there when nobody looks?’ is one way of expressing the obvious conundrum that arises from that (often attributed to Einstein)”.
New Scientist: ‘Carlo Rovelli’s rebellious past’, June 2021
Rovelli seeks support for his model of quantum reality from the writings of the Buddhist monk Nāgārjuna, from the twentieth century Austrian physicist Ernst Mach, and from the Russian intellectual Alexander Bogdanov, at one time a leading Bolshevik. He adds that the philosophy of Mach “resonates with the ideas of Marx and Engels”. However, he disagrees with Lenin’s philosophy of science, as set out in his book ‘Materialism and Empirio-Criticism’, writing that, in Rovelli’s view at least, Lenin was “an extraordinary politician” but “no great philosopher”.
As a socialist who has spent much of my life teaching physics, I should be grateful that Rovelli has brought Lenin’s writings to the attention of a wider audience. However, sadly Rovelli is also, in my opinion, another name to be added to the long list of writers who have unfairly maligned Lenin and misinterpreted his ideas. In order to correct Rovelli, I have therefore summarised below, in some detail, what I believe Lenin is actually putting forward in ‘Materialism and Empirio-Criticism’.
As I hope that this summary will show, it’s no real surprise that Rovelli disagrees with Lenin. That’s because ‘Materialism and Empirio-Criticism’ is particularly critical of two of the writers that Rovelli has turned to for inspiration: Mach and Bogdanov.
The similarities between their thinking and that of Rovelli also provides good reason to look again at Lenin’s criticisms to see what relevance they might have for today’s philosophical debates about RQM and other interpretations of quantum theory. Rovelli recognises this as well.
“His [Mach’s] most radical suggestion is to stop thinking of phenomena as manifestations of objects and to think, instead, of objects as nodes between phenomena”.
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
Rovelli is able to quote some aspects of the thought of Nāgārjuna, Mach and Bogdanov which, in isolation, could certainly be taken as support for his particular interpretation of quantum theory. However, I think he takes those aspects out of their full original context and fails to sufficiently recognise that other aspects of the philosophies of these three individuals should be highly problematic for any scientist seeking to base their theories on a solid philosophical foundation.
For example, Nāgārjuna, writing in the second century CE, believed that the mind was ‘immaterial’ and, as such, the objects we can perceive with our mind must be ultimately immaterial too. Is that any basis for modern science? The idea that Mach and Bogdanov’s philosophy had a sound basis in Marxism would also be disputed by most genuine Marxists. Indeed, the fact that it did not genuinely reflect a Marxist, ‘dialectical materialist’ outlook was one of the key points that Lenin was seeking to make in ‘Materialism and Empirio-Criticism’.
However, to Rovelli’s credit, he is seeking answers, including amongst the writings of Marx, Engels and Lenin. Rovelli recognises that philosophy is important. He correctly understands that how a person thinks more generally about the world will provide them with a foundation for the more specific conclusions that they will reach, whether in science or in politics.
However, to me, Rovelli’s musings on philosophy are far less convincing than his scientific writing. In fact, they open him up to the counter-claim, aimed by Lenin in ‘Materialism and Empirio-Criticism’ at the renowned physicist Poincaré, that Rovelli is ‘an eminent physicist but a poor philosopher”!
However, before discussing philosophy in more detail, then, just as Rovelli does in ‘Helgoland’, it’s best to start with a quick review of the relevant science. Before looking at quantum theory in more detail, it’s useful to first summarise the contributions made to modern physics by Albert Einstein.
Einstein sets out a revolution in physics
In 1905, the then unknown Einstein had submitted four separate papers that each set out significant new advances in our understanding of physical reality. His first paper, on the ‘photoelectric effect’, showing that light consists of what became known as ‘photons’, formed the basis of quantum theory.
“Einstein ... wrote, in the introduction to his article: ‘It seems to me that observations associated with blackbody radiation, fluorescence, the production of cathode rays by ultraviolet light, and other related phenomena connected with the emission or transformation of light are more readily understood if one assumes that the energy of light is discontinuously distributed in space.
In accordance with the assumption to be considered here, the energy of a light ray spreading out from a point source is not continuously distributed over an increasing space but consists of a finite number of “energy quanta” which are localised at points in space, which move without dividing, and which can only be produced and absorbed as complete units’.
These simple and clear lines are the real birth certificate of quantum theory”.
Carlo Rovelli, ‘Seven Brief Lessons in Physics’, Second Lesson: ‘Quanta'
The second paper, on ‘Brownian Motion’, provided clear evidence for the physical existence of atoms. The third paper set out his ‘special theory of relativity’. This theory confirmed that our everyday ‘common sense’ understanding of space and time has to be adjusted in the ‘special case’ of objects moving at high relative velocities. The theory incorporated the mathematical formulas previously proposed by the Dutch physicist Hendrik Lorentz (still named today as the ‘Lorentz transformations’) that showed that moving objects contract in length in their direction of motion, but that this ‘length contraction’ effect is only noticeable when they are moving close to the speed of light.
Einstein showed that another consequence of special relativity is ‘time dilation’ - that how quickly time passes is dependent on relative velocity as well (an odd idea, but one later confirmed by experiment). This led to physicists combining the three dimensions of space with the single dimension of time and making relativistic calculations in ‘four-dimensional spacetime’.
Einstein’s special relativity also successfully resolved one of the main scientific debates of his time. Up until then, scientists had believed that the universe must be filled which an as yet undetected substance, the ‘ether’. This was needed to explain how light and radio waves were able to travel through otherwise empty space. Sensitive experimental apparatus, such as the ‘Michelson-Morley interferometer’, had been devised to see if the Earth’s relative motion through that ether could be detected. However, it had failed to do so. Special relativity was able to explain this ‘null result’ and, along with Einstein’s proposal of ‘quantised’ light [later to be known as ‘photons’], why the concept of an ‘ether’ was therefore unnecessary.
His final paper, a supplement to the one on special relativity, showed how mass and energy could be considered as being one and the same entity – a concept known as ‘mass-energy equivalence’ – described mathematically through his now famous “E=mc^2” equation.
In a short 2015 article in the ‘Independent’, extracted from his ‘Seven Brief Lessons in Physics’, Rovelli explains how “Einstein became a renowned scientist overnight and received offers of employment from various universities. But something disturbed him: despite its immediate acclaim, his theory of relativity did not fit with what we know about gravity – namely, with how things fall”.
"Newton had tried to explain why things fall and planets turn. He had imagined the existence of a ‘force’ which draws all material bodies towards one another, and called it ‘the force of gravity’. How this force was exerted between things distant from each other, without there being anything between them, was unknown ... Newton also imagined that bodies moved through space, and that space was a great empty container, a large box which enclosed the universe, an immense structure through which all objects ran true until a force obliged their trajectory to curve. What this ‘space’ was made of, this container of the world he invented, Newton could not say”.
Carlo Rovelli, ‘Seven Brief Lessons in Physics’, First Lesson: ‘The most beautiful of theories’
In 1915, Einstein published his answer - his general theory of relativity. Rovelli has rightly described Einstein’s general theory of relativity as “a masterpiece of elegance and simplicity. It predicts incredible yet true facts: curvature of space-time, black holes, the Big Bang, and the expansion of the universe”. [‘La fisica in tre puntate’].
“Space is no longer something distinct from matter, it is one of the ‘material' components of the world. An entity that undulates, flexes, curves, twists. We are not contained within an invisible, rigid infrastructure: we are immersed in a gigantic, flexible snail shell.
The sun bends space around itself, and the Earth does not turn around it because of a mysterious force but because it is racing directly in a space which inclines, like a marble that rolls in a funnel. There are no mysterious forces generated at the centre of the funnel; it is the curved nature of the walls which causes the marble to roll. Planets circle around the sun, and things fall, because space curves."
Carlo Rovelli, ‘Seven Brief Lessons in Physics’, First Lesson: ‘The most beautiful of theories’
Einstein had tried to work out how Faraday and Maxwell’s work on electromagnetism - which proposed that light and radio waves were transferred via a space-filling ‘electromagnetic field’ - could be applied to gravitational forces. But, Rovelli explains, "at this point ... an extraordinary idea occurred to him, a stroke of pure genius: the gravitational field is not diffused through space; the gravitational field is that space itself. This is the idea of the theory of general relativity. Newton's ‘space’, through which things move, and the ‘gravitational field’ are one and the same” [‘Seven Brief Lessons in Physics’].
General Relativity was soon tested in practice, and found to correctly predict how light rays from a distant star change course as they pass through the curved space around our Sun, just like the ball from an unlucky golf putt curves around the lip of a hole.
The theory also explains why clocks that are positioned in a weaker part of a gravitational field appear to run faster than those where gravity is stronger. This, again, is not just theory, an adjustment has to be made in practice in order for GPS devices to work properly. This is because, as predicted by Einstein’s theories, clocks run slightly faster on the GPS satellites than on the Earth’s surface.
General Relativity also made predictions about the universe as a whole which, once again, have been confirmed in practice. It predicted both the now well-evidenced existence of “black holes” as well as the fact that our universe should be expanding from a “Big Bang” – an idea that is also now backed up by a range of experimental observations.
Quantum Theory
Alongside General Relativity, the second main pillar of today’s theoretical physics is ‘quantum theory’. In summary, this is the idea that, observed at close quarters, the world around us is ‘granular’, rather than ‘continuous’.
In ‘Helgoland’, Rovelli tells the story of how these ideas arose. Their origins start with observations that suggested that some physical quantities, such as the energy and frequency of the ‘black body radiation’ emitted by a hot oven, could only take certain fixed values. The spectrum of emitted radiation could only be fully explained if its energy was being transmitted in discrete packets or ‘quanta’.
As early as 1900, the German physicist Max Planck proposed that the energy of each quantum (or, nowadays, ‘photon’) was proportional to the frequency of the radiation. As described above, Einstein’s first 1905 paper extended this idea to explain why the electric current generated by the ‘photoelectric effect’ depended on both the frequency and the intensity of light shone onto a metal.
In 1924, the French theorist, Louis de Broglie, went further and suggested that all particles could be treated as being waves as well – a concept known as ‘wave particle duality’. Experiments showing that a beam of electrons could be diffracted - like a beam of light - confirmed that electrons could indeed behave as both a particle (with a particular energy) and as a wave (with a corresponding frequency).
A different strand of the development of quantum theory had begun with the Danish physicist Niels Bohr. In 1911, Bohr had been invited to England to work with other physicists researching the structure of atoms, including the New Zealander, Ernest Rutherford. In that year Rutherford had proposed his ‘nuclear model’ of the atom. This was based on his analysis of the results of Geiger and Marsden's 'alpha-particle scattering experiments’ which had showed that the atom’s positive charge must be concentrated in a small central 'nucleus'.
Bohr returned to Denmark, concentrating on developing a model of the atom where the negative electrons orbited around the positive central nucleus. Bohr was not the first to suggest such a ‘planetary model’ of the atom but Rovelli explains that he was the first to propose: “that the electrons in atoms orbited around the nucleus only on certain precise orbits, at certain precise distances from the nucleus, with certain precise energies - before magically ‘leaping' from one orbit to another. The first quantum leaps” [‘Helgoland’].
By proposing these ‘quantised’ orbits, where only certain fixed energies were allowed, Bohr’s model successfully explained the different colours of light emitted by chemical elements when they were heated. But why only these energy levels? This was the problem that Heisenberg, invited by Bohr to be part of his research team in Copenhagen, was determined to resolve.
Thinking through the problem while on Helgoland in 1925, Heisenberg came up with mathematical formulas based on ‘matrices’ – tables of numbers that corresponded to the various ‘quantum leaps’ observed in the emission spectrum of the simplest element, hydrogen. After some initial frustration, the ‘matrix mechanics’ started to produce meaningful outcomes.
Rovelli writes [in ‘Helgoland’] that: Heisenberg “sends a copy of his results to his friend [Wolfgang] Pauli, with the comment that 'everything is still vague and unclear to me, but it seems that electrons no longer move in orbits'.” History shows that Heisenberg had indeed drafted the foundation of today’s quantum mechanics, including modern chemistry’s atomic model where electrons are located somewhere within a range of differently shaped ‘atomic orbitals’ instead of defined ‘orbits’.
“When the first terms seemed to come right, I became excited, making one mathematical error after another. As a consequence, it was around three o'clock in the morning when the result of my calculations lay before me. It was correct in all terms. Suddenly I no longer had any doubts about the consistency of the new 'quantum' mechanics that my calculation described.
At first, I was deeply alarmed. I had the feeling that I had gone beyond the surface of things and was beginning to see a strangely beautiful interior, and felt dizzy at the thought that now I had to investigate this wealth of mathematical structures that Nature had so generously spread out before me”.
Werner Heisenberg quoted by Carlo Rovelli in ‘Helgoland’
Rovelli continues: “Heisenberg tries to get Pauli involved, but Pauli is unconvinced: it all seems to him like a mathematical game, far too abstract and abstruse”. However, despite his initial scepticism, Pauli then applied his skills to the complexity of matrix mathematics and helped Heisenberg to perfect his quantum mechanical model of the hydrogen atom.
However, those mathematical models began to get even more ‘abstruse’ when the Austrian physicist, Erwin Schrödinger, started to combine the ideas of Heisenberg and his co-thinkers with those of de Broglie. This led Schrödinger to propose the key concept of the ‘wave function’.
“Schrödinger is captivated by the idea that the trajectories of elementary particles are also approximations of the behaviour of an underlying wave ... In naming his wave, Schrödinger uses the Greek letter psi ... also called the ‘wave function’ ... His fabulous calculation seems to show clearly that the microscopic world is not made up of particles: it is made up of psi waves”.
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Misleading Psi of Erwin Schrödinger: Probability’
But how can Schrödinger’s wave functions provide a real model of reality? After all, when an electron is detected, it isn’t spread out like a wave would be, but observed as an actual particle with a small but measurable mass. Rovelli explains that the solution proposed by quantum physicists to resolve this paradox was to say that the size of the wave function at any point gives you the probability of finding the corresponding particle there. So, based on this interpretation, quantum theory proposes a sub-atomic world where probabilities replace the precise predictions of ‘classical’ physics.
“The value of Schrödinger's psi wave at a point in space is related to the probability of observing the electron at this point. If an atom emits an electron and is surrounded by particle detectors, the value of psi where there is a detector determines the probability of that detector and not another detecting the electron”.
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Misleading Psi of Erwin Schrödinger: Probability’
But that’s not all. Heisenberg’s mathematical models also generated his famous ‘uncertainty principle’ which asserts that our knowledge of the fine details of the universe will always be imprecise. It basically states (avoiding using mathematical notation) that if you measure the position of an object precisely, then there will inevitably be a limit as to how precisely you can then also measure its speed (or to be more accurate, its ‘momentum’).
In everyday life, the objects we interact with are too big for this uncertainty to be an issue but, when considering tiny sub-atomic particles, the ‘uncertainty principle’ says that’s no longer the case. The defined ‘cause-and-effect’ of classical physics is replaced by a quantum physics which is essentially indeterministic.
“When we observe the world at our scale we do not see its granularity. ... With many variables, fluctuations become irrelevant, and probability nears certainty. Billions of discontinuous events of the agitated and fluctuating quantum world are reduced by us to the few continuous and well-defined variables of our everyday experience.
At our scale, the world is like the wave-agitated surface of the ocean seen from the moon: the smooth surface of a blue marble ... but at the molecular scale, the cutting edge of a sharp knife is as fluctuating and imprecise as the edge of an ocean in a storm, fraying upon the white sand of its shore”.
