Engels and Marx had a lifelong interest in natural science. Both saw their politics growing from a materialist world view of which science was an integral part. Science, argued Marx, “underlies all knowledge”. 
Of the two founders of the Marxist tradition, Engels followed science more closely. He planned a major work setting out his approach to science, its history, place in society and the philosophical arguments surrounding it – but never completed it. Notes survive – some complete chapters, others in very rough form – which have been collected together and published as The Dialectics of Nature.  Engels never managed to fully develop his ideas. He was forced to break off work on The Dialectics of Nature to deal with arguments inside the then growing socialist movement. In Germany a now long forgotten professor, Dühring, had become fashionable among sections of the German workers’ movement. Engels was pressed by Marx, who was working on Capital, to write a polemic against Dühring.
This division of labour between the two men was typical, with Engels usually taking on the job of defending their joint views in public debate. Engels did not approach his task with enthusiasm. He wrote to Marx, “It is all very well for you to talk. You can lie warm in bed and study Russian agrarian conditions in particular and rent in general with nothing to disturb you. But I am to sit on the hard bench, swill the cold wine, suddenly interrupt everything again and tackle the boring Dühring.” 
Dühring’s arguments are of little substance and Engels was scornful of what he called Dühring’s “bumptious pseudo-science” in which he “speaks of all possible things and some others as well”.  Nevertheless, Engels took the opportunity in his polemic, known as Anti-Dühring, to lay out the basic world view that he shared with Marx. As Dühring had drawn on science to justify some of his arguments, Engels replied by spelling out some of his own ideas on science. Engels intended to resume work on The Dialectics of Nature, but was prevented from doing so by Marx’s death. Engels found most of his energies then tied up in preparing Marx’s unfinished Capital for publication, and also in meeting the growing demands placed on him to defend Marxism within the socialist movement.
Nevertheless, despite the unfinished nature of Engels’ project, it is possible to gather a fairly clear idea of his arguments about science. Ever since, those views have been the subject of fierce controversy, both among Marxists and between Marxists and those hostile to socialism. In the process Engels’ views have been distorted by both enemies and many would be friends.
The usual charges against Engels are twofold. On the one hand, he is accused of a crude and mechanistic form of materialism. On the other hand, he is charged with using notions drawn from the idealist philosopher Hegel which have no place in a materialist world view. Engels’ critics often manage to attack him for both these faults in the same breath, not noticing the contradiction. In fact the whole thrust of Engels’ writings on science is a polemic against both the views with which his critics tax him.  John Rees deals in detail elsewhere in this book with many of these attacks on Engels.  The aim of this chapter is to lay out what Engels said in his writings on natural science. In doing so I quote Engels’ words extensively and occasionally at length since they have too often been attacked on the basis of crude distortions. Engels’ arguments are then examined to see how they stand up against the enormous developments in natural science in the century since his death.
Engels enthusiastically welcomed every advance in a scientific understanding of the world. He located this attitude in the context of the battle between the two basic ways of understanding the world which have run through human history – materialism and idealism. The basic premise of materialism is that there is an objective world which exists independently of and predates human beings, human ideas and consciousness – or those of any supposed god. Most materialists would also hold that the world has definite ways of behaving, laws, which can be discovered and understood. Materialism, in its various forms, has long been opposed by another approach, idealism. This is the notion that the world is dependent on, has no existence apart from, some idea or consciousness. Most often this has meant some form of religion in which a god or non-physical being was a necessary precondition of all existence.
For most of human history idealism, usually in the form of religion, was the dominant approach in seeking to understand and explain the world. The balance, however, was decisively shifted in favour of materialism by the scientific revolution of the 16th and 17th centuries, associated with figures like Copernicus, Galileo, Kepler and Newton. Engels saw this revolution as intimately connected with the development of modern bourgeois society and the defeat of the old feudal society. It was a turning point in human history, a time when “the dictatorship of the Church over men’s minds was shattered”, the “greatest progressive revolution that mankind had so far experienced”. 
“Natural science”, Engels wrote, “developed in the midst of the general revolution and was itself thoroughly revolutionary.”  The first step in the scientific revolution was the theory put forward in 1543 by Copernicus that the Earth went round the sun and not the other way round. In throwing the Earth and man out of their place at the centre of the universe this marked a fundamental challenge to the old religion dominated view. Kepler went further and showed that the planets all moved not on perfect circular orbits, as established authority decreed, but rather on ellipses. Moreover, Kepler put forward the then revolutionary notion that the motions of the planets and motions of bodies on Earth could both be explained on the basis of the same physical principles. 
