We are publishing below an article originally written as part of the ICC's own discussions on the relationship between marxism and science. It aims to bring together some of Marx and Engels thoughts on the subject, with modern scientific and historical analysis of science, and concludes with a brief critical examination of the ideas of Karl Popper.
The text was originally written in the summer of 2009.
The books discussed here, and a note on the authors
Carlo Rovelli: Anaximandre de Milet ou la naissance de la pensée scientifique.
Marx/Engels : Lettres sur les sciences de la nature.
John Gribbin: Science, a history – 1543-2001.
Engels: Dialectics of nature and Anti-Dühring
Karl Popper: The poverty of historicism
Carlo Rovelli is an Italian physicist currently working at Marseille university, mainly in the field of quantum gravity (he was one of those responsible for the development of loop quantum gravity theory in 1988).
John Gribbin is a visiting fellow in Astronomy at the University of Sussex, and a science writer.
Karl Popper is one of the best-known philosophers of science of the 20th century, and as such is a reference for many scientists. One of his major works, The open society and its enemies targeted notably Plato, Hegel and Marx – and he has famously attacked the scientific status of both marxism and psychoanalysis. The open society... being an enormous tome, this text is limited to a slim volume which resumes much of his thinking.
Of Marx and Engels, it was certainly Engels who wrote the most about science (notably in the two works cited above). It is fascinating to read Engels in the light of the history of science described by Gribbin, since this throws light on the remarkable degree to which Engels actually kept in touch with, and was knowledgeable in, the science of his day. Obviously the science itself has moved on, yet Engels still has much to teach us about the way we think about science, and of course about how the scientific method should inform our thinking as marxists.
One of Engels’ main concerns in Dialectics of nature is to show how the laws of nature are themselves dialectical, in other words dominated by the laws of dialectics (transformation of quality into quantity, interpenetration of opposites, the negation of the negation), and that nature has a history. At the time (Engels began preparing the work in 1873), we should remember, many things that we take absolutely for granted today were very recent discoveries or still disputed: Darwin's work on The Origins of Species had been published barely 15 years before (the Descent of Man was only published in 1871, and it seems that Marx and Engels remained unaware of its main message), it was only beginning to be realised that there was no such thing as a “pure gas” (ie a gas that could only exist as a gas), and so on. It is thus very striking to find Engels writing, more than 20 years before the publication of Einstein's theory of relativity in 1905, that matter is only another form of motion. Engels' and Marx's preoccupation with the natural sciences was something that they always considered an important aspect of the development of a materialist view of the world.
What is science?
Like most other questions, we can only address this one historically. Gribbin takes 1543 as his starting point, a year which by a happy coincidence saw the publication of both Copernicus' De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) and Vesalius' De humani corporis fabrica (On the Structure of the Human Body – Vesalius is often referred to as the founder of modern anatomy). Copernicus, Vesalius, and Galileo (born in 1564) all shared a readiness to call into question the accepted authorities of the day – Ptolemaic astronomy in the case of Copernicus and Galileo, Galen’s medical theories in the case of Vesalius.
Gribbin highlights a number of aspects of Galileo’s life and work which represented a critical break with previous thinking about nature, and which lie at the foundations of all the development of science since then. Although doubtless these first scientists did not realise the full implications of the road they were opening up, these aspects are already contained in germ within their thinking:
an understanding that nature must be studied in its own terms, and that nature is not teleological,
an insistence that theory must be validated by experiment,
a realisation that mathematics is the language of nature, that natural laws can be described in the language of mathematics.
Gribbin also points out that the emergence of this new way of thinking was made possible by the advance of technology: in Galileo’s case, the development of glass manufacture which allowed the creation of the first telescopes. This has continued to be the case ever since – old theories have been called into question in part because new technology has made it possible to measure nature’s parameters with ever greater precision (it is no accident that Newton’s achievements coincide with improvements in metallurgy which in turn led to the construction of more accurate clocks, for example) – and this is still the case today.