Carlo Rovelli, ‘Helgoland’, Chapter IV: ‘Information’
However, like Einstein’s relativity, quantum mechanics has turned out to be more than just a quirky mathematical model of the subatomic world. The theory has been tested in practice and applied successfully in many different ways.
“With his consent, Bohr is kidnapped in a British commando raid and taken out of occupied Denmark. He is taken to England and ... then to the United States, where his knowledge is put to work with the generation of young physicists who have learned how to use the new quantum theory to manipulate atoms. Hiroshima and Nagasaki are annihilated.
Thankfully, there is much more than weapons. Quantum theory has been applied to atoms, atomic nuclei, elementary particles, the physics of chemical bonds, the physics of solid materials, of liquid and gas, semiconductors, lasers, the physics of stars such as the Sun, neutron stars, the primordial universe, the physics of the formation of galaxies.
... Quantum theory has allowed us to understand whole areas of nature, from the form of the periodic table of elements to medical applications that have saved millions of lives. It has predicted new phenomena never previously imagined: quantum correlations over a distance of kilometres, quantum computers, [quantum] teleportation ... all predictions have turned out to be correct.”
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Absurd Idea of the Young Heisenberg: Observables’
Probability and Observation – Quantum Physics and Philosophy
So quantum theory had certainly helped to explain phenomena that were unable to be explained by earlier ‘classical’ physics. But it doesn’t explain the nature of the universe itself.
“Schrödinger's psi is ... not a representation of a real entity: it is an instrument of calculation that gives the probability that something real will occur. It is like the weather forecasts telling us what could happen tomorrow ... Quantum theory, just as much in Heisenberg's version as in Schrödinger's, predicts probability, and not certainty”.
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Misleading Psi of Erwin Schrödinger: Probability’
Some scientists, such as Einstein and Schrödinger, wanted to go further. They wanted science to be able to explain the nature of the reality that existed behind the wave functions. But Niels Bohr's philosophy was very different. In his article in the 1963 ‘Bulletin of the Atomic Scientists’, a colleague of Bohr, Aage Petersen, wrote that: “When asked whether the algorism [arithmetic] of quantum mechanics could be considered as somehow mirroring an underlying quantum world, Bohr would answer, ‘There is no quantum world. There is only an abstract quantum physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.’ ”
So Bohr, who set the philosophical tone for the way quantum theory should be interpreted, ruled out any idea that science should – or even could – try to describe the nature of actual reality underlying quantum theory. For Bohr, all that mattered was that the theory was able to explain what scientists were able to observe through experimental investigation. Beyond that, Bohr insisted, physics could go no further. After all, wave functions themselves were unobservable mathematical constructs.
In ‘Helgoland’, Rovelli notes that Bohr’s outlook was influenced by the ‘positivist’ philosophy of Ernst Mach, Pauli’s godfather, who “insisted that knowledge had to be based solely on observations, freed of any ‘metaphysical’ assumption’ ”. (Lenin’s criticisms of Mach's views, as set out in ‘Materialism and Empirio-Criticism’, are discussed below).
Bohr’s philosophy became the generally accepted understanding of how quantum theory operated, part of what became known as the ‘Copenhagen Interpretation’. Under this interpretation, until we observe an object, it isn’t possible to describe the exact path any particle takes, but only to describe its wave function. As Heisenberg put it, “the path comes into existence when we observe it (Die ‘Bahn’ entsteht erst dadurch, dass wir sie beobachten)”.
In other words, it’s the act of observation that triggers a collapse of the probabilistic wave function which had been previously spread out in space. Only then does it become the particle we observe, situated in one particular position.
“Schrödinger's psi wave is definitely not sufficient to clarify the obscurity of the quanta. It is not enough to think of the electron as a wave. The psi wave is something unclear, which determines the probability that the electron will be observed in one place rather than in another. It evolves in time according to the equation written by Schrödinger, as long as we do not look at it. When we look at it, pttf!, it disappears, concentrated into a point, and we see the particle there”.
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Misleading Psi of Erwin Schrödinger: Probability’
Such a ‘subjective’ outlook on reality inevitably raises important philosophical questions. For example, as “the information philosopher” [a useful website although one that has its own particular ‘information philosophy’ outlook] puts it “Does the collapse only occur when an observer ‘looks at’ the system?” Or even, as the nuclear physicist Eugene Wigner effectively claimed, “Does the mind of the observer have causal power over the physical world?”.
The same source makes clear that most physicists would argue against the idea that such a ‘conscious observer’, a being with a thinking mind, is required to ‘collapse the wave function’. They would argue that what’s required is some kind of interaction with another system, but that certainly doesn’t need to be an observation made by a conscious human being. But, nevertheless, in the language of philosophy, according to the ‘Copenhagen interpretation’ at least, “physics required a subjective view [which is therefore] unable to reach the objective nature of the ‘things in themselves’.”
The ‘thing-in-itself’, a term introduced into philosophy by Immanuel Kant, refers to actual objective reality, independent of our subjective interpretation and observation of the world. It is a term that Marx and Engels would have been familiar with and, as discussed below, is referred to by Lenin in ‘Materialism and Empirio-Criticism’.
Heisenberg doesn’t use the term explicitly in his explanation of the ‘Copenhagen Interpretation’ but does make clear that he agrees that quantum physics inevitably has a “subjective element” since “what we observe is not nature in itself [i.e. ‘the thing-in-itself’] but nature exposed to our method of questioning”.
“This again emphasises a subjective element in the description of atomic events, since the measuring device has been constructed by the observer, and we have to remember that what we observe is not nature in itself but nature exposed to our method of questioning. Our scientific work in physics consists in asking questions about nature in the language that we possess and trying to get an answer from experiment by the means that are at our disposal”.
Werner Heisenberg, ‘The Copenhagen Interpretation of Quantum Mechanics’, 1955.
Perhaps the best known example of the apparently ‘subjective’ nature of the world, as revealed by quantum theory, are the strange results provided by so-called ‘double slit experiments’. These had always been a staple part of any ‘classical physics’ course explaining the behaviour of waves. The ‘crests’ and ‘troughs’ of light waves emerging through two thin slits combine with each other to form a characteristic ‘interference pattern’ of dark and bright bands on a screen positioned beyond those slits.
But quantum physicists wondered whether the same behaviour could be demonstrated with a wave function. In particular, if the wave function of, say, a photon or electron was similarly passed through two slits, would the two separated wavelets ‘interfere’ with themselves and form the same kind of fringe pattern? At first, the idea was just a ‘thought experiment’ used to discuss the implications of quantum theory but, once the sensitive experimental apparatus required had been developed, it became possible to test theory in practice.
In ‘Helgoland’, Rovelli describes the results of one version of such an experiment, using photons from laser beams. Just as you would expect if the wave function indeed behaves like a wave, when the laser is split into two separate paths and then recombined, ‘interference’ occurs. However, ( and this takes some thinking about! ), if you use a detector to try and measure which of the two paths the photon has actually taken, the interference disappears!
The “information philosopher” website (which also includes some useful explanatory animations) gives this explanation of the reason for the observed interference: “The particle always goes through a single slit. A particle cannot be divided and in two places at the same time. It is the wave function that interferes with itself”.
However, it adds an important rider pointing to the ‘mystery’ yet to be solved by quantum theorists and philosophers alike: “The two-slit experiment also demonstrates the inherent probabilistic element in quantum mechanics ... This is the deepest metaphysical mystery ... . How can an abstract probability wave influence the particle paths to show interference when large numbers of particles are collected?”
“Each photon passes (entire) on the left, or (entire) on the right. Each photon behaves as if it passed through both trajectories, as waves do (otherwise there would be no interference), but if we look to see where the photon is, we always see it on just one path ... The very act of measuring which path the photon takes causes the interference to disappear! ... If you observe where a photon passes, its psi wave jumps entirely on to a path ... there is no longer interference. The wave function ‘collapses’ .... converging in one point, the moment we observe it”.
Carlo Rovelli, ‘Helgoland’, Chapter II: ‘Superpositions’
Einstein and Schrödinger question Bohr’s philosophy
Albert Einstein’s early work on both statistics and the photoelectric effect had helped to launch quantum theory. Erwin Schrödinger’s work on wave functions was key to its description of the quantum universe. Yet both scientists, although from different perspectives, were far from convinced by the interpretation that Bohr, Heisenberg and his co-thinkers had reached. Both believed that science should seek to describe the nature of underlying reality, not argue that it was impossible to do so.
Schrödinger opposed the way that Bohr and others had decided that the wave functions he had devised should be interpreted as describing just probabilities. He came up with his well-known ‘Schrödinger’s Cat’ paradox as a ‘thought experiment’ designed to discredit their approach. The details of the paradox, and the detailed reasoning that different theorists provide to resolve it, would fill many pages. However, in brief, Schrödinger argued that a probabilistic interpretation of wave functions would allow a nonsensical situation to exist where a cat could be, rather like the two paths potentially taken by photons in a two-slit experiment, both ‘dead’ and ‘alive’ at the same time. (Rovelli's ‘RQM’ has its own solution to the paradox, which I will return to later).
In order to expose what he also saw as flaws in the ‘Copenhagen Interpretation’, Einstein came up with a series of rather more sophisticated ‘thought experiments’. As Rovelli explains in ‘Helgoland’, these formed part of “a famous debate ... between Einstein and Bohr [that] went on for years through personal encounters, conferences, written works, letters ... .”
The details of those debates can be read about in greater detail on a range of websites but some of Einstein’s own argumentation can be read online in his 1949 “Reply to Criticisms”. In this article, Einstein argues that the correctness of Heisenberg’s ‘uncertainty principle’ doesn’t mean that scientists have to accept that only an uncertain, indeterministic model of reality can ever be constructed. Furthermore, he doesn’t accept that the probabilistic model put forward under the ‘Copenhagen Interpretation’ offers a “theoretically complete description” of the universe.
In short, Einstein recognised quantum theory as a step forward in scientific understanding but one that was still far from complete. It provided a statistical, probabilistic model that could explain the behaviour, on average, of a collection of particles but could not yet describe the behaviour or nature of individual particles. Einstein viewed quantum mechanics as a theory that, for now, was simply the best science could do - but, in future, it needed to do better.
“My highly esteemed colleagues Born, Pauli, Heitler, Bohr, and Margenau ... are all firmly convinced that the riddle of the double nature of all corpuscles (corpuscular [particle-like] and undulatory [wave-like] character) has in essence found its final solution in the statistical quantum theory. On the strength of the successes of this theory they consider it proved that a theoretically complete description of a system can, in essence, involve only statistical assertions concerning the measurable quantities of this system. They are apparently all of the opinion that Heisenberg’s indeterminacy-relation (the correctness of which is, from my own point of view, rightfully regarded as finally demonstrated) is essentially prejudicial in favour of the character of all thinkable reasonable physical theories in the mentioned sense. In what follows I wish to adduce reasons which keep me from falling in line with the opinion of almost all contemporary theoretical physicists”.
“I am, in fact, firmly convinced that the essentially statistical character of contemporary quantum theory is solely to be ascribed to the fact that this [theory] operates with an incomplete description of physical systems ... Within the framework of statistical quantum theory there is no such thing as a complete description of the individual system”.
Albert Einstein, ‘Reply to Criticisms’, 1949.
A useful summary (although scientifically technical in parts) of Einstein’s scientific arguments with Bohr can be read on John D. Norton’s web page “Einstein on the Completeness of Quantum Theory”. Norton explains how subsequent experiments have shown that Einstein got some of his arguments wrong (in particular, his objections relating to the strange quantum phenomenon of ‘entanglement’). On the other hand, Norton also points out the lack of clarity in some of Bohr’s opaque argumentation, the understanding of which, as Einstein witheringly put it, “I have been unable to achieve despite much effort which I have expended on it” (!).
So, while some of the details of Einstein’s objections have been answered by subsequent evidence, his concerns should not be lightly dismissed. It’s worth noting that Norton, a Professor of History and Philosophy of Science in the United States, agrees that the lack of clarity about the ‘measurement problem’ - that is the lack of agreement on how, or whether, ‘wave function collapse’ actually occurs in reality - means that “there is something quite unresolved in the foundations of quantum theory”.
“In my view, [Einstein] was not wrong to resist the foundational accounts that surrounded quantum theory in his final decades. He was quite right to protest that no account of the quantum domain could so glibly give up the notion of reality as they did. All was not well then in our accounts of the quantum domain; and all is not well now. The clearest indication of the trouble is the persistence of the measurement problem. It shows us that there is something quite unresolved in the foundations of quantum theory”.
John D. Norton on the ‘Einstein-Bohr Debate’
As for Rovelli, ‘Helgoland’ summarises the debate between Einstein and Bohr with an exchange that reputedly took place between the two scientists: “Einstein put the question colourfully ... despite his declared atheism ... ‘Does God play dice?’ [meaning] literally ‘Are the laws of Nature really not deterministic?’ ... Bohr responded by admonishing him to ‘Stop telling God what to do.’ Which means: Nature is richer than our metaphysical prejudices. It has more imagination than we do’ ”.
Rovelli’s writings suggest that he would take Bohr’s side of the argument. In other words, Rovelli seems to agree that, if you insist that there is a fully objective reality to the universe around us, you are asserting a prejudiced “metaphysical” philosophical outlook. Einstein’s writings make clear that this accusation of “metaphysical prejudice” was, indeed, exactly the one levelled at him by his opponents. As we shall see below, the same charge was also being levelled at Marxists in Lenin’s time too!
“What does not satisfy me in [quantum] theory, from the standpoint of principle, is its attitude towards that which appears to me to be the programmatic aim of all physics: the complete description of any (individual) real situation (as it supposedly exists irrespective of any act of observation or substantiation). Whenever the positivistically inclined modern physicist hears such a formulation his reaction is that of a pitying smile. He says to himself: ‘there we have the naked formulation of a metaphysical prejudice, empty of content, a prejudice, moreover, the conquest of which constitutes the major epistemological achievement of physicists within the last quarter-century. Has any man ever perceived a ‘real physical situation’? ”.
Albert Einstein, ‘Reply to Criticisms’, 1949.
This is the philosophical context in which Rovelli’s criticisms of Lenin’s book ‘Materialism and Empirio-Criticism’ must be read.
Rovelli reads - but disagrees with - Lenin
Lenin’s book had been written before Bohr debated with Einstein, and certainly well before Rovelli expressed his own philosophical views. However, Lenin’s writings show that, while scientific knowledge and theories may have since advanced, essentially the same clash of philosophical ideas was taking place back in 1909. This was the year when ‘Materialism and Empirio-Criticism’ was published, setting out Lenin’s analysis of the varying philosophical trends underlying the scientific literature on theoretical physics available to him that time.
Lenin’s book takes particular aim at what was, at the time, the fashionable philosophy of ‘Empirio-Criticism’. This was a way of thinking that had been set out by Ernst Mach and then adapted by Aleksandr Bogdanov under the label of ‘Empirio-Monism’.
Rovelli, in his search for past ideas that might help inform today’s debates on the nature of ‘quantum reality’, also recognises that “the issues debated by Lenin and Bogdanov have returned in contemporary philosophy.” He is impressed that Lenin should be so well versed in science and philosophy, but disagrees with Lenin’s conclusions.