Galileo, using the telescope, recently developed for military purposes, shattered many other old established notions by showing that the Earth was not unique in having a moon. Jupiter had several. He found that the sun, in the established view a perfect, unblemished body, had dark spots. He also conducted systematic experiments and was the first to formulate an understanding of acceleration – change of velocity – which was a crucial step in explaining the dynamics of moving bodies. Newton went further still. He showed how all motion, from apples falling from trees to the trajectory of cannonballs and tides on Earth, to the motion of the Moon and all the planets, could be explained on the basis of his famous three laws of motion and the law of gravity. He also invented, along with the philosopher Leibniz, the mathematical calculus. This for the first time enabled processes involving continuous change to be precisely handled by scientists – for example velocity and acceleration.
Galileo and Newton were “giants”, but they were also products of the society they lived in. The problems they thought about and worked on were those thrown up by a society in which the bourgeoisie was expanding its wealth and power, and so transforming the way human beings interacted with nature.
The bourgeoisie’s drive to expand trade and production meant it had a vital interest in understanding and exploiting the natural world. It was this that lay behind the great scientific breakthroughs. Engels, in several of the sections of The Dialectics of Nature which remain as rough notes and sketches, links the development of science to the development of production. “From the very beginning the origin and development of the sciences has been determined by production.”  Engels never had time to spell out his argument, but a flavour of his approach can be gleaned from a few paragraphs:
If, after the dark night of the Middle Ages was over, the sciences suddenly arose anew with undreamt-of force, developing at a miraculous rate, once again we owe this miracle to production. In the first place, following the crusades, industry developed enormously and brought to light a quantity of new mechanical (weaving, clockmaking, milling), chemical (dyeing, metallurgy, alcohol) and physical (spectacles) facts.
This “not only gave enormous material for observation, but also itself provided quite other means for experimenting than previously existed, and allowed the construction of new instruments”. In addition, “geographical discoveries – made purely for the sake of gain and, therefore in the last resort, of production – opened up an infinite and hitherto inaccessible amount of material of a meteorological, zoological, botanical and physiological (human) bearing.” 
Engels saw that scientific developments themselves changed society and production. Equally he understood that science also developed through its own internal dynamic – through attempts to make theories internally and mutually consistent. His point was to emphasise what was often forgotten: “hitherto, what has been boasted of is what production owes to science, but science owes infinitely more to production”.  As so often in his notes on science, Engels is forced to end with a hope he was never able to fulfil, “this to be studied further and in detail and to be developed”. 
Though the scientific revolution was a huge leap forward, it had a peculiar and one sided nature. “What especially characterises this period is the elaboration of a peculiar general outlook, the central point of which is the view of the absolute immutability of nature.”  At the core of this “Newtonian” world view was the notion that “in whatever way nature itself might have come into being, once present it remained as it was as long as it continued to exist.”
The planets and their satellites, once set in motion by the mysterious first impulse, circled on and on in their predestined ellipses for all eternity. [The Earth] has remained the same without alteration from all eternity, or, alternatively, from the first day of creation. The “five continents” of the present day had always existed, and they had always had the same mountains, valleys and rivers, the same climate, and the same flora and fauna, except in so far as change or transplantation had taken place at the hand of man. The species of plants or animals had been established once and for all when they came into existence. 
In contrast to the history of mankind, “which develops in time, there was ascribed to the history of nature only an unfolding in space”.  All change, all development in nature, was denied. And as a result “natural science, so revolutionary at the outset, suddenly found itself confronted by an out and out conservative nature, in which even today everything was as it had been from the beginning and in which – to the end of the world or for all eternity – everything would remain as it had been since the beginning”. 
Though science had challenged religion it was “still deeply enmeshed in theology”.  This static world view meant it often could give no answer to important questions. “How did the innumerable species of plants and animals arise? And how, above all, did man arise, since after all it was certain that he was not present from all eternity?” To such questions “natural science only too frequently answered by making the creator of all things responsible. Copernicus, at the beginning of the period shows theology the door; Newton closes the period with the postulate of a divine first impulse.” 
Scientific developments in the 19th century challenged this static view of nature. These developments were spectacular, almost on a par with those of the years of Galileo and Newton. Too often the impression is given that the basic picture established by Newton underwent little change until the scientific revolution of the early 20th century associated with people like Albert Einstein. Nothing could be further from the truth. Nineteenth century science, growing in the midst of the industrial revolution, transformed our understanding of nature. Above all these developments proved that “nature also has its history in time”,  that everything in nature “does not just exist, but comes into being and passes away”.  This insight is the cornerstone of the whole of Engels’ approach to natural science.