Until the second half of the 18th century, science remained essentially a way of thinking about the world without any direct effect on the development of technology. Gribbin highlights the work of James Watt (one of the fathers of the steam engine) as the moment when science began to feed its theoretical insights back into the development of technology: Watt was employed at Glasgow University and used the newly emerging understanding of heat and the transformation of water into steam not only to improve on the existing Newcomen engines, but to set up a company which developed steam engines on the basis of the best existing scientific knowledge. From this moment on, we can say that science truly became a productive force in its own right. Indeed, this intimate, dialectical relationship between science and technology (ie production) is a unique feature of capitalist society: capitalism cannot live without a constant revolutionising of its productive apparatus – one reason that decadent capitalism has not (yet) seen the collapse of production and technology that characterised decadent Roman society.
This view of scientific thought’s place in society essentially echoes that of Engels who – to be schematic – makes a clear distinction between three phases of scientific thought: the “brilliant intuition” of the Greeks, the still essentially empirical experimental science that was born out of the Renaissance, and the full flowering of science as a productive force directly related to the development of production that got under way in the 19th century.
For Engels, a true theoretical science (ie one which views the whole natural world in its interconnections, and in its historical movement) could only be born out of the accumulation of empirical knowledge: one-sided empirical natural science is transformed by its own development into a theoretical science. Theoretical propositions must be validated by experiment. 
Since Engels wrote, the scientific outlook on the world has been profoundly changed by the work of Einstein and his successors, the emergence of the theories of general relativity and quantum mechanics. Indeed we can say that Engels’ attempt to develop a “dialectics of nature” has been triumphantly vindicated by the historical process which has produced quantum theory, a theory which indeed claims, or attempts, to englobe the whole of nature in a unified theoretical vision, justified and validated by experiment.
It is worth pausing here for a moment to consider Engels’ view of cosmology. In Anti-Dühring, Engels takes Dühring to task for his notion of a “self-equal state of matter”, since “We still do not know where mechanical force was in that state, and how we are to get from absolute immobility to motion without an impulse from outside, that is, without God”. At the time, and given the existing state of knowledge about the universe, Engels was undoubtedly right to attack Dühring’s tendency to smuggle teleology back into the natural sciences. In fact, this provides us with an interesting example of how it is possible for a correct general theoretical approach to lead to incorrect hypotheses. At the time, nothing was known about the red-shift which has demonstrated that the surrounding galaxies are moving away from us (indeed nobody was yet aware that various “stars” and nebulae where in fact galaxies like our own) and that indeed space itself is expanding. The scientific view of the universe (ie the non-teleological view which has no place for God in any form) saw it as in an eternal more or less steady state: this view was still defended by the British astronomer Fred Hoyle in the 1960s. And yet today, the majority consensus among scientists seems to be that the universe emerged from an infinitely small and dense singularity: this consensus is born not from mysticism, but from the mathematics of quantum mechanics. The singularity is explained as the natural, indeed inevitable, consequence of the random variations in the quantum void predicted by Heisenberg’s uncertainty principle. The advance of science and experimental data has demonstrated that the Big Bang model is currently the best adapted to explaining observed phenomena, while at the same time the development of theoretical and mathematical tools has maintained the basic scientific principle of studying nature on the basis of nature itself.
This brings me, by a rather roundabout route, to re-pose the question: what is science? And it seems to me that we can, and should, view science from two angles: on the one hand, science is a productive force, a social form which has emerged from the development of a critique of religious temporal and spiritual authority by the rising bourgeoisie, the development of technology which made new tools available to natural philosophy, and the constant demands of capitalist production for a more advanced productive apparatus. In the period of decadence, science has also become one of the most vital instruments of war. On the other hand, science is a materialist – non-teleological – way of looking at the world which must aim not only to explain but to predict, in other words to justify its theory through experiment.