He argues that Lenin was wrong to attack the ideas of Mach and Bogdanov, and claims that Lenin wrongly accuses them of being ‘idealists’. [In the philosophical sense of the word, explained by Rovelli in ‘Helgoland’ as follows: “An idealist, for Lenin, negates the existence of a real world beyond the spirit and reduces reality to the content of consciousness”].
He defends Mach and Bogdanov against such criticism, countering that Lenin held an overly simplistic and outdated view of ‘materialism’, one that insisted that the nature of reality had to be “matter in motion”. Rovelli indicates that he broadly supports their philosophy and believes that their ideas help to explain the conclusions reached by Bohr, Heisenberg and other quantum theorists.
“Lenin’s critique of Mach and Bogdanov’s reply interests us here. Not because Lenin is Lenin, but because his criticism is the natural reaction to the ideas that led to quantum theory. ... Precisely the issues debated by Lenin and Bogdanov have returned in contemporary philosophy. Their discussion provides a key for understanding the revolutionary significance of quanta. ...
Whatever we think about communism, there is no denying that Lenin was an extraordinary politician. His knowledge of philosophy and science is also impressive; if today we elected politicians as cultivated as Lenin, perhaps they would be more effective. But Lenin was no great philosopher. The influence of his philosophical thought is due more to his long dominance of the political scene and his elevation to heroic status under Stalin than to the profundity of his arguments. ...
For Lenin, the only acceptable version of materialism is the idea that 'there is nothing in the world except matter in motion in space and in time’ and that we can arrive at ‘certain truths’ through knowledge of matter”.
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
Rovelli also writes in favour of Bogdanov’s political philosophy against that of Lenin, supporting Bogdanov's criticisms of Lenin’s alleged ideological and political ‘dogmatism’. Rovelli also refers supportively to Bogdanov’s leading role in developing the idea of ‘proletarian culture’, a political outlook that was criticised by both Lenin and Trotsky.
“Even more impressive is Bogdanov’s political reply to Lenin. Lenin speaks of absolute certainties. He presents the historical materialism of Marx and Engels as if it were timelessly valid. Bogdanov points out that this ideological dogmatism not only fails to accord with the dynamic of scientific thought, it also leads to calcified political dogmatism.
The Russian Revolution, Bogdanov argues in the turbulent years of its aftermath, had created a new economic structure. If, as Marx suggested, culture is influenced by economic structure, then post-revolutionary society would be able to produce a new culture that could no longer be the orthodox Marxism conceived before the Revolution. Brilliant. Bogdanov's political programme was to leave power and culture to the people, to nurture the new, collective, generous culture opened up by the revolutionary dream. Lenin's political programme, instead, was to reinforce the revolutionary avant-garde, the repository of truth that needed to guide the people. ...
Bogdanov predicts that Lenin’s dogmatism will seal the Russian Revolution into a block of ice; prevent it from evolving further; suffocate the life out of all that had been gained through it; render it sclerotic. These, too, were prophetic words”.
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
Socialists with an understanding of the actual developments of the Russian Revolution might well quickly conclude that Rovelli may have a good understanding of quantum mechanics but not such a good grasp of Marxism. Instead of analysing the history of Bolshevism objectively, it is Rovelli that has allowed his ‘prejudices’ to affect his conclusions. He clearly does not appreciate why the idea of ‘proletarian culture’ was mistaken, as summarised in the quoted article by Trotsky, nor has he understood the gulf that separated Lenin’s thought from the falsified version of it that emerged through Stalinism.
“Here is a recent example, one of a hundred, where a slovenly, uncritical and dangerous use of the term ‘proletarian culture’ is made. ‘The economic basis and its corresponding system of superstructures,’ writes Sizoy, ‘form the cultural characteristics of an epoch (feudal, bourgeois or proletarian).’ Thus the epoch of proletarian culture is placed here on the same plane as that of the bourgeois. But that which is here called the proletarian epoch is only a brief transition from one social-cultural system to another, from capitalism to socialism. ... The length of this period depends entirely upon the success of the revolution. Is it not amazing that one can forget this and place the proletarian cultural epoch on the same plane with that of feudal and bourgeois culture?”
“As the new regime will be more and more protected from political and military surprises and as the conditions for cultural creation will become more favourable, the proletariat will be more and more dissolved into a socialist community and will free itself from its class characteristics and thus cease to be a proletariat. In other words, there can be no question of the creation of a new culture, that is, of construction on a large historic scale ... there is no proletarian culture and that there never will be any and in fact there is no reason to regret this. The proletariat acquires power for the purpose of doing away forever with class culture and to make way for human culture. We frequently seem to forget this”.
Leon Trotsky, ‘What Is Proletarian Culture, and Is It Possible?’, 1923.
However, as Rovelli undoubtedly knows his physics, ‘Helgoland’ clearly raises an interesting question about how well Lenin’s 1909 writings on science have stood the test of time in the light of today’s scientific knowledge. More significantly, since any scientific writing from this period is inevitably going to be dated, does Rovelli’s criticism of Lenin’s overall philosophical outlook – and his support for Mach and Bogdanov’s – really help inform today’s scientific understanding of the nature of matter, time and space?
Lenin’s critique of ‘Empirio-Criticism’
Lenin’s book, polemical in style, is not a particularly easy read. It was written in opposition to the philosophical claims of Mach, Bogdanov, and similar ‘Empirio-Criticists’. However, Bogdanov was, at the time, also a Bolshevik. So, by implication, since a person’s philosophical outlook also conditions their political outlook, the book was aimed at opposing Bogdanov’s political programme too.
It was being written at a time when, following the defeat of the 1905 Russian Revolution, Lenin saw the need to patiently rebuild the revolutionary workers’ movement. He was strongly opposed to Bogdanov’s faction of ‘Otzovists’ (or ‘Recallists’) who supported a mistaken ‘ultra-left’ strategy. The Otzovists argued against participation in the limited ‘legal’ avenues then open to the Russian Social Democratic Labour Party, in particular demanding the RSDLP representatives withdrew from the State Duma (Parliament).
However, it would be wrong to see ‘Materialism and Empirio-Criticism’ as being chiefly a couched political attack on Bogdanov. It is, first and foremost, a carefully researched document based on nine months of detailed study of the latest scientific literature of the time.
The book is necessarily commenting on the scientific debates, and using the scientific language, of that particular historical period. Moreover, many of the specifics of those debates can now be hard to follow as we no longer use the scientific models that were current at that time. For example, Lenin refers to the ‘ether’, then generally accepted by physicists as a medium filling all space, required to allow light and other electromagnetic waves to travel. This had proved a useful concept at the time, and Maxwell’s ground-breaking electromagnetic equations were based on it. However, as discussed above, subsequent experimental evidence and Einstein’s alternative theoretical explanations rendered this concept redundant.
Lenin’s preparatory research was carried out in 1908. Rutherford would only propose his nuclear model of the atom in 1911; Einstein would not publish his paper on general relativity until 1915; Bohr, Heisenberg and Schrödinger would not develop quantum mechanics until the 1920s. So, although the book mentions physicists whose names are still associated with currently accepted physics, such as Helmholtz, Boltzmann, Thomson, Lorentz, Maxwell - and Mach himself - the context in which these scientists were then developing their theories was not the same as it would be under currently accepted physics. Lenin’s scientific conclusions also have to be read in this historical context.
Unfortunately, as with so much of Lenin’s writings, ‘Materialism and Empirio-Criticism’ was subject to exactly such misreading by the Stalinist writers who falsely claimed to be following genuine Marxist ideas. Phrases within it were taken as showing that Lenin would have opposed both general relativity and quantum theory.
As one well-informed study of science in the Soviet Union explains, this dogmatic Stalinist falsification of science became particularly prevalent “in the late forties and early fifties ... from third-rate scientists who tried to win Stalin's favour”. These “unprincipled careerists” included not only the notorious Lysenko (in the field of genetics) but also physicists like Maksimov. Supposedly in the name of ‘Marxism-Leninism’, Maksimov not only opposed ‘reactionary Einsteinism’ but even rejected the simplest concepts of relativity that had been universally accepted since the time of Galileo! As I will try to explain below, any such false conclusions can only be arrived through a total misinterpretation of Lenin’s methods and of Marxist dialectical materialism.
Lenin also clarified some of his philosophical views in later years, although, with more pressing revolutionary events having to be prioritised (!), never in the same detail as in ‘Materialism and Empirio-Criticism’. I make a reference below to a note Lenin made in his personal “Philosophical Notebooks” which usefully expands on a point that Lenin had made in his earlier book.
With those warnings noted, then I believe that ‘Materialism and Empirio-Criticism’ still has much to offer in terms of the philosophical approach that Marxists should apply to objective reality – and to today’s scientists seeking to clarify the exact nature of that reality. I also think it shows Rovelli’s criticisms to be misplaced.
What is reality? - Materialism vs. Idealism
If there is one clear thread running through Lenin’s book, it is his insistence that there are two distinct but contrasting trends in philosophy – materialism and idealism.
Lenin explains that, as human beings, we of course find out about the world around us through our senses – on that both an idealist and materialist would agree. But Lenin argues that a materialist believes that our senses give us an ‘image’, if not always a perfect one, of a real objective world that exists around us. An idealist outlook believes that thoughts and sensations are primary, that they are the only ‘reality’ we perceive, rather than (as is understood by a materialist outlook) there being a real world that continues to exist around us, whether or not we are sensing it.
“All knowledge comes from experience, from sensation, from perception. That is true. But the question arises, does objective reality “belong to perception,” i.e., is it the source of perception? If you answer yes, you are a materialist”. ...
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
“Idealist philosophy ... regards sensation as being not the connection between consciousness and the external world, but a fence, a wall, separating consciousness from the external world - not an image of the external phenomenon corresponding to the sensation, but as the ‘sole entity.’”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter One: ‘1. Sensations & Complexes of Sensations’
In short, quoting the philosopher Feuerbach, Lenin describes a materialist outlook as recognising that “my sensation is subjective, but its foundation is objective”. And Lenin is adamant that such a fundamental philosophical divide - between materialism and idealism – can’t be written off as a distinction that has suddenly lost its relevance.
Lenin demands absolute consistency on this question, on accepting “the objective content of experience, the objective truth of experimental knowledge”. He believes that anyone who is ‘agnostic’ on the issue will inevitably fall into the idealist error of ‘solipsism’ - the belief that nothing outside your own mind can be certain to exist.
Lenin puts Mach and Bogdanov into this ‘agnostic’ category. He would certainly have also added Niels Bohr, with his philosophy that “it is wrong to think that the task of physics is to find out how nature is”, too.
He adds that the ‘agnostics’ accuse materialists of being ‘metaphysicians’ for insisting on the existence of an objective reality. This charge of having a non-scientific ‘metaphysical’ outlook is one that Rovelli also levels at Lenin – and it is an accusation that Einstein faced too.
“[The agnostics] call us, the materialists, ‘metaphysicians’ because we recognise objective reality which is given us in experience, because we recognise an objective source of our sensations independent of man. ... The agnostic says: I do not know if there is an objective reality which is reflected, imaged by our sensations; I declare there is no way of knowing this. Hence the denial of objective truth by the agnostic, and the tolerance - the philistine, cowardly tolerance - of the dogmas regarding sprites, hobgoblins, Catholic saints, and the like. ...
Matter is a philosophical category denoting the objective reality which is given to man by his sensations, and which is copied, photographed and reflected by our sensations, while existing independently of them. Therefore, to say that such a concept can become ‘antiquated’ is childish talk, a senseless repetition of the arguments of fashionable reactionary philosophy. Could the struggle between materialism and idealism, the struggle between the tendencies or lines of Plato and Democritus in philosophy, the struggle between religion and science, the denial of objective truth and its assertion, the struggle between the adherents of super-sensible knowledge and its adversaries have become antiquated during the two thousand years of the development of philosophy?”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
Mach – trying to find a middle ground
Rovelli’s claim that Lenin accuses Mach – and, in turn, Bogdanov – of being ‘idealists' isn’t quite correct. His actual accusation is they try and have it both ways, claiming that their approach finds a better ‘middle ground’ between “one-sided” idealism and materialism when, in fact, it just ends up creating confusion, camouflaged by clever-sounding ‘new’ terminology.
“It would, indeed, be childish to think that one can dispose of the fundamental philosophical trends by inventing a new word. Either the ‘element’ is a sensation, as all empirio-criticists, Mach etc., maintain - in which case your philosophy, gentlemen, is idealism vainly seeking to hide the nakedness of its solipsism under the cloak of a more ‘objective’ terminology; or the ‘element’ is not a sensation - in which case absolutely no thought whatever is attached to the ‘new’ term; it is merely an empty bauble. ...
[The Machians] combine fundamental idealist premises with individual materialist deductions for the very reason that their theory is an example of that ‘pauper’s broth of eclecticism’ of which Engels speaks with just contempt [in Engels’ foreword to ‘Ludwig Feuerbach and the End of Classical German Philosophy’].
Lenin, ‘Materialism and Empirio-Criticism’, Chapter One: ‘2. The Discovery of the World-Elements’
***
“Both the solipsist, that is, the subjective idealist, and the materialist may regard sensations as the source of our knowledge. ... The first premise of the theory of knowledge undoubtedly is that the sole source of our knowledge is sensation. Having recognised the first premise, Mach confuses the second important premise, i.e., regarding the objective reality that is given to man in his sensations, or that forms the source of man’s sensations. Starting from sensations, one may follow the line of subjectivism, which leads to solipsism (‘bodies are complexes or combinations of sensations’), or the line of objectivism, which leads to materialism (sensations are images of objects, of the external world).”
“For the first point of view, i.e., agnosticism, or, pushed a little further, subjective idealism, there can be no objective truth. For the second point of view, i.e., materialism, the recognition of objective truth is essential. This old philosophical question of the two trends, or rather, of the two possible deductions from the premises of empiricism and sensationalism, is not solved by Mach, it is not eliminated or overcome by him, but is muddled by verbal trickery with the word ‘element,’ and the like.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
To illustrate his point, Lenin discusses a concept that will be familiar to anyone who has studied even just a little school physics: what produces the ‘colour’ of an object? Lenin summarises (using the scientific terminology current at that time) how light rays of different wavelengths are detected by the retina, producing our sensation of colour.
The explanation would seem to be straightforward enough scientifically - but Lenin warns that Mach's ‘Empirio-Criticist’ philosophy, with its convoluted terminology about “elements”, including reference to colour being both a “physical object” and a “psychological object”, confuses matters, fudging the question as to whether it accepts the existence of an external objective reality or not.
“All natural science can only picture and represent complexes of those elements which we ordinarily call sensations. It is a matter of the connection of these elements. ... The connection of A (heat) with B (flame) is a problem of physics, that of A and N (nerves) a problem of physiology. Neither exists separately; both exist in conjunction. Only temporarily can we neglect either. Even processes that are apparently purely mechanical, are thus always physiological.”
Ernst Mach, ‘Mechanics’, 1883.
“A colour is a physical object as soon as we consider its dependence, for instance, upon its luminous source, upon other colours, upon temperatures, upon spaces, and so forth. When we consider, however, its dependence upon the retina, it is a psychological object, a sensation.”
Ernst Mach, ‘Analysis of Sensations’, 1890.
Mach, quoted by Lenin in ‘Materialism and Empirio-Criticism’, Chapter One: ‘2. The Discovery of the World-Elements’
***
“Light rays, falling upon the retina, produce the sensation of colour. This means that outside us, independently of us and of our minds, there exists a movement of matter, let us say of ether waves of a definite length and of a definite velocity, which, acting upon the retina, produce in man the sensation of a particular colour. This is precisely how natural science regards it. It explains the sensations of various colours by the various lengths of light-waves existing outside the human retina, outside man and independently of him.