The first breach in the static view of nature “was made not by a natural scientist but by a philosopher”.  The great 18th century German philosopher Immanuel Kant put forward the hypothesis that the Earth and solar system had evolved from a spinning gaseous cloud. Later the French scientist Pierre Laplace developed the scientific details of Kant’s notion. The details of the theory are thought not to be correct today, but it is right in many essential points. What mattered at the time was that, “if the Earth was something that had come into being, then its present geological, geographical and climatic state, and its plants and animals likewise, must be something that had come into being; it must have had a history”. 
This argument soon derived support from another quarter. “Geology arose and pointed out that not only the terrestrial strata formed one after another and deposited one upon another, but also the shells and skeletons of extinct animals and the trunks, leaves and fruits of no longer existing plants contained in these strata.”  The new geology, developed first by Charles Lyell, indicated that “not only the Earth as a whole but also its present surface and the plants and animals living on it possessed a history in time”. 
There remained, however, a contradiction between the new geology, with its view of the changing Earth, and the then assumed constant nature of plants and animals on the Earth. In this context Engels makes the perceptive comment:
Tradition is a power not only in the Catholic Church but also in natural science. For years Lyell himself did not see the contradiction, and his pupils still less. This can only be explained by the division of labour that had meanwhile become dominant in natural science, which more or less restricted each person to his special sphere, there being only a few whom it did not rob of a comprehensive view. 
Meanwhile physics too had undergone enormous developments in the 19th century. New sciences, of heat, electricity and magnetism had grown up alongside the already established understanding of the mechanics and dynamics of material bodies. These advances were intimately connected with the industrial revolution then transforming capitalist society. For instance, thermodynamics, the science of processes involving heat, was developed directly out of attempts to understand the principles behind, and improve the efficiency of, steam engines. 
At first these advances gave rise to a whole series of separate theories with each phenomenon being explained on the basis of a distinct physical, natural force. But in the mid-19th century a series of scientists forged a revolutionary breakthrough. Meyer in Germany and Joule in England first showed that mechanical motion could be transformed into heat and vice versa. Others then showed that both could be transformed into electricity, magnetism and chemical forces. They “proved that all so-called physical forces, mechanical forces, heat, light, electricity, magnetism, indeed even so called chemical force, become transformed into one another under definite conditions without any loss of force occurring”. 
The point was not just that science had demonstrated the transformations, but also that these transformations were law governed. Underlying them all was the principle dubbed the “conservation of energy”, which remains among the most fundamental principles of science. The total amount of energy remained the same but it could be transferred from one form to another. It was another mighty blow against the static world view. “With that,” Engels wrote, “the special physical forces, the as it were immutable ‘species’ of physics, were resolved into variously differentiated forms of the motions of matter, passing into one another according to definite laws.”  Later in the 19th century things were taken further when scientists showed that not only could heat and mechanical motion be transformed into one another, but that heat was in fact nothing more than the greater or lesser mechanical motion of the atoms or molecules of which a body was composed.
Chemistry too had undergone “wonderfully rapid development” and “attacked the old ideas about nature”. Until the 19th century there seemed to be an unbridgeable gulf between “organic” chemistry, that of living organisms, and “inorganic”. Now “the preparation by inorganic means of compounds that hitherto had been produced only in the living organism proved that the laws of chemistry have the same validity for organic as for inorganic bodies, and to a large extent bridged the gulf between inorganic and organic nature.” 
The old world view had come under attack “in the sphere of biological research also”. Biology had undergone a revolutionary transformation which had shattered for ever many of the old notions. “The more deeply and exactly this research was carried on, the more did the rigid system of an immutably fixed organic nature crumble away at its touch.”  These developments culminated in Darwin’s Origin of Species in 1859, and its theory of evolution by natural selection which put an end to the idea of fixed unchanging species. It showed that all species, including humans, had evolved from common ancestors. Engels enthusiastically wrote to Marx, “Darwin, whom I am just reading, is magnificent – there has never been until now so splendid an attempt to prove historical development in nature.” 
In every field Engels pointed out how the old ahistorical, unchanging view of nature had been challenged if not shattered by the results of science in the 19th century. In the new outlook “all rigidity was dissolved, all fixity dissipated, all particularity that had been regarded as eternal became transient”.  At the social level Marx and Engels had argued, in The Communist Manifesto, that in capitalist society “all fixed fast-frozen relations ... are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air.”  In society this was based on capitalism’s “constant revolutionising of production, uninterrupted disturbance of all social conditions”.  Now the same process had pushed science to the point where it had undermined the old static view of nature and shown that change, constant transformation, was built into nature.
