A strange thing has happened to the reputation of Frederick Engels in the 100 years since his death. For the vast majority of that time both Engels’ allies and his enemies agreed that he was Marx’s alter ego. Indeed, the very expression “alter ego” was Marx’s own description of his relationship to Engels. Most commentators and virtually all Marxists thought that a lifetime of common work, the undeniable and almost undisturbed years of close personal and political co-operation, spoke for themselves. 
But by the 1960s that easy certainty was faced with a sustained challenge. The first cracks in the Cold War consensus were beginning to appear. The growth of CND, the rise of the New Left and, later, opposition to the Vietnam War inevitably produced an enormous increase in interest in radical ideas in general and Marxist ideas, or what passed for Marxist ideas, in particular. This process necessarily led to a reaction against the stifling conformity of reformism and the oppressive legacy of Stalinism. Much of what was said and written marked a rebirth of interest in the genuine Marxist tradition and delivered a long-delayed blow to the reformist and Stalinist traditions.
Yet the reaction against Stalinism was also shaped by Stalinism, in two senses. Firstly, some of those reacting to Stalinism got no further than adopting another variant of Stalinism, either Maoism, or Third Worldism or the ‘reform Communism’ that came to dominate the Western European Communist Parties. Secondly, even those who broke completely with Stalinism tended to confuse elements of the genuine Marxist tradition with the economic determinism characteristic of Stalinism.
All this led to altered perceptions of the Marxist inheritance. Perhaps inevitably, critics began to search the writings of the founders of Marxism for the seeds of Stalinism and failures of reformism. Many of these developments particularly affected students and so fuelled the expansion of academic Marxism. They also coincided with the wider availability of Marx’s early ‘humanist’ writings. A new consensus emerged, both in academic circles and among many on the left, about the nature of Engels’ thought.
One of the first studies to systematically assert a cleavage between Marx’s ideas and those of Engels was George Lichtheim’s Marxism: an Historical and Critical Study, first published in 1961.  Lichtheim insisted that in Marx’s vision “critical thought was validated by revolutionary action”, but in Engels’ scheme “there now appeared a cast-iron system of ‘laws’ from which the inevitability of socialism could be deduced with almost mathematical certainty ... the ‘goal’ was transferred from the here-and-now of conscious activity to a horizon so distant as to be almost invisible.” 
For Marx, Lichtheim claims, “the only nature relevant to the understanding of history was human nature.” Engels therefore broke with Marx when he argued that “historical evolution is an aspect of general (natural) evolution and basically subject to the same ‘laws’.”  This meant that Engels had appropriated Hegel’s heritage quite differently to Marx. Marx had taken from Hegel the importance of self conscious activity in the making of history. In contrast “what really fascinates” Engels “is Hegel’s determinism: his ability to make it appear that nature (and history) follow a pre-ordained course”.  Such a drastic recasting of Marxism inevitably had political consequences:
... determinism in thought making for dogmatism in action. The cast-iron certainty which Engels imported into Marxist thinking found its counterpart at the political level in an unshakable conviction that the stars in their courses were promoting the victory of socialism. 
Consequently, Engels, Kautsky – the leading thinker of the Second International – “and the orthodox school in general” transformed Marxism “from the vision of a unique breakthrough into a doctrine of a casaully determined process analogous to the scheme of Darwinian evolution”. 
Lichtheim’s book rehearses many of the themes that were to become so familiar in other work published over the following 20 years: that Engels replaced Marx’s notion of conscious activity with an empiricist notion of science, that he mistakenly extended Marxism so that it covered the natural as well as the social world, that this inevitably drew him into deterministic and reductionist formulations and that these in turn led him at the end of his life to endorse a reformist political practice on the part of the German Social Democratic Party. And not for the last time the revolutionary, humanist Marx was counterposed to the reformist, determinist Engels by a writer such as Lichtheim who was an opponent of Marxism in theory and a convinced reformist in practice.