This is materialism: matter acting upon our sense-organs produces sensation. Sensation depends on the brain, nerves, retina, etc., i.e., on matter organised in a definite way. The existence of matter does not depend on sensation. Matter is primary. Sensation, thought, consciousness are the supreme product of matter organised in a particular way. Such are the views of materialism in general, and of Marx and Engels in particular”.
Lenin’s response to Mach in the same chapter of ‘Materialism and Empirio-Criticism’
Lenin also argues that Mach’s confused philosophy is the source of Bogdanov’s philosophical – and perhaps political – confusion as well. He compares their misguided attempt to find a philosophical middle ground to the misguided attempt to do the same in politics.
“ ‘Of all parties’ our [German Marxist] Joseph Dietzgen justly said, ‘the middle party is the most repulsive. . . . Just as parties in politics are more and more becoming divided into two camps . . . so science too is being divided into two general classes: metaphysicians [idealists] on the one hand, and physicists, or materialists, on the other. The intermediate elements and conciliatory quacks, with their various appellations - spiritualists, sensationalists, realists, etc., etc. - fall into the current on their way. We aim at definiteness and clarity. ... If we compare the two parties respectively to solid and liquid, between them there is a mush.’
True! The ‘realists,’ etc., including the ‘positivists,’ the Machians, etc., are all a wretched mush; they are a contemptible middle party in philosophy, who confuse the materialist and idealist trends on every question. The attempt to escape these two basic trends in philosophy is nothing but ‘conciliatory quackery’.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Six: ‘4. Parties in Philosophy and Philosophical Blockheads’
Lenin emphasises that his approach is exactly that of Marx and Engels as well. But Lenin points out that this isn’t just the philosophy of Marxism, such a materialist outlook is also how science - or, at least, most scientists - view the world as well.
Lenin quotes the views of the Austrian physicist, Ludwig Boltzmann [whose name is still remembered in the ‘Boltzmann constant’ of modern physics], similarly opposing those, like Mach (and perhaps now Rovelli?!), who argue that “only sense-impressions are given us, and, therefore, it is said, we have no right to go a step beyond ”.
“Anybody who reads [Engels’ books] Anti-Dühring and Ludwig Feuerbach with the slightest care will find scores of instances when Engels speaks of things and their reflections in the human brain, in our consciousness, thought, etc. Engels does not say that sensations or ideas are ‘symbols’ of things, for consistent materialism must here use ‘image,’ picture, or reflection instead of ‘symbol,’ ... But the question here is not of this or that formulation of materialism, but of the opposition of materialism to idealism, of the difference between the two fundamental lines in philosophy. Are we to proceed from things to sensation and thought? Or are we to proceed from thought and sensation to things?
The first line, i.e., the materialist line, is adopted by Engels. The second line, i.e., the idealist line, is adopted by Mach. No evasions ... can remove the clear and indisputable fact that Ernst Mach’s doctrine that things are complexes of sensations is subjective idealism. ... If bodies are ‘complexes of sensations,’ as Mach says ... it inevitably follows that the whole world is but my idea. Starting from such a premise it is impossible to arrive at the existence of other people besides oneself: it is the purest solipsism.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter One: ‘1. Sensations and Complexes of Sensations’
***
“Writing against people who ‘have been carried away by the new epistemological dogmas,’ Boltzmann says: ‘Mistrust of conceptions which we can derive only from immediate sense-impressions has led to an extreme which is the direct opposite of former naïve belief. Only sense-impressions are given us, and, therefore, it is said, we have no right to go a step beyond. But to be consistent, one must further ask: are our sense-impressions of yesterday also given? What is immediately given is only the one sense-impression, or only the one thought, namely, the one we are thinking at the present moment. Hence, to be consistent, one would have to deny not only the existence of other people outside one’s self, but also all conceptions we ever had in the past.’ ... This physicist rightly ridicules the supposedly ‘new’ ‘phenomenalist’ view of Mach and Co. as the old absurdity of philosophical subjective idealism”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter One: ‘6. The Solipsism of Mach and Avenarius’
Rovelli and Mach
Before continuing with an analysis of Lenin’s writings, it might be useful to review in a bit more detail what Rovelli has to say about Mach’s philosophy. In ‘Helgoland’, Rovelli summarises his understanding of Mach’s thinking and what he sees as “the appeal of this philosophical position.”
In Rovelli’s view, “Mach does not think, of course, that there is nothing outside our mind. On the contrary, he is interested precisely in what is outside our minds (whatever the ‘mind’ is): nature, in all its complexity, of which we are a part. Nature presents itself as a set of phenomena, and Mach recommends the study of those phenomena in order to build syntheses and conceptual structures that make sense of them, rather than to postulate a priori underlying realities”.
However, I think Lenin would see Rovelli’s claim as an example of Machian “mush”, and that it’s the kind of thinking that troubled Boltzmann too. Reality exists but we shouldn’t “go a step beyond” and postulate about what that underlying reality consists of?
Rovelli goes into more detail into what he thinks constitutes Mach’s philosophy, writing that “For Mach, there is no distinction between the physical and the mental world ... Knowledge is divested of any ahistorical element, of every aspiration towards the absolute, or pretence of certainty ... This perspective, historical and concrete, resonates with the ideas of Marx and Engels”.
As explained below, in ‘Materialism and Empirio-Criticism’ Lenin refutes a similar claim to Marxist authenticity for such ideas, in reply to Bogdanov. Rovelli writes that Mach makes “no distinction between the physical and the mental world”. But Marxism does, and science need to do so as well.
“Mach does not see knowledge as a question of deducing or intuiting a hypothetical reality beyond sensations, but as the search for an efficient organisation of our way of thinking these sensations. The world that interests us, for Mach, is constituted by sensations. Any firm assumption about what lies 'behind' those sensations is suspect as being a form of 'metaphysics'.
The notion of 'sensation' is ambiguous in Mach. This is both his weakness and his strength: Mach takes the concept of sensation from physiology but makes it serve as a universal notion independent from the psychological sphere. He uses the term 'elements' (in a sense similar to dhamma in Buddhist philosophy). 'Elements' are not just the sensations that a human being or an animal experiences. They are any phenomena that manifest themselves in the universe. The 'elements' are not independent: they are tied by relations, what Mach calls 'functions', and these are what science studies. Though imprecise, Mach's philosophy is a real natural philosophy that replaces the mechanism of matter that moves in space with a general set of elements and functions.
The appeal of this philosophical position is that it eliminates every firm hypothesis concerning a reality that exists behind appearances, but also every hypothesis on the reality of the subject who experiences. For Mach, there is no distinction between the physical and the mental world: 'sensation' is equally physical and mental. It is real. ...
The idea of a material reality behind phenomena disappears; the idea of a spirit that 'knows' disappears. Knowledge is possessed, for Mach, not by the abstract 'subject' of idealism: it is instead the concrete human activity, in the concrete course of history, that learns to better and better organize the facts of the world with which it interacts.
This perspective, historical and concrete, resonates with the ideas of Marx and Engels, for whom knowledge is part of a concrete human history. Knowledge is divested of any ahistorical element, of every aspiration towards the absolute, or pretence of certainty; it is located instead in the actual biological, historical and cultural evolution of mankind on our planet”.
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
Rovelli certainly believes that a Machian approach benefits scientific thinking. In the first chapter of ‘Helgoland’, Rovelli stresses how Heisenberg had been influenced by “the discussions on the relation between reality and experience that ran through Austrian and German philosophy at the beginning of the century. Ernst Mach, who had exerted a decisive influence on Einstein, insisted that knowledge had to be based solely on observations, freed of any implicit ‘metaphysical’ assumption.”
It’s certainly seems true that Heisenberg was inspired to ‘think outside the box’ by the Machian philosophy that science should only consider known ‘observables’ and not any other prior assumptions about the nature of reality. However, as the section on Einstein above indicates, Rovelli would be wrong to imply that Einstein shared the same philosophical outlook.
“Mach argues that the progress of science shows that this notion of 'matter' is an unjustified 'metaphysical' assumption: a model that was useful for a time, but from which we need to learn how to move on, so that it does not become a metaphysical prejudice. Science must be freed from all metaphysical assumptions: knowledge should be based, that is, only upon what is 'observable'.”
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
“Let's change ... our way of thinking about the electron. Let's give up describing its movement. Let's describe only what we can observe: the light it emits. Let's base everything on quantities that are observable. This is the idea”. ...
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Absurd Idea of the Young Heisenberg: Observables’
“To Heisenberg's obscure idea that the theory only describes observations, and not what happens between one observation and another, we must add the idea that the theory predicts only the probability of observing one thing or another”.
Carlo Rovelli, ‘Helgoland’, Chapter I: ‘The Misleading Psi of Erwin Schrödinger: Probability’
Einstein certainly acknowledged that he had taken inspiration from some of Mach’s scientific writings that stressed the importance of considering motion relative to other bodies. However, far from wishing to free himself from the supposedly “metaphysical assumption” of objective reality, Einstein was critical of Heisenberg and Bohr for restricting themselves only to ‘observables’.
Einstein did not adopt a Machian outlook philosophically. Instead, as made clear in the 1949 article quoted above, Einstein believed that “the programmatic aim of all physics [was] the complete description of any (individual) real situation (as it supposedly exists irrespective of any act of observation)”.
Perhaps correcting any false impression that Rovelli might have created by writing that Mach “had exerted a decisive influence on Einstein”, in a later chapter, referencing the Einstein Bohr debates, Rovelli writes that “Einstein was resistant to the idea of relinquishing a more realistic image of phenomena. Bohr defended the conceptual novelty of the theory.” In the accompanying footnote Rovelli also acknowledges that, rather than taking Einstein’s perspective, “I follow more in the footsteps of Bohr and Heisenberg”. In case that was in any doubt!
Unfortunately, Rovelli is inconsistent in his writing on Mach. Elsewhere in ‘Helgoland’, Rovelli reverts to describing Mach as being “the source of philosophical inspiration for both Einstein and Heisenberg”.
Rovelli is also inconsistent in his support for Mach’s philosophy. In a later chapter of ‘Helgoland’, apparently in response to reading the American writer Erik C. Banks, he writes that “the attempt by Mach to take 'sensations' or 'elements' as foundational has inspired scientists and philosophers, but in the end does not seem any more convincing than others. Mach rails against metaphysics, but he effectively produces his own metaphysics - lighter and more flexible, but a metaphysics nonetheless of elements and functions. A phenomenal realism, or a 'realist empiricism'.”
So Rovelli seems to be unclear about what he thinks himself about Mach’s philosophy, one that he himself describes as being “imprecise” and “ambiguous”. Nevertheless, given his largely positive account of Machian thought, it’s not surprising that Rovelli is so vociferously opposed to his critic, Lenin.
Lenin, as we have seen, was forthright in his opposition to Mach’s ‘Empirio-Criticism’, and insisted that Marxists “aim at definiteness and clarity”. And, as we shall now see, Lenin was similarly firm in his opposition to the other ‘Machian’ that Rovelli writes approvingly of, Bogdanov, who had claimed to have developed his own philosophical framework, ‘Empirio-Monism”.
Bogdanov's ‘Empirio-Monism’
As Lenin explains, Bogdanov, writing in 1906, claimed to have a different approach to Mach. But Lenin retorts that his ‘Empirio-Monism’ is founded on exactly the same lack of “distinction between the physical and the mental world”. Just as with Mach, Lenin believed that “what appeared to Bogdanov to be truth is, as a matter of fact, confusion, a wavering between materialism and idealism”.
“Bogdanov, arguing against Plekhanov in 1906 wrote: ‘I cannot own myself a Machian in philosophy. In the general philosophical conception there is only one thing I borrowed from Mach—the idea of the neutrality of the elements of experience in relation to the ‘physical’ and ‘psychical’ and the dependence of these characteristics solely on the connection of experience. [Empirio-Monism]’ ... This is as though a religious man were to say - I cannot own myself a believer in religion, for there is ‘only one thing’ I have borrowed from the believers - the belief in God. This ‘only one thing’ which Bogdanov borrowed from Mach is the basic error of Machism, the basic falsity of its entire philosophy.
Those deviations of Bogdanov’s from empirio-criticism to which he himself attaches great significance are in fact of entirely secondary importance and amount to nothing more than inconsiderable private and individual differences between the various empirio-criticists ... How Bogdanov developed, improved or worsened Machism is not important. What is important is that he has abandoned the materialist standpoint and has thereby inevitably condemned himself to confusion and idealist aberrations. ...
What appeared to Bogdanov to be truth is, as a matter of fact, confusion, a wavering between materialism and idealism”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter One: ‘2. The Discovery of the World-Elements’
Bogdanov sought to add a new angle to Mach’s thought by introducing the notion that objectivity in human models of physical reality comes about when individual ideas become ‘collectively’ accepted as “socially organised experience”.
Rovelli summarises this with the following quote from Bogdanov’s ‘Empirio-Monism’: “The difference between the psychological and physical orders boils down to the difference between experience organized individually and experience organized socially.” [‘Helgoland’, Chapter Vll, ‘But is It Really Possible?’]. But Lenin counters that this is still fundamentally an idealist outlook, because “the physical world exists independently of humanity and of human experience, [it] existed at a time when no ‘sociality’ and no ‘organisation’ of human experience was possible”.
“ ‘The basis of objectivity,’ we read in Book I of Empirio-Monism, ‘must lie in the sphere of collective experience. We term those data of experience objective which have the same vital meaning for us and for other people, those data upon which not only we construct our activities without contradiction, but upon which, we are convinced, other people must also base themselves in order to avoid contradiction. The objective character of the physical world consists in the fact that it exists not for me personally, but for everybody ...
The objectivity of the physical bodies we encounter in our experience is in the last analysis established by the mutual verification and coordination of the utterances of various people. In general, the physical world is socially-co-ordinated, socially-harmonised, in a word, socially-organised experience’.
This is a fundamentally untrue, idealist definition, ... the physical world exists independently of humanity and of human experience, [it] existed at a time when no ‘sociality’ and no ‘organisation’ of human experience was possible”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
Lenin also warns that defining ‘objectivity’ as being based on “socially organised experience” allows religious doctrines to be seen as being equally ‘objective’. After all, “Catholicism has been ‘socially organised, harmonised and co-ordinated’ by centuries of development”.
“If truth is only an organising form of human experience, then the teachings, say, of Catholicism are also true. ... Catholicism has been ‘socially organised, harmonised and co-ordinated’ by centuries of development ... If this undoubtedly universally significant and undoubtedly highly-organised religious social experience does ‘not harmonise’ with the ‘experience’ of science, it is because there is a radical and fundamental difference between the two, which Bogdanov obliterated when he rejected objective truth. ...
Contemporary fideism [religious faith] does not at all reject science; all it rejects is the ‘exaggerated claims’ of science, to wit, its claim to objective truth. If objective truth exists (as the materialists think), if natural science, reflecting the outer world in human ‘experience,’ is alone capable of giving us objective truth, then all fideism is absolutely refuted.