This view was not entirely new. In fact many of the great philosophers of classical Greece had such a view. After the one sided static world view born of the scientific revolution, modern science had “once again returned to the mode of outlook 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 [very simple organisms] to man, has its existence in eternal coming into being and passing away, in ceaseless flux, in unresting motion and change”.  But there was an essential difference. “What in the case of the Greeks was a brilliant intuition, is in our case the result of strictly scientific research.” 
The recognition that nature has a history, that everything in nature is subject to change, comes into being and passes out of existence, is the starting point of Engels’ approach. But then it is necessary to understand how such change unfolds.
The first step in all real science is to examine separate phenomena, the “details” of which “the picture of appearances” is made up. “So long as we do not understand these [details], we have not a clear idea of the whole picture.” 
A necessary starting point was that “in order to understand these details we must detach them from their natural or historical connection and examine each one separately, its nature, special causes, effects etc.”  Engels emphasises over and again the importance of this breaking up of nature – gathering, examining and seeking to understand facts about separate aspects of nature – as the first step in building up a real understanding:
The analysis of nature into its individual parts, the grouping of the different natural processes and objects in definite classes ... these were the fundamental conditions of the gigantic strides in our knowledge of nature that have been made during the last four hundred years. 
The same approach remains the basic method by which most science proceeds, and must proceed, today. Both in Engels’ day and today many scientists would argue that this approach is what science is about, and that they have no need of “philosophy” beyond this. But such an approach, often called empiricism, is not enough to understand the whole picture. It has severe inbuilt limitations.
Engels points to how many scientific “empiricists” of his day had fallen prey to all sorts of claims by mystics, spiritualists and mediums. “The shallowest empiricism that spurns all theory and distrusts all thought”, Engels insists, “is the most certain path from natural science to mysticism.” 
Natural scientists believe that they free themselves from philosophy by ignoring it or abusing it ... [but] they cannot make any headway without thought ... [and] hence they are no less in bondage to philosophy, but unfortunately in most cases to the worst philosophy. 
The great danger is of “observing natural objects and processes in isolation, apart from their connection with the vast whole; of observing them in repose not in motion; as constants, not as essentially variables; in their death, not in their life”. 
Things and their mental reflexes, ideas, are isolated, are to be considered one after the other and apart from each other, are objects of investigation fixed, rigid, given once and for all ... a thing either exists or does not exist; a thing cannot at the same time be itself and something else. Positive and negative absolutely exclude one another; cause and effect stand in a rigid antithesis one to the other. 
“At first sight”, says Engels, “this mode of thinking seems to us very luminous because it is that of so called common sense. Only 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.”  He warns that breaking apart, considering separately aspects of nature, “justifiable and 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”. 
Engels gives a series of examples to illustrate the point: “For everyday purposes we know and can say, e.g. whether an animal is alive or not. But upon closer inquiry, we find that this is in many cases, a very complex question ... it is just as impossible to determine absolutely the moment of death, for physiology proves that death is not an instantaneous momentary phenomenon, but a very protracted process.” 
Again even the notion of identity – to talk of this plant, that animal or this person – is frequently misleading.
The plant, the animal, every cell is at every moment of its life identical with itself and yet becoming distinct front itself, by absorption and excretion of substances, by respiration, by cell formation and death of cells, by the process of circulation taking place, in short by a sum of incessant molecular changes which make up life and the sum total of whose results is evident to our eyes in the phases of life – embryonic life, youth, sexual maturity, process of reproduction, old age, death.
The young boy, the mature man and the aged man are the same person, yet they are continually changing and different. “Abstract identity”, Engels says, “suffices for everyday use where small dimensions or brief periods of time are in question; the limits within which it is usable differ in almost every case and are determined by the nature of the object.” 
The point is of more general validity. It is necessary in beginning to detach aspects of nature from the rest, to isolate them from their connections, to focus on their existence, not their coming into being, passing away or transformation. But this can only partially grasp the reality of nature. We construct an understanding based on abstracting from some facets of the totality of nature. This process of abstraction helps us to look beneath surface appearances and see the essence of what is happening. These insights are then reintegrated into the totality from which they have been extracted, the better to explain the original appearance.