After Lichtheim the deluge. Alfred Schmidt’s otherwise more careful and interesting book, The Concept of Nature in Marx, first published in German in 1962, argued that “where Engels passed beyond Marx’s conception of the relation between nature and social history, he relapsed into a dogmatic metaphysic”.  Schmidt also saw a departure from the concerns of the early Marx: “For Engels, nature and man are not united primarily through historical practice; man appears only as a product of evolution and a passive reflection of the process of nature, not however as a productive force”.  By adopting this approach Engels also abandoned Marx’s view of how consciousness is formed:
The movement of thought in Marx is by no means limited to a mere mirroring of the factual. The uncritical reproduction of existing relationships in consciousness has precisely an ideological character for Marx. 
So Schmidt believed that where Marx saw ideas formed in interaction with the material world Engels saw only a crude reflection of the outside world in the brains of human beings, a vulgar “copy theory” of consciousness. By 1969 Lucio Colletti could question, almost in passing:
how far this distortion of Marx’s thought by Kautsky and Plekhanov ...was already prepared, if only in embryo, in some aspects of Engels’s work; and how in general the search for the most general laws of development in nature and history made these attempts a preconstitution of the contamination with Hegelianism and Darwinism. 
He went on to argue that Engels’ influence on the leaders of the Second International was partly a result of “the place given in Engels’ work to philosophical-cosmological development, ‘the philosophy of nature’, in other words, the ‘extension’ of historical materialism into ‘dialectical materialism’.” 
In books as diverse as John Lewis’s The Marxism of Marx (1972), Shlomo Avineri’s widely read textbook The Social and Political Thought of Karl Marx (1970) and Leszek Kolakowski’s sophisticated and profoundly anti-Marxist Main Currents of Marxism (1978) it became an article of faith that Engels had distorted Marx. 
Even authors Paul Walton and Andrew Gamble, who were sympathetic to Marxism at the time they wrote From Alienation to Surplus Value (1972), could conclude that:
[Engels] seems debarred from understanding the real premises of Marx’s method because he seeks to make Marxism an objective science on the model of the natural sciences... he tries to establish the truth of historical materialism by treating human interaction as analogous to the interaction of chemical particles. 
For Gareth Stedman Jones, influenced by Louis Althusser’s structuralism, it was Engels’ “inability adequately to think through the novelty of historical materialism as a science” which “led him to an understandable attempt to fill in the gaps with philosophy – the Hegelian philosophy of his youth”. This not only led to a “lack of any theory of the political instance of social formations” but to Engels embracing “a dangerous implication of the Hegelian theory of knowledge – that everything in reality is, in principle at least, already known”. Thus Engels “unintentionally converted the infant science of historical materialism into the appearance of a finished system, a corpus of absolute knowledge which encompassed the whole of empirical reality”. 
By the early 1970s the pattern was fully established – Engels was the villain. And it did not seem to matter what political or theoretical position a writer set out from – the neo-Kantianism of Colletti, the humanism of Avineri or Schmidt, the Althusserianism of New Left Review contributors – the destination was always the same: Engels was at the root of whatever was wrong with Marxism. With few exceptions,  the argument against Engels had now become a virtual orthodoxy, perhaps best summarised in Norman Levine’s The Tragic Deception: Marx contra Engels (1975) and Terrell Carver’s Marx and Engels, the Intellectual Relationship (1983). Levine states the anti-Engels orthodoxy in its bare essentials:
Engels’ materialism ... was a cold, unremitting, and remorseless system. Men had little impact on fashioning the course of development of history and nature. Rather than being the subject of history, men were basically the passive objects of unrelenting external forces ... Engels’ materialism was mechanistic. 
Naturally, for Levine, it followed that “Engels continuously affirmed the copy theory of knowledge ... there was absolutely no variance, no difference between our comprehension of the external world and the external world itself.” 
Engels’ grave error lay in “making the laws of nature themselves dialectical ... something which Marx himself never attempted”.  Engels “was a unilinear evolutionist”  for whom “causality ... meant additive sequence”  and from whose thought “the notion of human praxis was absent”. Consequently:
Engels’ thought moved from a mechanistic materialist view of the universe to a deterministic view of human history ... it was Engels, not Marx, who was the originator of economic determinism. 
Carver’s work is more qualified and careful in its argument, but it arrives at similar conclusions.  Engels was led to “incorporating the causal laws of physical science and taking them as a model for a covertly academic study of history, ‘thought’ and, somewhat implausibly, current politics”. 