But if there is no objective truth, if truth (including scientific truth) is only an organising form of human experience, then this in itself is an admission of the fundamental premise of clericalism, the door is thrown open for it, and a place is cleared for the ‘organising forms’ of religious experience”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
Lenin adds that Bogdanov believes that his theory of ‘Empirio-Monism’ updates and “develops” Marxism as follows [the emphasis is taken from Bogdanov’s original text]: “In their struggle for existence men can unite only with the help of consciousness: without consciousness there can be no intercourse. Hence, social life in all its manifestations is a consciously psychical life. ... Society is inseparable from consciousness. Social being and social consciousness are, in the exact meaning of these terms, identical”. [Chapter Six: ‘2. How Bogdanov Corrects and “Develops” Marx’]
But Lenin counters that this is not a Marxist position, making a point that is still very relevant for socialists taking into account today of the gap that exists between objective conditions and working-class consciousness: “Social consciousness reflects social being - that is Marx’s teaching. A reflection may be an approximately true copy of the reflected, but to speak of identity is absurd ... people in their intercourse are not conscious of what kind of social relations are being formed.”
“‘Social being’ and ‘social consciousness’ are not identical, just as being in general and consciousness in general are not identical. From the fact that in their intercourse men act as conscious beings, it does not follow that social consciousness is identical with social being. In all social formations of any complexity - and in the capitalist social formation in particular - people in their intercourse are not conscious of what kind of social relations are being formed, in accordance with what laws they develop, etc. For instance, a peasant when he sells his grain enters into “intercourse” with the world producers of grain in the world market, but he is not conscious of it; nor is he conscious of the kind of social relations that are formed on the basis of exchange. ...
Social consciousness reflects social being - that is Marx’s teaching. A reflection may be an approximately true copy of the reflected, but to speak of identity is absurd. ... Bogdanov’s attempt to correct and develop Marx ... is an obvious distortion of this materialist basis in the spirit of idealism ... of the identity of consciousness and being. ...
Bogdanov personally is a sworn enemy of reaction in general and of bourgeois reaction in particular. [However,] Bogdanov’s ... theory of the ‘identity of social being and social consciousness’ serve this reaction. It is sad, but true”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Six: ‘2. How Bogdanov Corrects and “Develops” Marx’
Lenin, in the same chapter quoted above, then draws together the political and philosophical points: “Materialism in general recognises objectively real being (matter) as independent of consciousness, sensation, experience, etc., of humanity. Historical materialism recognises social being as independent of the social consciousness of humanity. In both cases consciousness is only the reflection of being, at best an approximately true ... reflection of it. From this Marxist philosophy, which is cast from a single piece of steel, you cannot eliminate one basic premise, one essential part, without departing from objective truth, without falling a prey to a bourgeois-reactionary falsehood”.
Lenin warns that Bogdanov’s philosophy is “disguised in Marxist terminology and decked out in Marxist words. ‘Socially organised experience,’ ‘collective labour process,’ and so forth are Marxist words, but they are only words, concealing an idealist philosophy that declares things to be complexes of ‘elements,’ of sensations, the external world to be ‘experience,’ or an ‘empirio-symbol’ of mankind, physical nature to be a ‘product’ of the ‘psychical,’ and so on and so forth”. [Chapter Six: ‘2. How Bogdanov Corrects and “Develops” Marx’]
Is Bogdanov’s ‘Empirio-Monism’ really a firm philosophical basis for modern physics? Personally, I think not. Is it accurate to say it ‘updates’ Marxism? Again, I think not - and nor does Lenin!
Does Objective Truth Exist?
As I set out above, Rovelli is opposed to what he sees as Lenin’s ‘dogmatism’, complaining that “Lenin presents the historical materialism of Marx and Engels as if it were timelessly valid” ... in a way that “fails to accord with the dynamic of scientific thought”. But Lenin has already responded to these kind of accusations in advance – in the pages of ‘Materialism and Empirio-Criticism’.
A similar criticism was raised by Bogdanov in his ‘Empirio-Monism’ when he wrote that “as I understand it, Marxism contains a denial of the unconditional objectivity of any truth whatsoever, the denial of all eternal truths” and declares that he recognises “objective truth only within the limits of a given epoch. ... The criterion of objective truth ... does not exist - truth is an ideological form, an organising form of human experience”. But Lenin points out the “absurdity” of such a claim, for if ‘truth’ is determined by human thought, then “there can be no truth independent of humanity”.
“If truth is only an ideological form, then there can be no truth independent of the subject, of humanity, for neither Bogdanov nor we know any other ideology but human ideology. And ... if truth is a form of human experience, then there can be no truth independent of humanity; there can be no objective truth. ... Bogdanov’s denial of objective truth is agnosticism and subjectivism.
... Natural science leaves no room for doubt that its assertion that the earth existed prior to man is a truth. The assertion ... is an objective truth. This proposition of natural science is incompatible with the philosophy of the Machians and with their doctrine of truth: if truth is an organising form of human experience, then the assertion that the earth exists outside human experience cannot be true”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
To present things fairly, it must be added that Rovelli, in line with most quantum theorists, doesn’t believe in any requirement for observations to be ‘human’ interactions. As he states in ‘Helgoland‘, quantum theory “describes how every physical object manifests itself to any other physical object”. However, his professed support for Bogdanov betrays another inconsistency in Rovelli’s thinking.
Both Bogdanov and Rovelli seem muddled on the actual views of Marxism, in particular, on how it explains the difference between ‘absolute’ and ‘relative’ truth, and on how our understanding of the nature of objective reality is tested and modified over time through ‘practice’.
Lenin quotes Engels explaining how, unlike the ‘Kantian agnostics’, Marxists believe that the nature of underlying reality, the ‘things-in-themselves’, can be revealed, as our knowledge becomes, in Lenin’s words below, “more complete”. Quantum theory may be revealing the nature of that reality to be more complex than we previously realised, but, nevertheless, it forms an objective reality.
“If we are able to prove the correctness of our conception of a natural process by making it ourselves ... then there is an end to the Kantian incomprehensible ‘thing-in-itself.’ ... The chemical substances produced in the bodies of plants and animals remained just such ‘things-in-themselves’ until organic chemistry began to produce them one after another, where upon the ‘thing-in-itself’ became a ‘thing for us,’ as, for instance, alizarin, the colouring matter of the madder, which we no longer trouble to grow in the madder roots in the field, but produce much more cheaply and simply from coal tar”.
Lenin, quoting Engels from ‘Ludwig Feuerbach and the End of Classical German Philosophy’
Lenin expands further on these points in a section which I have quoted at some length below:
“What is the kernel of Engels’ objections? Yesterday we did not know that coal tar contained alizarin. Today we learned that it does. The question is, did coal tar contain alizarin yesterday? Of course it did. To doubt it would be to make a mockery of modern science. And if that is so, three important epistemological conclusions follow:
1) Things exist independently of our consciousness, independently of our perceptions, outside of us, for it is beyond doubt that alizarin existed in coal tar yesterday and it is equally beyond doubt that yesterday we knew nothing of the existence of this alizarin and received no sensations from it.
2) There is definitely no difference in principle between the phenomenon and the thing-in-itself, and there can be no such difference. The only difference is between what is known and what is not yet known. And philosophical inventions of specific boundaries between the one and the other, inventions to the effect that the thing-in-itself is ‘beyond’ phenomena (Kant), or that we can and must fence ourselves off by some philosophical partition from the problem of a world which in one part or another is still unknown but which exists outside us (Hume) - all this is the sheerest nonsense.
3) In the theory of knowledge, as in every other branch of science, we must think dialectically, that is, we must not regard our knowledge as ready-made and unalterable, but must determine how knowledge emerges from ignorance, how incomplete, inexact knowledge becomes more complete and more exact.
Once we accept the point of view that human knowledge develops from ignorance, we shall find millions of examples of it just as simple as the discovery of alizarin in coal tar, millions of observations not only in the history of science and technology but in the everyday life of each and every one of us that illustrate the transformation of “things-in-themselves” into “things-for-us,” ...
The sole and unavoidable deduction to be made from this - a deduction which all of us make in everyday practice and which materialism deliberately places at the foundation of its epistemology - is that outside us, and independently of us, there exist objects, things, bodies and that our perceptions are images of the external world. Mach’s converse theory (that bodies are complexes of sensations) is nothing but pitiful idealist nonsense”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘1. The “Thing-in-Itself” ’
But Lenin knows that idealist critics of Marxist materialism will demand to know “what proof have you that the human mind gives you an objective truth?” He gives Marx and Engels’ replies.
“Marx naturally encounters the objections of the critics. He has admitted the existence of things-in-themselves, of which our theory is the human translation; he cannot evade the usual objection: what assurance have you of the accuracy of the translation? What proof have you that the human mind gives you an objective truth? To this objection Marx replies in his second Thesis” [on Feuerbach] : ‘The question whether objective truth can be attributed to human thinking is not a question of theory, but is a practical question. In practice man must prove the truth, i.e., the reality and power, the ‘this-sidedness’ of his thinking. The dispute over the reality or non-reality of thinking which is isolated from practice is a purely scholastic question.’
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘1. The “Thing-in-Itself” ’
***
“The proof of the pudding is in the eating. From the moment we turn to our own use these objects, according to the qualities we perceive in them, we put to an infallible test the correctness or otherwise of our sense-perceptions. If these perceptions have been wrong, then our estimate of the use to which an object can be turned must also be wrong, and our attempt must fail. But if we succeed in accomplishing our aim, if we find that the object does agree with our idea of it, and does answer the purpose we intended it for, then that is positive proof that our perceptions of it and of its qualities, so far, agree with reality outside ourselves. ...
Lenin, quoting Engels’ Introduction to the English edition of ‘Socialism: Utopian and Scientific’
However, Lenin adds an important caveat to the idea that perhaps ‘practice makes perfect’. He points out that it can never “confirm or refute any human idea completely”. In doing so, he answers Rovelli’s (and Bogdanov’s) accusation in advance that “Lenin speaks of absolute certainties”.
“Of course, we must not forget that the criterion of practice can never, in the nature of things, either confirm or refute any human idea completely. This criterion also is sufficiently “indefinite” not to allow human knowledge to become “absolute,” but at the same time it is sufficiently definite to wage a ruthless fight on all varieties of idealism and agnosticism”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘6. The Criterion of Practice’
Absolute and Relative Truth
Rovelli is perhaps making the same errors that led Lenin to charge Bogdanov of being in a “complete muddle” over these issues. Lenin put this down to Bogdanov’s “failure to understand the relation of absolute truth to relative truth ”.
Rovelli writes that Lenin is “forgetting one of the essential lessons of Marx and Engels: history is process, knowledge is process. Scientific knowledge grows, writes Bogdanov, and the notion of matter proper to the science of our time may turn out to be only an intermediate stage on the path of our knowledge. Reality may be much more complex than the naïve materialism of eighteenth-century physics”. [‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’]
But where is Rovelli’s evidence for this accusation? Since the time of Marx, Engels and Lenin, new experimental findings have of course meant that our models of the nature of reality have had to change. But none of these three would have had any difficulty at all in accepting that. Anyone arguing otherwise misunderstands Marxism.
What Lenin – and Marxism in general – does not accept is the idea, which Machians like Bogdanov proposed, that “the relativity of our knowledge excludes even the least admission of absolute truth”. As Lenin explains, “for Engels, absolute truth is compounded from relative truths. Bogdanov is a relativist; Engels is a dialectician”. [‘M & E-C’: Chapter Two: ‘5. Absolute and Relative Truth’]
“Human thought ... is capable of giving, and does give, absolute truth, which is compounded of a sum-total of relative truths. Each step in the development of science adds new grains to the sum of absolute truth, but the limits of the truth of each scientific proposition are relative, now expanding, now shrinking with the growth of knowledge ... ‘Absolute truth ... can be seen, heard, smelt, touched and, of course, also be known, but it is not entirely absorbed into knowledge’ ”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘5. Absolute and Relative Truth’
Lenin knows that this distinction between relative and absolute truth will be too ‘indefinite’ for some of his critics to accept. But Lenin replies as follows: “It is sufficiently ‘indefinite’ to prevent science from becoming a dogma”. This is part of a longer reply (copied below) to Bogdanov’s accusation that Lenin failed to recognise the ‘historically conditional nature’ of knowledge. In it, Lenin also responds to the accusation that Marxist political and ideological thought is ‘dogmatic’ too.
This passage also answers Rovelli’s false accusation that Marxist thought resists change in scientific thought. No, it welcomes every scientific advance as another step towards a full picture of the nature of objective reality in which we exist.
“For dialectical materialism there is no impassable boundary between relative and absolute truth. Bogdanov entirely failed to grasp this if he could write: ‘It [the world outlook of the old materialism] sets itself up as the absolute objective knowledge of the essence of things and is incompatible with the historically conditional nature of all ideologies’ (Empirio-monism). From the standpoint of modern materialism i.e., Marxism, the limits of approximation of our knowledge to objective, absolute truth are historically conditional, but the existence of such truth is unconditional, and the fact that we are approaching nearer to it is also unconditional. The contours of the picture are historically conditional, but the fact that this picture depicts an objectively existing model is unconditional”.
When and under what circumstances we reached, in our knowledge of the essential nature of things, the discovery of alizarin in coal tar or the discovery of electrons in the atom is historically conditional; but that every such discovery is an advance of ‘absolutely objective knowledge’ is unconditional. In a word, every ideology is historically conditional, but it is unconditionally true that to every scientific ideology (as distinct, for instance, from religious ideology) there corresponds an objective truth, absolute nature.
You will say that this distinction between. relative and absolute truth is indefinite. And I shall reply: it is sufficiently ‘indefinite’ to prevent science from becoming a dogma in the bad sense of the term, from becoming something dead, frozen, ossified; but at the same time it is sufficiently ‘definite’ to enable us to dissociate ourselves. in the most emphatic and irrevocable manner from fideism and agnosticism, from philosophical idealism and the sophistry of the followers of Hume and Kant. ...
The materialist dialectics of Marx and Engels certainly does contain relativism, but is not reducible to relativism, that is, it recognises the relativity of all our knowledge, not in the sense of denying objective truth, but in the sense that the limits of approximation of our knowledge to this truth are historically conditional.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘5. Absolute and Relative Truth’
***
”Bogdanov is prepared to recognise Marx’s theory of the circulation of money as an objective truth only for ‘our time’, and calls it ‘dogmatism’ to attribute to this theory a ‘super-historically objective’ truth. This is again a muddle. The correspondence of this theory to practice cannot be altered by any future circumstances ... But inasmuch as the criterion of practice, i.e., the course of development of all capitalist countries in the last few decades, proves only the objective truth of Marx’s whole social and economic theory in general, and not merely of one or other of its parts, formulations, etc., it is clear that to talk of the ‘dogmatism’ of the Marxists is to make an unpardonable concession to bourgeois economics. ...
The sole conclusion to be drawn from the opinion of the Marxists that Marx’s theory is an objective truth is that by following the path of Marxist theory we shall draw closer and closer to objective truth (without ever exhausting it); but by following any other path we shall arrive at nothing but confusion and lies.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘6. The Criterion of Practice’
‘Relativism’ and ‘Relativity’
In re-reading Lenin’s reasoning in the context of today’s scientific knowledge, it’s important to draw a distinction between the scientific theory of ‘relativity’ and the philosophical outlook of ‘relativism”. Lenin is not discussing the scientific understanding that phenomena can appear differently depending on your frame of reference, nor about relativistic effects such as the ‘bending’ of light by gravity (after all, Einstein hadn’t yet written his paper on General Relativity and it wasn’t experimentally confirmed by Eddington until 1919). Lenin is instead referring to “relativism”, the idea that there is no ‘absolute truth’ and that different models of the world can be equally valid.