One simple example is Newton’s law of gravity. The core notion of this is that all bodies fall at the same rate – they are all accelerated at the same rate by the force of gravity. A consequence of this law is that a feather and a cannonball dropped from a tower will hit the ground at the same time. But we know that in reality a cannonball will hit the ground before a feather. To begin to explain what is really going on is quite difficult. We, like Newton, must abstract from appearances. Put aside the size and shape of the various objects. Put aside the air through which they fall. Imagine – or try to approximately construct – a situation in which we can ignore these factors. Only then can we grasp and formulate the underlying reality of a uniform acceleration due to gravity. And only then can we use that understanding to move back towards and explain the appearances. We can explain the various times at which objects actually hit the ground by showing how air resistance, the shape of an object and so on produce deviations from what would be expected simply on the basis of the underlying natural law.
Engels argues that a similar process underlies all science. The very notions of “matter” and “motion”, for instance, are of precisely this character. He attacks those who fail to see these concepts are abstractions from real experience, and ask about what is “matter as such” or “motion as such”. 
Matter as such and motion as such have not yet been seen or experienced by anyone, but only the various, actually existing material things and forms of motion. Matter is nothing but the totality of material things from which this concept is abstracted, and motion as such nothing but the totality of all sensuously perceptible forms of motion; words like matter and motion are nothing but abbreviations in which we comprehend many different sensuously perceptible things according to their common properties. Hence matter and motion can be known in no other way than by investigation of the separate material things and forms of motion.
Engels gives as an analogy, “We can eat cherries and plums, but not fruit, because no one has so far eaten fruit as such.” 
Abstraction from appearance to understand the underlying essence is always based on focusing on some facets of nature and ignoring others. As a result, any such understanding always breaks down, is shown to be only partially correct, beyond certain limits. It fails to fit reality where what has previously been ignored can no longer be left out of the picture. We will see later how, for example, the 250 year old Newtonian law of gravity broke down in exactly this fashion in the early 20th century. Again, the centuries old notion of matter as billiard-ball-like lumps or particles broke down at the same time and in a similar manner.
Engels insists therefore that a fully rounded understanding which seeks to overcome these problems must be based on seeing “things and their representations, ideas, in their essential connection, concatenation, motion, origin and ending”.  He calls for a “comprehensive view of the interconnections in nature by means of the facts provided by empirical natural science itself”. 
Engels called the approach he was arguing for “dialectical”. (The word derives from the philosophers of ancient Greece and means seeking truth through critical inquiry, disputation and argument.) It is a critique of static, fixed categories usually used in science-categories valid within certain limits, which differ according to the case, but which prove to be inadequate to fully grasp the nature of reality. There was no question for Engels of fitting facts about nature into some preconceived schema. “In every field of science, in natural as in historical science, one must proceed from the given facts ... the interconnections 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.” 
Engels goes on to argue that having understood the details of how particular processes develop in nature a number of key general features can often be seen. He calls these “laws of the dialectic”. They are not laws in the sense of, say, Newton’s law of gravity, but operate at a quite different level of abstraction. They are ways of seeing the underlying pattern of a process of change after having worked out and understood the concrete details of the process concerned.
The first and most important of these is “the transformation of quantity into quality”, which Engels says is “rather obvious”.  Indeed it is, but it is nonetheless important for that. Modern science has shown, Engels argued, “that in nature, in a manner exactly fixed for each individual case qualitative changes can only occur by the quantitative addition or quantitative substraction of matter and motion (so called energy)”. 
He gives a series of examples to illustrate the point. For instance, he takes the example of water (which has often been derided, but is a precise and excellent example). On heating water quantitative change, more or less heat, produces no qualitative change between certain limits. However, at certain critical points – the boiling and freezing points – a similar quantitative change then produces a dramatic qualitative transformation. The water freezes and becomes ice, or boils into steam. This is not just a question of human thought. Water does freeze and boil, did so long before human beings existed and, no doubt, will continue to do so long after we cease to exist.
Engels argues that this pattern – of the transformation of quantitative change into qualitative change at critical points – is a fairly general phenomenon in nature. “Every metal has its temperature of incandescence and fusion, every liquid its definite freezing and boiling point ... every gas has its critical point at which it can be liquified by pressure and cooling.”  He gives a whole string of other examples from science – which demonstrate that he was remarkably well informed of many of the very latest advances in natural science. Chemistry, he argued, “can be termed the science of the qualitative changes of bodies as a result of changed quantitative composition”. 
For instance, “the case of oxygen. If three atoms unite into a molecule instead of the usual two we get ozone, a body which is very considerably different from ordinary oxygen in its odour and reactions”.  And Engels points to the discovery of the periodic table of elements by Mendeleyev, in which he showed that certain qualitative properties of elements are periodic functions of their atomic weights, as further demonstration of how in nature quantitative change is at certain points transformed into qualitative leaps.