There are many more writers who have argued that Engels was responsible for transforming Marxism into a crude, deterministic philosophy of nature which led to the reformism of the Second International and even Stalinism. To those already quoted could be added Richard Gunn in Marxism Today, Jeff Coulter in Socialist Register, Frederick Bender’s The Betrayal of Marx, Z.A. Jordan’s The Evolution of Dialectical Materialism and many others.  These authors combine different elements of the argument in different ways, and few agree on all the arguments used against Engels, but they say little new.
There are two ways of examining these claims. One is to look at the record of Marx and Engels’ partnership. The second is to study the works in which, both jointly and separately, they elaborated their ideas.
The most remarkable aspect of the view that there was a fundamental divergence between Marx’s theory and Engels’ thought is that it ignores the evidence of their lifelong partnership. Some considerable intellectual contortion is necessary to overcome the elementary biographical facts of Marx and Engels’ lives. For Terrell Carver “the intellectual relationship between the two living men, however, was very much the story of what they accomplished independently”. These accomplishments “were by no means theoretically coincident”. After Marx’s death “Engels moved into an all-powerful role” in which he “invented dialectics and reconstructed Marx’s life and works accordingly”.  Nor is Carver alone in this kind of assertion. It is common coin among Engels’ critics to insist that he codified Marxism as a rigid dialectical philosophy either without Marx’s explicit approval or after his death. Norman Levine argues:
The height of Engels’ career corresponded with the termination of Marx’s life. It is, therefore, entirely consistent that five of Engels’ major works were published in the years closely preceding Marx’s death, or after the termination of Marx’s life. Anti-Dühring appeared in 1878, Socialism: Scientific and Utopian [sic] in 1882, The Origin of the Family, Private Property and the State in 1884, and Ludwig Feuerbach and the End of Classical German Philosophy in 1888. The Dialectics of Nature was first published in 1927 by Riazanov, although the manuscript itself appears to have been completed by 1882. 
Levine makes a more extraordinary claim when he attempts to answer the obvious question of “why basic intellectual differences between the two men did not come to the surface as tangible and real, articulated and acknowledged dispute”. This is a question to which no convincing reply is easily available. Levine’s answer takes us into the ghost world of “the psychological meaning the friendship had for each”. In this realm “Engels chose to tie himself” to Marx because Marx “would also build a place of fame and renown in time for him”; and Marx needed Engels because “Marx did not find the professional and emotional support he needed from his wife”.  But if we leave the territory of Mills and Boon and return to the world of Marx and Engels a very different picture reveals itself.
The first and most striking point about Marx and Engels’ relationship is the strength of the foundations on which it rested. In the 1840s both men arrived at what would later be known as the historical materialist view of the world. But it is by no means the case that Engels simply followed where Marx led. On the vitally important strategic question of the attitude which the pair took to the trade unions it was Engels who blazed the trail. And the entire content of Marx and Engels’ joint work, The Communist Manifesto, was first outlined by Engels alone in Principles of Communism.
On economic questions Engels led the way, even though Marx’s later work in Capital was the decisive contribution. Marx was still extracting himself from the coils of Hegelian philosophy when Engels wrote his Outlines of a Critique of Political Economy. Not only was this the spur to Marx’s own 40 year immersion in economic analysis, it was also the immediate inspiration for Marx’s own transition to a fully materialist class analysis, a process recorded in his Economic and Philosophical Manuscripts of 1844. Indeed, Marx thought Engels’ work “brilliant” and Capital itself carries the subtitle A Critique of Political Economy. Even Carver admits that “Marx’s manuscript notes on Engels’ essay prefigured the course of his lifework” and that “Marx’s Capital was in effect a much elaborated specification of the contradiction discussed by Engels in his Outlines”. 
Having arrived at a common outlook, Marx and Engels jointly authored two key works which elaborated their views, The Holy Family and The German Ideology. They struggled together to win the organisation they were both involved in, the League of the Just, to their ideas, transforming it into the Communist League. The Communist Manifesto was issued in its name. They went on to fight together in the 1848 revolutions – in Engels’ case literally revolver in hand, on the barricades. This then was the foundation of Marx and Engels’ partnership, forged by intense, common intellectual and practical, political work.