The history of science shows that, particularly at a time when commonly held scientific models are being challenged, more than one scientific model may indeed seem to offer as much validity as another. For example, when Copernicus first put forward a ‘sun-centred’ model of the universe, experimental observations of planetary movement could probably be as equally well explained by previous ‘Ptolemaic earth-centred’ models. Copernicus, Kepler and their followers were probably as equally swayed by other influences such as ‘occult’ beliefs in the power of the Sun! However, additional observations and scientific theories showed that one model provided a better explanation of reality than the previously held model.
Indeed, the development of relativity theory confirms the dialectical approach to the development of knowledge outlined by Lenin above. It was becoming clear that classical Newtonian mechanics only gave an accurate picture of the world around us within certain limits. Beyond these limits, a new, more refined, model of reality was required. Einstein’s theories provided the basis of that new model. Newtonian physics could no longer be seen as giving equally valid explanations of reality.
But Mach had a different philosophy. Lenin compares Engels’ insistence on the ‘criterion of practice’ - “the result of our action proves the conformity of our perceptions with the objective nature of the things perceived” - with Mach’s relativism.
Lenin quotes [in ‘6. The Criterion of Practice’] from Mach’s ‘Analysis of Sensations’ as follows: “In the common way of thinking and speaking appearance, illusion, is usually contrasted with reality. A pencil held in front of us in the air is seen as straight; when we dip it slantwise into water we see it as crooked. In the latter case we say that the pencil appears crooked but in reality it is straight. But what entitles us to declare one fact to be the reality, and to degrade the other to an appearance?”.
This passage serves as a useful insight into Lenin’s criticism of Machian thought. The ‘crooked’ appearance of a pencil dipped into water is indeed surely just an optical illusion. It owes nothing to Einstein’s relativity, there are no frames of reference moving at velocities close to the speed of light. It owes nothing to quantum mechanics, a pencil is far too large an object for such effects to be appreciable. It would take little experimental investigation to show that the pencil was indeed straight and that the illusion is caused by the differing speeds of light in air and water.
However, Mach’s explanation of the ‘crooked pencil’ is as follows: “Our expectation is deceived when we fall into the natural error of expecting what we are accustomed to although the case is unusual. The facts are not to blame for that. In these cases, to speak of appearance may have a practical significance, but not a scientific significance. Similarly, the question which is often asked, whether the world is real or whether we merely dream it, is devoid of all scientific significance. Even the wildest dream is a fact as much as any other.” As Lenin comments, “also the wildest philosophy” (!).
Now Mach’s advice not to draw conclusions based “on what we are accustomed to” can be useful advice, and perhaps advice that may have helped Einstein to consider new models of reality. Lenin himself, in an extract jotted down in his personal “Philosophical Notebooks”, noted how a “flight of fantasy” was sometimes a part of scientific process.
“The approach of the (human) mind to a particular thing, the taking of a copy (= concept) of it is not a simple, immediate act, a dead mirroring, but one which is complex, split in two, zigzag like, which includes in it the possibility of the flight of fantasy from life; more than that: The possibility of the transformation (moreover, an unnoticeable transformation, of which man is unaware) of the abstract concept, idea, into a fantasy. ... For even in the simplest generalisation, in the most elementary general idea ... there is a certain bit of fantasy. (Vice versa, it would be stupid to deny the role of fantasy, even in the strictest science...)
Lenin, “Philosophical Notebooks”: ‘Conspectus of Aristotle’s Book Metaphysics’, 1915.
However, to conclude, as Mach does in ‘Analysis of Sensations’, that it is irrelevant for a scientist to ask “whether the world is real or whether we merely dream it” is a step too far, a step that takes science away from a materialist insistence on objective reality – and a step that Einstein, for one, was not prepared to take.
Lenin instead stresses the dialectical outlook of Marxism, an outlook that sees the world not, as its critics suggest, as one “devoid of sound and colour” but one that is “richer, livelier, more varied than it actually seems, for with each step in the development of science new aspects are discovered”.
“The Machists love to declaim that they are philosophers who completely trust the evidence of our sense-organs, who regard the world as actually being what it seems to us to be, full of sounds, colours, etc., whereas to the materialists, they say, the world is dead, devoid of sound and colour, and in its reality different from what it seems to be, and so forth ...
But, in fact, the Machians are subjectivists and agnostics, for they do not sufficiently trust the evidence of our sense-organs and are inconsistent in their sensationalism. They do not recognise objective reality, independent of man, as the source of our sensations. They do not regard sensations as a true copy of this objective reality, thereby directly conflicting with natural science and throwing the door open for fideism.
On the contrary, for the materialist the world is richer, livelier, more varied than it actually seems, for with each step in the development of science new aspects are discovered. For the materialist, sensations are images of the sole and ultimate objective reality, ultimate not in the sense that it has already been explored to the end, but in the sense that there is not and cannot be any other.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
In isolation, these philosophical debates can seem abstract. However, ‘Materialism and Empirio-Criticism’ also includes chapters where Lenin applies his philosophy to the scientific debates of that time. They show that Lenin was far from ‘dogmatic’ about scientific theory. On the contrary, he explains that Marxism fully expects scientific theory to change as new scientific evidence emerges.
Was Lenin ‘outdated’ and ‘dogmatic’ about scientific thought?
Rovelli accuses Lenin of supporting an outdated scientific model of the universe. But an objective reading of ‘Materialism and Empirio-Criticism’ shows that Lenin was taking on board the latest scientific thinking that he was able to gather from his research.
The same accusation might just as well be levelled against some of the best scientific minds of the period, like Maxwell or Lorentz, both of whom had made key contributions to the latest scientific thinking, but who operated within the confines of the now ‘outdated’ idea of the ‘ether’, as discussed above.
There was nothing ‘outdated’ or ‘dogmatic’ about Lenin’s references to ‘ether’ in 1908/9. At the time, only a small number of physicists had read and understood the significance of Einstein’s 1905 papers (and I don’t think there is any indication that Lenin was aware of Einstein’s work from his research). Lenin was simply reflecting the model that was generally accepted by most physicists at that point. However, Lenin was clearly aware that existing models were being challenged by new scientific evidence, as his chapter entitled ‘The Crisis in Modern Physics’, discussed below, makes very clear.
In setting out his general approach to scientific thought, Lenin refers to Engels’ writing on science which stressed that genuine Marxism, dialectical materialism, rejected a mechanical approach that imposed “fixed boundary lines and distinctions”. He adds that recent evidence, including in radioactivity and electromagnetism, had shown how things that had previously been thought to be entirely separate were, in fact, closely connected.
“ ‘In the most varied fields of natural science,’ writes [Hungarian Marxist] Diner-Dénes, ‘new knowledge has been acquired, all of which tends to that single point which Engels desired to make clear, namely, that in nature ‘there are no irreconcilable contradictions, no forcibly fixed boundary lines and distinctions,’ and that if contradictions and distinctions are met with in nature, it is because we alone have introduced their rigidity and absoluteness into nature’.
It was discovered, for instance, that light and electricity are only manifestations of one and the same force of nature. Each day it becomes more probable that chemical affinity may be reduced to electrical processes. The indestructible and non-disintegrable elements of chemistry, whose number continues to grow as though in derision of the unity of the world, prove to be destructible and disintegrable. The element radium has been converted into the element helium”.
‘Materialism and Empirio-Criticism’, Chapter Five: ‘The Recent Revolution in Natural Science’
Lenin recognised, as understood by a dialectical approach, that previously accepted models of science would show themselves to be correct only within certain limits. He draws attention to one of the most recently proposed examples of this, theories that suggested that the physics of objects travelling at very high velocities was going to have to go beyond earlier, Newtonian, limits.
“[Previously] mechanics was a copy of real motions of moderate velocity, while the new physics is a copy of real motions of enormous velocity. The recognition of theory as a copy, as an approximate copy of objective reality, is materialism”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’
Given the date of Materialism and Empirio-Criticism, this reference is unlikely to be based on an awareness of Einstein’s ‘Special Relativity’. However, Lenin instead refers specifically to the “modern physicists” Larmor and Lorentz. They had already both hypothesised, in the years prior to Einstein's fully developed theoretical explanation of the issues, that ‘time dilation’ and ‘length contraction’ were needed to explain how physics applies to objects travelling at speeds close to that of light.
One of Lenin's sources is a book by the French professor, Abel Rey [‘The Physical Theory of the Modern Physicists’, Paris, 1907]. Lenin describes Rey himself as being a “muddlehead and a semi-Machian”, but nevertheless feels he provides good source material because “Rey summarises carefully and in general conscientiously the extremely abundant literature on the subject, not only French, but English and German as well”. [M & E-C’, Chapter Five: ‘1. The Crisis in Modern Physics”]
Lenin quotes approvingly from Rey, showing his appreciation for the idea that, if Larmor and Lorentz were proved through experiment to be correct, “constancy of mass ... would be valid only for moderate velocities of bodies”. There is therefore every reason to believe that Lenin would have also approved of Einstein’s ‘Special Relativity’ as well.
“... If, for example, the recent hypotheses of Lorentz, Larmor and Langevin were, thanks to certain experimental confirmation, to obtain a sufficiently stable basis for the systematisation of physics, it would be certain that the laws of present-day mechanics are nothing but a corollary of the laws of electromagnetism: they would constitute a special case of the latter within well-defined limits. Constancy of mass and our principle of inertia would be valid only for moderate velocities of bodies, the term ‘moderate’ being taken in relation to our senses and to the phenomena which constitute our general experience. A general recasting of mechanics would result, and hence also, a general recasting of the systematisation of physics”.
Lenin, quoting Abel Rey, in ‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’
Far from being resistant to theoretical advances in physics, Lenin is clear that Marxism is a philosophy that insists that scientific theory has to accord with practice – and consequently has to change when new scientific discoveries require it to do so. Far from insisting dogmatically that previous propositions must not be revised, Lenin asserts that “on the contrary, [this] is demanded by Marxism”.
“Engels says explicitly [in Ludwig Feuerbach] that ‘with each epoch making discovery even in the sphere of natural science [‘not to speak of the history of mankind’], materialism has to change its form’. Hence, a revision of the ‘form’ of Engels’ materialism, a revision of his natural-philosophical propositions is not only not ‘revisionism,’ in the accepted meaning of the term, but, on the contrary, is demanded by Marxism”.
‘Materialism and Empirio-Criticism’, Chapter Five: ‘The Recent Revolution in Natural Science’
The ‘Crisis in Modern Physics’
Materialism and Empirio-Criticism was written too soon historically to give an opinion about either General Relativity or Quantum Mechanics. But Lenin’s writings about other, now largely forgotten, debates within the scientific community help to illustrate the method that Lenin would have applied. These are concentrated in the two chapters entitled “The Crisis in Modern Physics” and “Matter has Disappeared”. They demonstrate an outlook that is a long way from that of the narrow “naïve materialism” that Rovelli implies it would be.
First of all, Lenin appreciates that he is not a professional physicist with the expertise to give a fully informed opinion on the “specific physical theories” under discussion in the latest scientific debates. However, he does feel qualified to give a philosophical opinion on “the epistemological conclusions that follow from certain definite propositions and generally known discoveries”.
“It goes without saying that in examining the connection between one of the schools of modern physicists and the rebirth of philosophical idealism, it is far from being our intention to deal with specific physical theories. What interests us exclusively is the epistemological conclusions that follow from certain definite propositions and generally known discoveries”.
Materialism & Empirio-Criticism’, Chapter Five: ‘The Recent Revolution in Natural Science’
The title of the first of these two chapters, “The Crisis in Modern Physics”, paraphrases the words of the French physicist Henri Poincaré, who had written that new unexplained experimental evidence and conflicting theories were “signs of a serious crisis” in physics. These conflicts were nothing to do with General Relativity or Quantum Mechanics. This was an earlier ‘crisis’ arising from the ‘null result’ of the ‘Michelson-Morley experiment’ and other new experimental findings.
One of the new findings had been the ‘discovery’ of the electron. In 1897, the British physicist J.J. Thomson had carried out experiments on ‘cathode rays’ and concluded that they must be made up of the negatively charged particles that we now call electrons. His experiments allowed him to make a good estimate of the mass of an electron, Thomson reckoning it to be about a thousandth of the mass of a hydrogen ion (what we now call a proton – with today’s measurement giving the rest mass of an electron as about 1/1836 the mass of a proton).
Thomson further proposed that atoms must be made up of a ball of positive charge into which these negative electrons were embedded (the so-called 'plum pudding model').
In ‘Materialism and Empirio-Criticism’, Lenin describes what was then an alternative ‘solar system’ model where “the atom can be explained as resembling an infinitely small solar system, within which negative electrons move around a positive electron”. [Chapter Five: ‘2. “Matter has Disappeared” ’] This was the precursor of the now better known ‘nuclear’ model proposed by Rutherford in 1911, based on his analysis of the results of Geiger and Marsden's 'alpha-particle scattering experiments’.
Further experiments, in 1901-3, by the German physicist Walter Kaufmann, suggested (correctly) that an electron’s mass actually depended on its velocity. However, until Einstein was able to explain this finding as being due to ‘relativistic mass’ (summed up in his well-known E=mc^2 equation), some scientists concluded (wrongly, as it turned out) that mass must therefore depend solely on electromagnetic forces. This was being interpreted by some scientists as proof that mass – and therefore matter – didn’t actually exist at all. Some philosophers went further to say that, therefore, there could be no basis for materialism.
Lenin’s response to these claims is significant. He doesn’t argue against the (apparent) scientific evidence of ‘zero mass’ but only that it provided no basis on which to draw a false ‘idealist’ conclusion that matter therefore does not exist. He writes that “the ‘disappearance of matter’ ... has no relation to the epistemological distinction between materialism and idealism. When the physicists say that ‘matter is disappearing,’ they mean that hitherto science reduced its investigations of the physical world to three ultimate concepts: matter, electricity and ether; whereas now only the two latter remain.” [‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’]
In summary, as can be read in more detail in the longer extract, Lenin stresses that new theories questioning the existence of ‘matter’ – or at least matter in the form it had previously been described – simply demonstrated “that our knowledge is penetrating deeper”, taking a further step, ‘from relative truth to absolute truth’, towards understanding the actual nature of objective reality.
“The principle of the conservation of mass has been undermined by the electron theory of matter. According to this theory atoms are composed of very minute particles called electrons, which are charged with positive or negative electricity and ‘are immersed in a medium which we call the ether.’ The experiments of physicists provide data for calculating the velocity of the electrons and their mass ... The velocity proves to be comparable with the velocity of light (300,000 kilometres per second), attaining, for instance, one-third of the latter. Under such circumstances the twofold mass of the electron has to be taken into account, corresponding to the necessity of overcoming the inertia, firstly, of the electron itself and, secondly, of the ether. The former mass will be the real or mechanical mass of the electron, the latter the ‘electrodynamic mass which represents the inertia of the ether.’
And it turns out that the former mass is equal to zero. The entire mass of the electrons, or, at least, of the negative electrons, proves to be totally and exclusively electrodynamic in its origin. Mass disappears. The foundations of mechanics are undermined.”
Lenin, Materialism and Empirio-Criticism’, Chapter Five: ‘1. The Crisis in Modern Physics
***
”It has become possible to reduce matter to electricity ... It is consequently possible to reduce the physical world from scores of elements to two or three elements (inasmuch as positive and negative electrons constitute “two essentially distinct kinds of matter,”) ... such is the real meaning of the statement regarding the disappearance of matter, its replacement by electricity, etc., which is leading so many people astray.