Engels noted that “probably the same gentlemen who up to now have decried the transformation of quantity into quality as mysticism and incomprehensible transcendentalism will now declare that it is indeed something quite self-evident, trivial and commonplace, which they have long employed, and so they have been taught nothing new.” Well, Engels replied, “if these gentlemen have for years caused quantity and quality to be transformed into each other, without knowing what they did, then they will have to console themselves with Molière’s Monsieur Jourdain who has spoken prose all his life without having the slightest inkling of it.” 
Engels goes on to argue that change in nature is also often characterised by “the interpenetration of opposites”  or the “motion through opposites which asserts itself everywhere in nature”  or development through “contradictions”. And he argues that a further characteristic typical of processes of change is “the negation of the negation” – development through a new synthesis emerging which surpasses and transforms the elements of the “contradiction”. To see changes in the way Engels describes is for him not a substitute for understanding the “particular process” itself. 
Engels gives a series of examples to illustrate the kind of processes he means. In Anti-Dühring, a polemical work, some of these examples are fairly trite and some are circular processes which do not really demonstrate the qualitative development that Engels claims to be illustrating. But scattered among the notes in The Dialectics of Nature a picture of what he is grappling with can be found. For instance, Engels discusses the question of living organisms, what following the best scientific understanding of his day he calls “albuminous bodies” (today we would talk of bodies based on DNA, RNA and protein molecules). A condition of existence of any living organism is that it “absorbs other appropriate substances from its environment and assimilates them”:
Non-living bodies also change, disintegrate and enter into combinations in the natural course of events, but in doing this they cease to be what they were. A weather worn rock is no longer a rock, a metal which oxidises turns into rust. But what with non-living bodies is the cause of destruction, with albumen is the fundamental condition of existence ... this uninterrupted metamorphosis [which] essentially consists in the constant self-renewal of the chemical constituents of these bodies.
Life therefore consists primarily in the fact that every moment it is itself and at the same time something else; and this does not take place as the result of a process to which it is subjected from without ... on the contrary ... [it] is a self-implementing process which is inherent in, native to, its bearer. 
The first point is about how things maintain their unity, their identity, in the face of external impulses, effects and pressures to change. These pressures “negate” the object (quite literally in the example of rust Engels mentions). But some material objects have the capacity to react quite differently to such pressures – in so far as such an object absorbs these pressures, and in the process may change itself while preserving itself, it “negates the negation”. Indeed, in the second paragraph quoted above, Engels hints at the possibility of self, or internally generated, change – that is, a self contained totality which evolves under the impact of its own internal “contradictions” (though the particular example he uses does not quite fit). Engels himself never fully developed these ideas, but he is trying to grasp the essence of a pattern, or possibility, of a process of change exhibited by some aspects of the natural world. It is not a formula nor is it a substitute for an investigation and explanation of “the particular nature of each individual case”. 
Engels has sometimes been attacked because some of the science he quotes has since been shown to be wrong. For instance, Engels did believe in the ether, a supposed medium filling all space through which light waves propagated. He was also inclined to accept, for example, the doctrine in evolution known as Lamarckism, the notion that, in addition to natural selection, evolution may also be based on the inheritance of acquired characteristics. We should remember, however, that in the first case all scientists of Engels’ day supported the notion of the ether, and in the second case most biologists of Engels’ day, including Darwin, agreed with him on the possible inheritance of acquired characteristics. Both these views have since been shown to be wrong. But it is unfair to attack Engels for sharing views supported by the best scientists of his day. We should also remember that Engels’ writings on science are preliminary thoughts, often rough notes, rather than a fully worked out view. He ends The Dialectics of Nature with, “All this has to be thoroughly revised”. 
Engels insisted, however, that his general approach was backed up by the findings of modern science. “Nature is the proof of dialectics, and it must be said for modern science that it has furnished the proof with very rich materials, increasing daily.”  How does this claim stand up against the developments in science in the 100 years since Engels’ death?
1. Quoted in preface to Engels, The Dialetics of Nature (Moscow, 1982), p.6.
2. The notes which form The Dialectics of Nature were not published until 1927, many years after Engels’ death.
3. H. Sheehan, Marxism and the Philosophy of Science (New Jersey, 1993), p.29. This book is a useful guide to the arguments within the Marxist tradition on science.