Anaximander of Miletos
But – as Engels said – if experimental science began with the Renaissance, the materialist view of the world was born long before that, in ancient Greece. As Carlo Rovelli points out in his study of Thales and Anaximander, and of the society of the Ionian city of Miletos during the first millennium BCE, the materialist outlook is highly atypical: by far the greater part of human history has been dominated by religious explanations of the origins of the world and of man’s place in it. Although Rovelli’s explanation of religious thought is superficial (he visibly understands nothing of Marx, who he cites), his explanation of how materialist thought emerged in Milesian society is far more interesting.
According to Rovelli Anaximander’s importance lies in his “intuitions” (Rovelli explicitly uses the same word as Engels) based on direct observation, but also going beyond observation to seek an underlying principle to the world. Not only does Anaximander propose a model where the heavenly bodies are no longer confined to a dome over a flat earth, but placed at varying distances from a cylindrical earth floating in space, he also proposes the notion of apeiron as the universal constituent of all matter. As Rovelli says, “Anaximander thus proposes that all substances of our common experience can be understood in terms of something else; something which is both natural and foreign to our daily experience. The central intuition here is that in order to explain the world’s complexity, it is useful to postulate, to imagine, the existence of something else, which is not one of the substances we experience directly but which can play the role of an element that unifies all of them”. Anaximander, in fact, sets human thought on the road to quantum mechanics. Rovelli also shows here that intuition is an important element in scientific thought. Experiment and observation are critical, but they cannot take place without the presence of a hypothesis whose validity they are supposed to test, and the hypothesis necessarily precedes the experiment (though of course the hypothesis may itself be the result of previous experiment or observation).
Rovelli goes on to pose the question of how Anaximander’s thought arose in Miletos: what was specific about Milesian society, and later Greek society, that made possible those “brilliant intuitions” that lay the basis for materialist thinking? When we see the answers that Rovelli gives to this question, one can hardly help wondering whether he is not a reader of the International Review, so close are his ideas to those expressed in the article on the Culture of debate. Let us just highlight briefly some of his main points.
Firstly, there is the importance of Miletos as a trading city, in other words a place where many different cultures and strands of thought came together. Amongst these different cultures Egypt played a particular role since it forced the Greeks to recognise that those outside Greek culture were not “barbarians”, indeed that there existed a civilisation whose antiquity was greater than their own legends. All this helped to liberate thinkers like Thales and his successors from their own religious and social prejudices.
The development of trade in turn led to the emergence of a new social structure which destroyed the dominance of the previous aristocratic or oligarchic rule to replace them with a democracy, where decisions are taken by majority vote after discussion. This capacity for debate is in itself a social discovery: “The cultural basis for the birth of science is thus also the basis for the birth of democracy: the discovery of the effectiveness of criticism and dialogue, between equals. Anaximander, who openly criticises his master Thales, does nothing other than transfer onto the terrain of knowledge the common practice of Miletos’ agora: not to approve uncritically and reverentially the god, demi-god, or lord of the moment, but to criticise the magistrate. Not out of lack of respect, but out of an awareness that a better proposal may always exist (...) This is the discovery in the domain of knowledge: that allowing criticism to take its course, and ideas to be called into question, giving the right to speak to all and taking every proposal seriously, does not lead merely to sterile cacophony. On the contrary, it makes it possible to put aside hypotheses that do not work, and to allow better ideas to emerge” (p97).
Rovelli insists on the difference between Anaximander – who challenged the teachings of his master Thales – and the Chinese savants whose main concern was to build and comment on the works of the masters. Anaximander both built on the ideas of Thales and subjected them to criticism, contrary to the Chinese practice (this goes along with a frequent insistence by Gribbin, that whatever the role played by men of genius such as Newton, science is fundamentally incremental, a collective activity of humanity as a whole).