‘Matter is disappearing’ means that the limit within which we have hitherto known matter disappears and that our knowledge is penetrating deeper; properties of matter are likewise disappearing which formerly seemed absolute, immutable, and primary (impenetrability, inertia, mass etc.) and which are now revealed to be relative and characteristic only of certain states of matter. For the sole ‘property’ of matter with whose recognition philosophical materialism is bound up is the property of being an objective reality, of existing outside our mind. ...
... the recognition of immutable elements, ‘of the immutable substance of things,’ and so forth, is not materialism, but metaphysical, i.e., anti-dialectical, materialism ...
In order to present the question in the only correct way, that is, from the dialectical materialist standpoint, we must ask: Do electrons, ether and so on exist as objective realities outside the human mind or not? The scientists will also have to answer this question unhesitatingly; and they do invariably answer it in the affirmative, just as they unhesitatingly recognise that nature existed prior to man and prior to organic matter. Thus, the question is decided in favour of materialism, for the concept matter, as we already stated, epistemologically implies nothing but objective reality existing independently of the human mind and reflected by it.
... Dialectical materialism insists on the approximate, relative character of every scientific theory of the structure of matter and its properties; it insists on the absence of absolute boundaries in nature. ...
However bizarre from the standpoint of ‘common sense’ the transformation of imponderable ether into ponderable matter and vice versa may appear, however ‘strange’ may seem the absence of any other kind of mass in the electron save electromagnetic mass, however extraordinary may be the fact that the mechanical laws of motion are confined only to a single sphere of natural phenomena and are subordinated to the more profound laws of electromagnetic phenomena, and so forth - all this is but another corroboration of dialectical materialism ...”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’
Lenin describes how properties of matter which had previously seemed “absolute, immutable”, like mass, were now turning out not to be so. He makes clear that this shouldn’t come as any surprise – nor as any threat - to anyone looking at scientific developments in a dialectical manner, a manner which “insists on the absence of absolute boundaries in nature”. The only question which a dialectical materialist will insist upon, however, is the existence, in whatever new ways we model it, of an “objective reality existing independently of the human mind”.
Lenin’s analysis in these two chapters of Materialism and Empirio-Criticism, makes clear that he was adamant that materialism should never dogmatically reject new models of reality “however bizarre from the standpoint of ‘common sense” they might seem.
That’s why I believe that, faced with the experimental evidence for the far from ‘common-sense’ predictions of quantum mechanics and general relativity, Lenin would have welcomed these new scientific theories as yet deeper explanations of the nature of objective reality.
“... While yesterday the profundity of this knowledge did not go beyond the atom, and today does not go beyond the electron and ether, dialectical materialism insists on the temporary, relative, approximate character of all these milestones in the knowledge of nature gained by the progressing science of man”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’
‘Straying into Idealism’
So was Lenin a lone voice seeking to maintain a materialist outlook amongst those supporting the ‘new' physics? Far from it. Lenin points to Rey’s analysis which had concluded that the “vast majority” of physicists still retained a “mechanistic or neo-mechanistic” [i.e. an essentially materialist] outlook, including scientists such as “Kirchhoff, Helmholtz, Thomson (Lord Kelvin), Maxwell - among the older physicists - and Larmor and Lorentz among the modern physicists”. [‘Materialism and Empirio-Criticism’, Chapter Five: ‘1. The Crisis in Modern Physics’].
However, Lenin also believed that some other scientists were indeed ‘straying into idealism’. Why? In his view, it was, in part, an overreaction to the earlier ‘mechanist’ materialism (the one Rovelli accuses Lenin of supporting!) that refused to countenance that the old ‘Newtonian’ model of the universe no longer offered a sufficient explanation of the latest scientific discoveries.
“It is mainly because the physicists did not know dialectics that the new physics strayed into idealism. They combated metaphysical (in Engels’ .. sense of the word) materialism and its one-sided ‘mechanism,’ and in so doing threw the baby out with the bath-water.
Denying the immutability of the elements and the properties of matter known hitherto, they ended by denying matter, i.e., the objective reality of the physical world. Denying the absolute character of some of the most important and basic laws, they ended by denying all objective law in nature and in declaring that a law of nature is a mere convention, ‘a limitation of expectation,’ ‘a logical necessity,’ and so forth. Insisting on the approximate and relative character of our knowledge, they ended by denying the object independent of the mind and reflected approximately-correctly and relatively-truthfully by the mind ... “.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Five: ‘2. “Matter has Disappeared” ’
Lenin cites Henri Poincaré as an example. This French physicist had undoubtedly made significant contributions to Lorentz’s theory and was perhaps the first physicist to postulate that the speed of light has to be taken as being constant, a key concept underlying Einstein’s theory of relativity. However, in Lenin’s view, “Henri Poincaré is an eminent physicist but a poor philosopher”. [Materialism and Empirio-Criticism’, Chapter Three: ‘3. Causality and Necessity in Nature’]
From “the ‘ruins’ of the old principles of physics”, Lenin argues that Poincaré had erroneously drawn idealist conclusions, such as: “whatever is not thought, is pure nothing.”
“We are faced, says Poincaré, with the ‘ruins’ of the old principles of physics, ‘a general debacle of principles’ .... We have already seen what epistemological deductions the author draws from this ‘period of doubt’: ‘it is not nature which imposes on [or dictates to] us the concepts of space and time, but we who impose them on nature’; ‘whatever is not thought, is pure nothing’.
These deductions are idealist deductions. The breakdown of the most fundamental principles shows (such is Poincaré's trend of thought) that these principles are not copies, photographs of nature, not images of something external in relation to man's consciousness, but products of his consciousness.”
Lenin, Materialism and Empirio-Criticism’, Chapter Five: ‘1. The Crisis in Modern Physics’
Linked to this philosophical outlook was the idea that “science was nothing but a symbolic formula, a method of notation”, rather than, as Marxism sets out, offering a real, if never perfect, reflection of objective reality. As Lenin puts it, “for Poincaré ... the laws of nature are symbols, conventions, which man creates for the sake of ‘convenience’.”
Lenin also quotes from an English mathematician with a similar philosophical outlook, Karl Pearson: “The laws of science are products of the human mind rather than factors of the external world ... The necessity lies in the world of conceptions and not in the world of perceptions.” [both quotes from ‘Materialism & Empirio-Criticism’, Chapter Three: ‘3. Causality and Necessity in Nature’].
Lenin notes that a similar outlook is adopted by Bogdanov in his ‘Empirio-Monism’. He responds by asserting that materialism believes science is revealing the laws and relationships – however complex or unexpected - underlying the universe, and not that scientific laws are just abstractions derived from human thought.
“Bogdanov wrote (in Empirio-Monism): ‘Laws do not belong to the sphere of experience ... they are not given in it, but are created by thought as a means of organising experience, of harmoniously co-ordinating it into a symmetrical whole ... Empirio-monism is possible only because knowledge actively harmonises experience, eliminating its infinite contradictions, creating for it universal organising forms, replacing the primeval chaotic world of elements by a derivative, ordered world of relations’.
That is not true. The idea that knowledge can ‘create’ universal forms, replace the primeval chaos by order, etc., is the idea of idealist philosophy. The world is matter moving in conformity to law, and our knowledge, being the highest product of nature, is in a position only to reflect this conformity to law”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘3. Causality and Necessity in Nature’
There are some interesting parallels in these formulations with the approach taken by Bohr and Heisenberg to quantum mechanics and the ongoing debates amongst quantum theorists. Does the ‘wave-function’ actually exist or is it just a mathematical ‘convenience’ used to calculate probability?
Lenin again makes clear that concerns about such ‘idealist’ conclusions [even if not expressed in such philosophical terms] were also shared by many scientists who, at root, were grounded by experiment and ‘practice’ in an essentially materialist outlook.
Lenin quotes from an address made by an A. W. Rücker, the president of the physics section of the ‘British Association for the Advancement of Science’, at its meeting held in Glasgow in 1901. Rücker’s speech confronted essentially the same issues that were being raised by Lenin i.e. “whether the hypotheses which are at the base of the scientific theories now most generally accepted are to be regarded as accurate descriptions of the constitution of the universe around us, or merely as convenient fictions”. Rücker concludes that scientists must take the first approach - i.e. materialism.
“The questions still force themselves upon us: ‘Can we argue back from the phenomenon displayed by matter to the constitution of matter itself; whether we have any reason to believe that the sketch which science has already drawn is to some extent a copy, and not a mere diagram of the truth’. ...
Analysing the problem of the structure of matter, Rücker takes air as an example, saying that it consists of gases and that science resolves ‘an elementary gas into a mixture of atoms and ether. ... There are those who cry ‘Halt’; molecules and atoms cannot be directly perceived; they are mere conceptions, which have their uses, but cannot be regarded as realities.’
‘It may be granted that we have not yet framed a consistent image either of the nature of the atoms or of the ether in which they exist, but I have tried to show that in spite of the tentative nature of some of our theories, in spite of many outstanding difficulties, the atomic theory unifies so many facts, simplifies so much that is complicated, that we have a right to insist - at all events until an equally intelligible rival hypothesis is produced - that the main structure of our theory is true; that atoms are not merely aids to puzzled mathematicians, but physical realities.’ ”
Lenin, quoting A.W.Rücker, in ‘Materialism and Empirio-Criticism’, Chapter Five: ‘4.The Two Trends in Modern Physics and English Spiritualism’
Given Rovelli’s philosophical outlook, and his determination that the ideas of quantum mechanics gain widespread acceptance, it is perhaps not altogether surprising that he is also guilty of an overreaction to what he thinks, wrongly, is Lenin’s ‘mechanist’ materialism . When Rovelli writes that “reality may be much more complex than the naïve materialism of eighteenth-century physics”, he thinks he is taking aim at Lenin. But, once again, an objective reading of ‘Materialism and Empirio-Criticism’ shows that Lenin was not a dogmatic mechanist but a dialectical materialist.
Mathematical models and material reality
Quantum mechanics was founded on the complex mathematical methods of Heisenberg and Schrödinger. And, as described above by his colleague Petersen, theorists like Bohr were content for quantum physicists to essentially limit their analyses to the mathematics, to an “abstract quantum physical description” rather than “to think that the task of physics is to find out how nature is”.
But this tendency for theoretical physics to rely increasingly on complex mathematical relationships, rather than providing concrete models of the material reality underlying those equations, had already started to concern some scientists and philosophers at the time Lenin was writing in 1909.
Lenin notes Abel Rey’s concern about the tendency of mathematicians working on scientific theories to “reduce them to abstractions as far as possible, to present them in an entirely non-material and conceptual manner”.
He also quotes physicist Ludwig Boltzmann’s warning that “those who believe atomism to have been eliminated by [the mathematical modelling of] differential equations, cannot see the wood for the trees ... If we do not wish to entertain illusions as to the significance of a differential equation ... we cannot doubt that this picture of the world (expressed in differential equations) must again by its nature be an atomic one”. [‘Materialism and Empirio-Criticism’, Chapter Five: ‘5. The Two Trends in Modern Physics and German Idealism’]
“The mathematicians ... have formed too abstract a conception of the science of physics. ... They have done everything to save objectivity, for they are aware that without objectivity there can be no physics. . . . But the complexity or deviousness of their theories nevertheless leaves an uneasy feeling. It is too artificial, too far-fetched, too stilted; the experimenter here does not feel the spontaneous confidence which constant contact with physical reality gives him. ...
The crisis in physics lies in the conquest of the realm of physics by the mathematical spirit. ... Theoretical physics has become mathematical physics. ... the mathematician, accustomed to conceptual (purely logical) elements, which furnish the sole subject matter of his work, and feeling himself cramped by crude, material elements, which he found insufficiently pliable, necessarily always tended to reduce them to abstractions as far as possible, to present them in an entirely non-material and conceptual manner, or even to ignore them altogether. The elements, as real, objective data, as physical elements, so to speak, completely disappeared. There remained only formal relations represented by the differential equations”.
Lenin, quoting Abel Rey, in ‘Materialism and E-C’, Chapter Five: ‘8.”Physical” Idealism’
As also noted earlier, no lesser a scientist than Albert Einstein voiced a similar concern that a purely statistical model of the world was insufficient and that mathematical models needed to also explain the nature of underlying objective reality. That advice surely still holds true for physics today.
Space, Time and “Matter in Motion”
Critics of Lenin, like Rovelli, may argue that my analysis so far has presented a biased picture of Lenin’s thought. They would point to his consistent use of the phrase “matter in motion” throughout ‘Materialism and Empirio-Criticism’ as evidence that Lenin really was the naïve mechanist that he has been accused of being. It is a phrase that might imply that the only scientific models that Lenin could accept would, as Rovelli puts it, be ones where reality “consists only of particles of matter in motion”.
Scientific thought since Lenin’s time has certainly left the phrase, originally taken from Engels, as an outdated way to fully describe the world around us. The now well-tested concept of ‘mass-energy equivalence’, applied for example to nuclear power and to explain the ‘life cycle’ of stars, has meant that we now know that matter can in fact be ‘created’ and ‘destroyed’. General Relativity and Quantum Mechanics have profoundly changed our understanding of matter, space and time.
But Lenin’s use of the phrase “matter in motion” needs to be read in the context of the whole book, throughout which Lenin stresses that there are no ‘immutable’ categories, recognising for example, that the physics of objects travelling at very high velocities was now being refined to go beyond earlier, Newtonian, limits. He recognises that human understanding of matter, space and time will change, and he welcomes every scientific advance as another step towards a full picture of the nature of objective reality in which we exist.
“Human conceptions of space and time are relative, but these relative conceptions go to compound absolute truth. These relative conceptions, in their development, move towards absolute truth and approach nearer and nearer to it. The mutability of human conceptions of space and time no more refutes the objective reality of space and time than the mutability of scientific knowledge of the structure and forms of matter in motion refutes the objective reality of the external world”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘5. Space and Time’
His book notes and welcomes the “amazing” discoveries being made by the science of his time about the nature of matter, such as the electron, discoveries that were presenting new models of nature that were “much more complicated than the old mechanics”. As his response to the debate about ‘disappearing matter’ shows, Lenin was ready to accept to new ways of describing the nature of reality “however bizarre from the standpoint of ‘common sense’ ”.
“The electron is to the atom as a full stop in this book is to the size of a building 200 feet long, 100 feet broad, and 50 feet high ... ; it moves with a velocity as high as 270,000 kilometres per second; its mass is a function of its velocity; it makes 500 trillion revolutions in a second - all this is much more complicated than the old mechanics; but it is, nevertheless, movement of matter in space and time. Human reason has discovered many amazing things in nature and will discover still more, and will thereby increase its power over nature. But this does not mean that nature is the creation of our mind”
Lenin ‘Materialism and Empirio-Criticism’, Chapter Five: ‘4.The Two Trends in Modern Physics and English Spiritualism’
So, Lenin's use of the phrase “matter in motion” needs to be recognised as his shorthand way to describe the objective material reality that, as a materialist, he insisted existed around us, rather than it being simply a product of the human mind. For the time in which he was writing, it wasn’t a bad formula. But, as a dialectical materialist, Lenin was someone who was ready to change his formulas and slogans when they no longer matched reality – whether in politics or science. “Matter in motion” was also a formula that Lenin would have been prepared to change too.
Scientific formulations have to be taken in their historical context, according to the scientific available at that time, rather than looking at them through the perspective of today’s knowledge. However, if that’s true for Lenin, then it’s also true for Mach. And just as it’s wrong to portray Lenin as an inflexible ‘naïve materialist’, it would also be wrong to take Mach out of his historical context, as if he had already developed conceptions about space and time in a way that were fully consistent with today’s science.