4. Ibid., p.30.
5. For instance, far from the rigid, mechanical deterministic view Engels is often attacked for, he time and again attacks such an approach. Indeed this is so much the case that one is often forced to wonder if these critics have ever actually read Engels! Rigid determinism in natural science in the 19th century was best summed up by the French scientist Pierre Laplace. He claimed that the result of modern science was an all embracing determinism in which the past, present and future down to the smallest detail were all equally and completely determined.
Such “determinism”, Engels argued, “tries to dispose of chance by denying it altogether. According to this conception only simple, direct necessity prevails in nature.” He mocks this view: “That a particular pea-pod contains five peas and not four or six, that a particular dog’s tail is five inches long and not a whit longer or shorter, that this year a particular clover flower was fertilised by a bee and another not, and indeed by precisely one particular bee and at a particular time, that a particular windblown dandelion seed has sprouted and another not, that last night I was bitten by a flea at four o’clock in the morning, and not at three or five o’ clock, and on the right shoulder and not on the left calf – these are all facts which have been produced by an irrevocable concatenation of cause and effect, by an unshatterable necessity of such a nature indeed that the gaseous sphere, from which the solar system was derived, was already so constituted that these events had to happen this and not otherwise. With this kind of necessity we likewise do not get away from the theological conception of nature. Whether with Augustine and Calvin we call it the eternal decree of God, or Kismet as the Turks do, or whether we call it necessity, is all pretty much the same.” (The Dialectics of Nature, p.499)
6. H. Sheehan, op. cit., also defends Engels well from some of the attacks he has suffered.
7. F. Engels, The Dialectics of Nature in Marx and Engels, Collected Works (MECW), Vol 25 (London, 1987), p.319.
8. Ibid., p.320.
9. His explanation, which drew on work on magnetism by Gilbert, was wrong, but the attempt was important. Until then a central belief in all explanations of nature was the sharp distinction between the Moon and the Earth and the rest of the heavens, the “sublunary” and “superlunary” spheres in the language of the day. This distinction was based on the authority of Aristotle, who had been adopted by the Catholic Church, the key ideological authority in feudal society, for its own purposes. In the superlunary sphere, the world of the planets and stars, everything was perfect, unblemished and unchanging, everything was supposed to move endlessly in perfect circles. Change, decay, transformation were the preserve of the “corrupt” sublunary sphere, i.e. Earth and its immediate environment. Kepler’s arguments were therefore a challenge to this central doctrine of the old world view. Galileo’s findings with the telescope must also be seen in this context to appreciate their revolutionary nature.
10. Engels, The Dialectics of Nature, MECW, op. cit., p.465.
11. Ibid., p.466.
12. Ibid., p.466.
13. Ibid., p.466. For one period of history Boris Hessen fulfilled Engels’ hope. Hessen’s account of the relationship between the development of Newton’s science and social and production developments is a masterpiece. See The Social and Economic Roots of Newton’s Principia in Science at the Crossroads: Papers presented to the International Congress of the History of Science and Technology, held in London from 29 June to 3 July 1931, by the delegates of the USSR (London, 1971). Hessen disappeared in the Stalinist purges in the USSR in the 1930s.
14. Ibid., p.321.
15. Ibid., pp.321-322.
16. Ibid., p.322.
17. Ibid., p.322.
18. Ibid., p.322.
19. Ibid., p.322. Newton’s theory explained the motion of the planets once they were moving, he required a “first impulse” (i.e. god) to set the whole mechanism in motion.
20. Engels, Anti-Dühring, MECW, Vol 25, op. cit., p.25.
21. Engels, The Dialectics of Nature, MECW, op. cit., p.324.
22. Ibid., p.323.
23. Ibid., p.324.
24. Ibid., p.324.
25. Ibid., p.324.
26. Ibid., p.325.
27. See a description of this process by one of the key founders of thermodynamics in Reflexions on the Motive Power of Fire by Sadi Carnot, translated and edited (with excellent and fascinating notes) by R. Fox (Manchester University Press, 1986).