The ability to criticise the ideas of others also implies a willingness to subject one’s own ideas to criticism and debate. But as Rovelli points out, it is the sign of an idea’s strength, not weakness, that it can be called into question. When we are confident in our ideas, in our theories, then we cannot be afraid of debating them – if debate reveals weaknesses or gaps in this or that aspect of a theory then the theory itself can only be strengthened. And even if the theory itself turns out to be wrong (for example, Copernicus’ theory that the sun was at the centre of the universe), by posing the right questions it will have allowed debate to go forwards and the sum of knowledge to increase.
Rovelli writes “in praise of uncertainty”. Science can never take the theories of today as the final “truth”, they are only the best available at any given moment – and we must live with the awareness that we do not know everything, that maybe it will never be possible for mankind to know everything.
Karl Popper and The poverty of historicism
It would need a text in itself to examine Popper’s ideas, and subject them to criticism. Such a text will be necessary if we want to treat the question of science seriously since Popper is the reference for scientific epistemology: no scientist talking about method will feel unable to refer to Popper. Perhaps his most important idea (at least the most commonly known), is the principle that to be scientific, a theory or hypothesis must be open to invalidation. In other words it must be possible to prove the theory false experimentally. While a hypothesis may attain the status of a theory (or even a “strong theory”) if it proves able to make enough positive predictions, it can never attain the status of “truth” since one contradictory observation or experiment is always enough to overturn the theory. This does not amount to pure empiricism: “I believe that theories are prior to observations as well as to experiment in the sense that the latter are significant only in relation to theoretical problems” (p90).
Up to a point, this vision of scientific thought can be of value, especially in the field of science itself and in the reflection on experimental procedure. It is not, however, complete. Two brief examples, both drawn from La Recherche n°433 in which several articles are devoted to problems of cosmology and the theory of the “multiverse”, can illustrate this point. The various theories of the existence of multiple universes are certainly materialist, and they are certainly scientific in the sense that they are built on some of the current models of the nature of matter which have proven experimentally successful. And yet in themselves, they cannot be tested since if multiple universes exist they are inherently inaccessible to us. Even if we stick to the known universe, it is impossible to test experimentally theories as to the internal structure of black holes, since the very nature of black holes is that no information can escape from them.
In fact, a critique of Popper’s scientific philosophy would have to start with Engels’ critique of metaphysics, in its inability to accommodate historical change. For Popper, it is impossible to have a science of history, or historical development; indeed, it is also impossible to have a law of evolution because “The evolution of life on earth, or of human society, is a unique historical process (...) Its description is not a law, but only a single historical statement (...) we cannot hope to test a universal hypothesis nor to find a natural law acceptable to science if we are forever confined to the observation of one unique process” (p99). Popper is obliged – almost despite himself – to recognise Darwinism as a “scientific hypothesis” because of its demonstrated explanatory power. He also rejects the idea that it is possible to talk of social “laws” in a scientific sense, because historical “laws” are said to be valid only for particular historical periods (Marx and Engels certainly considered that the economic laws of capitalism that they had laid bare only held good for capitalist society), whereas “it is an important postulate of scientific method that we should search for laws with an unlimited realm of validity”.
Popper’s “critique” of marxism is vitiated by the fact that what he understands by "marxism" is in fact nothing but Stalinist ideology. Most notably, Popper seems incapable of seeing the importance that Marx and Engels give to human consciousness as an active factor in the evolution of society – and the factor of consciousness, and humanity’s ability to act consciously on its own history, is one of the most important elements that distinguishes the natural sciences from the materialist, marxist view of history which must take account both of the unconscious factors at work in society, and of the development of conscious human activity on the world: humanity is capable of teleology whereas nature is not.