Mach’s scientific and philosophical thought was far from the precise analysis provided by Einstein’s 1905 papers. As discussed above, Mach tried to steer a course between materialism and idealism, believing that to ask “whether the world is real or whether we merely dream it, is devoid of all scientific significance.” As Rovelli himself recognises “it was a metaphysics ... of elements and functions”.
Rather than putting forward a clear understanding of ‘relativity’ – i.e. that how we experience space and time alters according to our reference frame – Mach’s understanding was based on ‘relativism’ – i.e. that how we experience space and time alters according to human thought and sensations.
“We read in Mach: ‘Space and time are well ordered systems of series of sensations’ (Mechanics, 3rd German edition). ... According to Mach, it is not man with his sensations that exists in space and time, but space and time that exist in man, that depend upon man and are generated by man. ... He constructs his epistemological theory time and space on the principle of relativism, and that is all. ...
If our notion of space is taken from experience without being a reflection of objective reality outside us, Mach’s theory remains idealistic. The existence of nature in time, measured in millions of years, prior to the appearance of man and human experience, shows how absurd this idealist theory is.”
“ If time and space are only concepts, man, who created them is justified in going beyond their bounds, and bourgeois professors are justified in receiving salaries from reactionary governments for defending the right to go beyond these bounds, for directly or indirectly defending medieval ‘nonsense’. ”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘5. Space and Time’
Lenin wasn’t just critical of Mach’s conception of space and time, he was also critical of that of Bogdanov too. Following the approach of ‘Empirio-Monism’ discussed earlier, Bogdanov sought to base the objectivity of time and space on the fact that ‘social co-ordination’ meant that they had both become generally accepted concepts.
Lenin counters that: “this is absolutely false”, again pointing out that, on this basis, unscientific biblical teaching about creationism and the age of the Earth, generally accepted by millions of believers, could also be categorised as being ‘objective’ truths.
“It is one thing how, with the help of various sense organs, man perceives space, and how, in the course of long historical development, abstract ideas of space are derived from these perceptions; it is an entirely different thing whether there is an objective reality independent of mankind which corresponds to these perceptions and conceptions of mankind. ...
[Bogdanov says in Empirio-Monism that] time, like space, is ‘a form of social co-ordination of the experiences of different people’, the ‘objectivity’ of both lies in their ‘general significance’. This is absolutely false. Religion also has general significance as expressing the social co-ordination of the experience of the greater part of humanity. But there is no objective reality that corresponds to the teachings of religion, for example, on the past of the earth and the creation of the world.
There is an objective reality that corresponds to the teaching of science (although it is as relative at every stage in the development of science as every stage in the development of religion is relative) that the earth existed prior to any society, prior to man, prior to organic matter, and that it has existed for a definite time and in a definite space in relation to the other planets. According to Bogdanov, the various forms of space and time adapt themselves to man’s experience and his perceptive faculty. As a matter of fact, just the reverse is true: our ‘experience’ and our perception adapt themselves more and more to objective space and time, and reflect them ever more correctly and profoundly.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘5. Space and Time’
Lenin acknowledges that Mach and, for example, idealists like Poincaré, were making useful contributions to the ongoing scientific debates about the nature of space and time. However, he insisted that they were in error to suggest that objective reality – in whatever form the latest scientific theories described it - need not exist at all.
Such an approach left room for the idea that something beyond material reality and objective science was needed to explain the nature of the universe. It opened the door to spiritualism and religious explanations that should have no place in modern science.
“It is absolutely unpardonable to confound, as the Machians do, any particular theory of the structure of matter with the epistemological category, to confound the problem of the new properties of new aspects of matter (electrons, for example) with the old problem of the theory of knowledge, with the problem of the sources of our knowledge, the existence of objective truth.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Two: ‘4. Does Objective Truth Exist?’
***
“Poincaré says that the concepts space and time are relative and that it follows ... that ‘nature does not impose them upon us, but we impose them upon nature, for we find them convenient’. ... The views of the English Machist Karl Pearson are quite definite. He says: ‘Of time as of space we cannot assert a real existence: it is not in things but in our mode of perceiving them.’ This is idealism, pure and simple. ... The Machists ... erred in confounding the mutability of human conceptions of time and space, their exclusively relative character, with the immutability of the fact that man and nature exist only in time and space, and that beings outside time and space, as invented by the priests and maintained by the imagination of the ignorant and downtrodden mass of humanity, are disordered fantasies, the artifices of philosophical idealism - rotten products of a rotten social system”.
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘5. Space and Time’
One of the new contributions to science being explored at this time was the application of multi-dimensional mathematics to theoretical modelling. This raised the possibility of space having four or more dimensions, rather than just three. Lenin makes clear that he agrees with Mach that such multi-dimensional calculations provided a valid technique. Interestingly, he also suggests that, in this case, Mach also shared Lenin’s doubts as to whether it could provide a meaningful model of reality.
“In his Mechanics, Mach defends the mathematicians who are investigating the problem of conceivable spaces with n dimensions; he defends them against the charge of drawing ‘preposterous’ conclusions from their investigations. The defence is absolutely and undoubtedly just, but see the epistemological position Mach takes up in this defence. Recent mathematics, Mach says, has raised the very important and useful question of a space of n dimensions as a conceivable space; nevertheless, only three-dimensional space remains the ‘real case’ [‘ein wirklicher Fall’]. In vain, therefore, ‘many theologians who experience difficulty in deciding where to place hell’, as well as the spiritualists, have sought to take advantage of the fourth dimension. Very good! Mach refuses to join company with the theologians and the spiritualists.”
Lenin, ‘Materialism and Empirio-Criticism’, Chapter Three: ‘5. Space and Time’
It would, as we now know, take Einstein to show Lenin - and Mach - that it is in fact possible to conceive of a four-dimensional universe, and one that still exists as an objective reality, as long as ‘time’ was treated as that fourth dimension.
Returning to Rovelli
Rovelli clearly thinks that Lenin’s emphasis on the philosophical divide between ‘materialism’ and ‘idealism’ is unnecessary. In his chapter on Lenin and Bogdanov, he writes that, if materialism is “the belief that a world exists beyond our minds ... then ... even the Pope is a materialist”.
“Lenin defines 'materialism' in his book as the belief that a world exists beyond our minds. If this is the definition of materialism, then Mach is definitely a materialist; we are all materialists. Even the Pope is a materialist. But then, for Lenin, the only acceptable version of materialism is the idea that ‘there is nothing in the world except matter in motion in space and in time', and that we can arrive at 'certain truths' through knowledge of matter. Bogdanov highlights the scientific as much as the historical weakness of these peremptory assertions.
Of course the world is outside of our mind, but things are much more subtle than naïve materialism would have it. The choice is not just between the idea that the world exists only in our minds, and the idea that it consists only of particles of matter in motion.”
Carlo Rovelli, ‘Helgoland’, Chapter V: ‘Aleksandr Bogdanov and Vladimir Lenin’
If Rovelli feels that the advance of science and culture has left little room for philosophical idealism compared to Lenin’s time, all well and good. However, there are still many millions who adhere to literal religious explanations of evolution and other aspects of science. There are billions more who, at the same time as accepting modern science, also hold on to religious faith and the hope that some kind of spiritual existence can be continued outside the material world. While those individual beliefs may provide solace, they can also be used to generate prejudice and to blunt the desire for struggle, in the forlorn hope that there are easier, religious or spiritual, solutions to the world’s problems.
Rovelli would have been more accurate to have said that materialists believe that there is “only” a world that exists beyond our minds. On that basis, no, the Pope is certainly not a materialist.
In the scientific realm, even more so than in Lenin’s time, then, yes, the “vast majority” of scientists, focused as they are on observing the real world around us, will inevitably adopt a materialist outlook, although still being subject to the social and economic pressures arising from capitalist production. However, particularly in the more theoretical aspects of science, such as quantum physics, I believe the dangers of the kind of philosophical ‘agnosticism’ expressed by Bohr and Mach still persist.
Does Rovelli’s ‘relational quantum mechanics’, postulating, as the ‘New Scientist’ puts it, that “there is no such thing as things, only relations between things” nevertheless give one possible model of reality, if one even more ‘bizarre’ than ‘common-sense’ would suggest? Rovelli thinks it does.
“The best description of reality that we have found is in terms of events that weave a web of interactions. 'Entities' are nothing other than ephemeral nodes in this web. Their properties are not determined until the moment of these interactions; they exist only in relation to something else. Everything is what it is only with respect to something else.”
Carlo Rovelli, ‘Helgoland’, Chapter VII: ‘But is It Really Possible?’
Personally, I don’t think Rovelli does himself any favours in ‘Helgoland’ with his whimsical ramblings and partial and sometimes misconceived analysis of other philosophies, not least that of Lenin. His arguments for ‘RQM’ in ‘Helgoland’ would have been more convincing if they had concentrated on experimental evidence and scientific analysis instead.
I have hopefully shown that I know enough about both Marxism and physics, and about the history of science, to demonstrate that Rovelli has misinterpreted much of ‘Materialism and Empirio-Criticism’ (although he wouldn’t be the first person to have done so!). Perhaps if he re-read it with more of an open mind, he might instead find ideas that could be of assistance to quantum theorists.
However, like Lenin, neither do I profess to have sufficient scientific expertise to comment with sufficient insight on the various different models of ‘quantum reality’ presently under debate. As I noted earlier, ‘Helgoland’ lists a number of alternative models. It also gives their different solutions to the ‘Schrödinger’s Cat paradox’, outlined earlier.
The ‘Many Worlds’ interpretation takes Schrödinger’s wave function as being a physical reality, not just a mathematical predictor of probability. ‘Schrödinger‘s Cat’ is therefore accurately described by its wave function as a ‘superposition’ of being ‘alive’ and ‘dead’ at one and the same time. The observer’s own wave function then interacts with that of the cat to create two separate, but both real, alternative worlds. In one, the cat is alive, in the other, the cat is dead.
The ‘Hidden Variables’ interpretation was originally developed by David Bohm, an American scientist who had to leave the US because of the pressure he was put under for his suspected Communist Party membership. This interpretation also recognises the wave function as being a physical reality, and one that guides real particles. They will therefore exist in definite locations, rather than those locations being non-determined. So, in this case, ‘Schrödinger’s Cat’ is definitely either alive or dead.
The ‘Physical Collapse’ interpretation is a third model recognising the wave function as a physical reality. It postulates that the ‘collapse’ of the wave function is not caused by observation but can occur spontaneously. Although this is presumed to happen very infrequently, in the case of large-scale objects, the likelihood of such an occurrence would become much greater. In this model therefore, the wave function of ‘Schrödinger’s Cat’ quickly adopts either the ‘dead’ or ‘alive’ configuration.
‘QBism’ or ‘Quantum-Bayesianism’ takes a different approach. It argues, as Bohr did, that the wave function is not a real entity, just a way to calculate probability. ‘QBism’ doesn’t attempt to go beyond ‘observables’ in order to make further assumptions about the nature of reality. Therefore it argues that it is pointless to ask about the state that ‘Schrödinger’s Cat’ was in before we observed it. Only afterwards, on observation, can we clearly say it has been seen as being either ‘dead’ or ‘alive’.
“QBism holds a drastically instrumental conception of science: the theory gives predictions only about what a subject can see. I think that science is not just about making predictions. It also provides us with a vision of reality, a conceptual framework for thinking about things. ...
If the objective of science was solely to make predictions, Copernicus would not have discovered anything new with respect to Ptolemy. His astronomical predictions are no better than Ptolemy's. But Copernicus found a key with which to rethink everything, to reach a new level of understanding. ...
Instead of seeing the observer as a part of the world, QBism sees the world reflected in the observer. In so doing, it leaves behind naïve materialism, but ends up falling into an implicit form of idealism. The observer himself can be observed. ... I want a theory of physics that accounts for the structure of the universe, that clarifies what it is to be an observer in the universe, not a theory that makes the universe depend on me observing it”.
Carlo Rovelli, ‘Helgoland’, Chapter II: ‘Accepting Indeterminacy’
Rovelli’s ‘RQM’ also takes the wave function as a predictor of probability but with an important difference. Rovelli makes clear that he does believe that science “provides us with a vision of reality, a conceptual framework for thinking about things”. He sees ‘QBism’ (correctly!) as “falling into an implicit form of idealism” and forgets that every ‘observer’ is also ‘observed’. Instead, ‘RQM’ is based on the idea that every object has to be seen in relation to its interaction with every other object. Objects only effectively ‘exist’ to us when we interact with, or ‘observe’, them.
“The world that we observe is continuously interacting. It is a dense web of interactions. Individual objects are the way in which they interact. If there was an object that had no interactions, no effect upon anything, emitted no light, attracted nothing and repelled nothing, was not touched and had no smell... it would be as good as non-existent. To speak of objects that never interact is to speak of something - even if it existed - that could not concern us. It is not even clear what it would mean to say that such objects 'exist'. The world that we know, that relates to us, that interests us, what we call 'reality', is the vast web of interacting entities, of which we are a part, that manifest themselves by interacting with each other. It is with this web that we are dealing.”
Carlo Rovelli, ‘Helgoland’, Chapter III: Relations’
So, for ‘RQM’, ‘Schrödinger‘s Cat’ is well aware whether it is ‘alive’ or ‘dead’. However, it argues that a separate observer sees things differently, because to them the quantum possibilities of the cat being in either state remain. So, RQM accepts probabilistic indeterminacy but adds that the universe consists of a web of interactions where different observers will interact with different outcomes.
‘RQM’ is certainly not without its critics. For example, the Mexican physicists Muciño, Okon and Sudarsky, supporters of the ‘Physical Collapse’ interpretation, have been engaged in debate with Rovelli about what they see as its logical inconsistencies and vague argumentation. They note, for example, that RQM fails to address the question of the ‘measurement problem’ discussed earlier, instead disguising matters with “new words” (reminiscent of Lenin’s criticisms of Mach & Bogdanov).
"RQM’s ‘resolution’ of the traditional tension between unitary evolution and wave function collapse is as obscure and vague as in standard quantum mechanics. The tension is dressed with new words such as ‘any interaction leading to an event’ instead of ‘measurement’ but the problem prevails. ... Rovelli’s attempt to substitute ‘measurements’ by ‘interactions’ does not really solve the ambiguity.”
Muciño, Okon and Sudarsky, ‘A reply to Rovelli’s response”, 2021.
In conclusion, while Rovelli has the advantage of being able to publicise his particular model of quantum theory through a bestselling paperback, it needs to be remembered that ‘Relational Quantum Mechanics’ is but one of several models that are being debated. What’s more, as US Professor John D. Norton noted in the earlier section on thee ‘Einstein-Bohr Debate’, there are still issues that are “quite unresolved in the foundations of quantum theory”. Perhaps Lenin’s advice on scientific thinking in ‘Materialism and Empirio-Criticism’ might still have some relevance after all.
As a final point, it is of course commonplace for socialists to recall Marx’s ‘eleventh thesis’ on Feuerbach that “philosophers have only interpreted the world in various ways, the point, however, is to change it.” I would only add that such a change is not only urgently needed to address the burning issues of poverty, inequality, war and climate change, but also to provide the time and resources to allow humanity to fully develop its understanding of the nature of the universe in which we exist.
Martin Powell-Davies, 18th June 2023.
A pdf of this article can be downloaded from here.