28. Engels, The Dialectics of Nature, MECW, op. cit.. p.325.
29. Ibid., p.325.
30. Ibid., p.326.
31. Ibid., p.326.
32. Quoted in H. Sheehan, op. cit., p.38.
33. Engels, The Dialectics of Nature, MECW, op. cit., p.327.
34. K. Marx and F. Engels, Communist Manifesto, Marx and Engels, Selected Works, Vol I (Moscow 1977), p.111.
36. Engels, The Dialectics of Nature, MECW, op. cit., p.327.
37. Ibid., p.327.
38. Engels, Anti-Dühring, MECW, op. cit., p.21.
39. Ibid., p.22.
40. Ibid., p.22.
41. Engels, The Dialectics of Nature, MECW, op. cit., p.353.
42. Ibid., p.491.
43. Engels, Anti-Dühring, MECW, op. cit., p.22.
44. Ibid., p.22.
45. Ibid., p.22.
46. Ibid., pp.22-23.
47. Ibid., p.23.
48. Engels, The Dialectics of Nature, MECW, op. cit., p.495.
49. Ibid., p.515.
50. Ibid., pp.515-516.
51. Engels, Anti-Dühring, MECW, op. cit., p.23.
52. Engels, The Dialectics of Nature, MECW, op. cit., p.356.
53. Ibid., pp.342-343. Engels tackles many arguments about what is “scientific method”. In doing so he challenges many of the then fashionable arguments in a way that was decades in advance of his time. This is especially relevant given that at the time of writing Karl Popper, the famous philosopher of science, has recently died. Popper, especially through his Logic of Scientific Discovery, had been one of the most influential philosophers of science of the last few decades, and there is much in his arguments that is important.
Few of those who study or follow Popper have probably ever bothered to read Engels. Popper himself was a bitter – if shallow – opponent of Marxism. It is therefore amusing that many of Popper’s most original insights about science were precisely those to which Engels had pointed. Popper attacked the traditional empiricist view of science as the gradual accumulation of secure facts, with theories then being developed by induction from these facts and verified through experiment. Instead Popper argued that even the most straightforward observation of nature contains irreducible elements of theory – all observation is “theory laden”. Engels makes precisely this point in a sharp attack on empiricism: “However great one’s contempt for all theoretical thought, nevertheless one cannot bring two natural facts into relation with each other, or understand the connection existing between them, without theoretical thought.” (The Dialectics of Nature, p.354)
Again Popper attacked the notion that scientific theories are constructed by induction from empirical facts. Rather he argued that science develops through the formation of bold conjectures, or hypotheses, which may not be based on facts but which can be tested experimentally. Moreover, far from verifying theory, the point of these tests was to falsify wrong theories. Scientific theories had to be open to falsification; hypotheses were to be refuted by experience. Much of this approach can be found in outline in Engels’ work. He called induction “a swindle”. “According to the inductionists, induction is an infallible method. It is so little so that its apparently surest results are every day overthrown by new discoveries.” (Engels, The Dialectics of Nature, p.508) And he gives example after example of how theories had been refuted by new facts. Engels also pointed out the logical problem with induction, in precisely an example found in Popper, that “it does not follow from the continual rising of the sun in the morning that it will rise again tomorrow”. (Engels, The Dialectics of Nature, p.510) And Engels draws the conclusion, “The form of development of natural science, in so far as it thinks, is the hypothesis”, and that science develops as “observational material weeds out these hypotheses”. (The Dialectics of Nature, p.529, emphasis in Engels’ original)
Critics of Engels often argue that dialectics denies the validity of formal logic. This is simply not true. Dialectics is rather a critique of the limits of formal logic. Such logic is invaluable, but is not capable of fully grasping a dynamic, changing world. (It is interesting to note in this context that some logicians today are seeking to develop new kinds of logic based upon the quantum mechanical nature of reality – which does not easily fit the categories of traditional logic.)
In later years Engels’ ideas on dialectics were distorted out of all recognition by official Stalinist philosophers of states like the USSR, China and the old regimes in Eastern Europe. This has sometime led many genuine Marxists who opposed these regimes to be suspicious of talk of “dialectics”. This, however understandable its motives, is mistaken. These regimes turned every aspect of genuine Marxism on its head in a grotesque parody aimed at legitimising their own rule and exploitation of workers. Genuine Marxists have always had to rescue the real meaning of Marxism from such distortions and insist on its continued relevance. The same approach should be adopted with Engels’ arguments on dialectics.
54. Engels, The Dialectics of Nature, MECW, op. cit., p.356.
55. Ibid., p.357.
56. Ibid., p.359.
57. Ibid., p.359.
58. Ibid., p.359.
59. Ibid., p.361.
60. Ibid., p.357.
61. Ibid., p.492.
62. Engels, Anti-Dühring, MECW, op. cit., p.130.
63. Ibid., pp.76-77.
64. Ibid., p.130.
65. Engels, The Dialectics of Nature, in MECW, op. cit., p.587.
66. Engels, Anti-Dühring, MECW, op. cit., p.24.
Last updated on 17.4.2004