That said, I do not propose to enter here into a critique of Popper’s social thinking so I will conclude here with a word on his theories of science. The fact that he denies any scientific validity to marxism, to psychoanalytical theory, and even up to a point to Darwinism, reveals the limits of his theoretical approach: a narrow materialism which, when it comes down to it, has little room for a materialist, scientific approach which it may be impossible (at least in the immediate) to test, but which allows science and even society to look at the world in a new way. The example of Copernicus can serve to illustrate this. According to Rovelli, the Copernican theory (the earth revolving around the sun) is in fact inferior to the fully evolved Ptolemaic system, in terms of its predictive power: yet the important thing about the Copernican theory is that for all its faults, it poses the right questions. Others, beginning with Galileo, were to take up the challenge.
 “Thus we have once again returned to the point of view of the great founders of Greek philosophy, the view that the whole of nature, from the smallest element to the greatest, from grains of sand to suns, from protista to men, has its existence in eternal coming into being and passing away, in ceaseless flux, in un-resting motion and change, only with the essential difference that what for the Greeks was a brilliant intuition, is in our case the result of strictly scientific research in accordance with experience, and hence also it emerges in a much more definite and clear form” (Dialectics of Nature).
 “At about the same time, however, empirical natural science made such an advance and arrived at such brilliant results that not only did it become possible to overcome completely the mechanical one-sidedness of the eighteenth century, but also natural science itself, owing to the proof of the inter-connections existing in nature itself between the various fields of investigation (mechanics, physics, chemistry, biology, etc.), was transformed from an empirical into a theoretical science and, by generalising the results achieved, into a system of the materialist knowledge of nature” (Dialectics of Nature, notes for the history of science).
 “We all agree that in every field of science, in natural as in historical science, one must proceed from the given facts, in natural science therefore from the various material forms and the various forms of motion of matter; that therefore in theoretical natural science too the inter-connections are not to be built into the facts but to be discovered in them, and when discovered to be verified as far as possible by experiment” (Dialectics of Nature, the “Old preface to Anti-Dühring”).
 A theory which certainly defies all our ‘common-sense’ views of the world, but as Engels says: “sound common sense, respectable fellow that he is, in the homely realm of his own four walls, has very wonderful adventures directly he ventures out into the wide world of research. And the metaphysical mode of thought, justifiable and even necessary as it is in a number of domains whose extent varies according to the nature of the particular object of investigation, sooner or later reaches a limit, beyond which it becomes one-sided, restricted, abstract, lost in insoluble contradictions. In the contemplation of individual things it forgets the connection between them; in the contemplation of their existence, it forgets the beginning and end of that existence; of their repose, it forgets their motion” (Anti-Dühring).
 Or at least, apparently incorrect, since some scientists continue to prefer some variant of the steady-state model of the universe to the theory of the “Big Bang”.
 One reason for the suspicion aroused by Big Bang theory may be that one of its earliest and greatest proponents was the Belgian catholic priest Georges Lemaître.
 I cannot resist citing here the great French scientist Pierre Simon de Laplace (1749-1827), who answered Napoleon, when the latter asked why his Exposition du système du monde contained no reference to the world’s Creator, with the words “Sire, I found this hypothesis unnecessary”. When the mathematician Lagrange objected that God is a “beautiful hypothesis that explains so many things”, Laplace is said to have answered that “it explains everything, but predicts nothing”.
 Rovelli makes great use of the ideas put forward by Dirk Couprie notably in his book Anaximander in context.
 Rovelli also cites GER Lloyd’s brief comparative study of ancient Greek and Chinese science, The ambitions of curiosity which argues that a major difference between the two cultures lies in the competitive nature of intellectual activity in Greece where different teachers and schools are all vying for influence and students, as opposed to the preoccupation with harmony and process in China, where scholars are above all concerned with developing and influencing the institutions of the state, including the emperor.
 We are talking here about the internal structure of black holes, not about the information which can be gathered, as Stephen Hawking showed, from a black hole’s event horizon.
 As a good bourgeois ideologue, he only recognises the possible “consciousness” of the social scientists themselves – the consciousness of a whole revolutionary class remains a closed book to him.