The start of Marx’s exile in England and Engels’ life in Manchester unavoidably altered the pattern of their joint work, but it did not end it. Partly, Marx and Engels chose to specialise in different areas. Partly also this differentiation was forced on them by the economic circumstance of Marx’s poverty and Engels’ decision to support his friend while Marx worked on what became Capital. But these new circumstances did not break the intellectual and political trust between them. When Marx had to write articles for newspapers in order to earn some money he never hesitated to put his name to articles which were, in fact, written by Engels.
In the long gestation of Capital Engels was Marx’s constant adviser, either in their almost daily exchange of letters or in conversation when they paid each other visits. Marx consulted Engels on everything from the correct German translation for “gigs” to rent theory, constant and variable capital, surplus value and exploitation. In August 1862 Marx implored Engels to visit him:
I have overthrown so many old views in my critique [i.e. Capital] that I would at least like to consult you over a few points. Writing about the rubbish is tedious for you and me. 
Constant collaboration continued at every stage of the writing of Capital up to and including the reading of the proofs, which Marx largely entrusted to Engels. Even the presentation of Capital bears Engels’ mark. Looking at the proofs, Engels advised Marx that the dialectical points might be made more historically and that Marx had made “a great mistake” in not following the pattern of Hegel’s Encyclopedia with its short sections and many sub-headings.  Marx followed this advice, but ignored other suggestions, “to proceed dialectically in this regard also”, as he joked to Engels in reply. Nevertheless, he insisted, “your satisfaction up to now is more important to me than anything the rest of the world may say of it”.  At the end of it all Marx was in no doubt about his debt to Engels. He wrote:
Without you, I would never have been able to bring the work to completion, and I assure you, it has always weighed on my conscience like an Alp that you have dissipated your splendid energy and let it rust on commercial matters, principally on my account, and into the bargain, still had to participate vicariously in all my minor troubles. 
In this Marx was undoubtedly right, and not just about his debt to Engels. He was right in his assessment of the terrible cost to Engels’ intellectual output during the years in which he worked in Manchester. Although he never complained, Engels knew it too – as is confirmed by the image left to us by Marx’s daughter of Engels joyously coming home from the factory after his last day’s work. When Engels was able to retire he could once again publish major works.
Levine argues that Marx’s death left Engels free to publish his distorted version of Marxism. But even the chronology of publication which Levine gives undermines his own argument. Anti-Dühring was not only published during Marx’s lifetime, the whole project was Marx’s idea. Moreover, Engels read the entire manuscript to Marx and Marx himself wrote one of the chapters on economics. The idea behind the book was to give a defence of Marx’s ideas, so it is hardly likely that such an obviously programmatic statement of his views would have been published without his complete agreement. As Engels noted, “it was self-understood between us that this exposition of mine should not be issued without his knowledge”.  Socialism, Utopian and Scientific was extracted from Anti-Dühring and also published before Marx’s death. The Origin of the Family, Private Property and the State appeared after Marx’s death, but was composed by Engels using the ethnographical notebooks which Marx had written. Ludwig Feuerbach was also published after Marx died but, as if to stress the continuity of the ideas expressed in it with the views of Marx and Engels’ first writings, Engels published Marx’s newly discovered Theses on Feuerbach as an appendix. Engels obviously saw no contradiction between the “humanist” young Marx and the “determinist” older Engels, otherwise he would scarcely have risked such a course, going so far as to describe the Theses as “the brilliant germ” of historical materialism.
Finally, The Dialectics of Nature, which is often used to support distortions of Engels’ work, was never intended for publication and actually bore the inscription, “All this to be revised”, almost as if it were a warning to those who were to take every last word as a finished, polished formulation. Nevertheless, the broad sweep of Engels’ intention was clear from Anti-Dühring, which was written at the same time.
On the key issue of whether Marx endorsed the idea of a dialectic in nature there can be little doubt. In Anti-Dühring Engels specifically quoted Marx’s Capital to this effect: “Here, as in natural science, is shown the correctness of the law discovered by Hegel in his Logic, that merely quantitative changes beyond a certain point pass into qualitative differences.”  And Marx goes on to say in a footnote that: “the molecular theory of modern chemistry ... rests on no other law”.  Marx himself had earlier drawn Engels’ attention to these passages in Capital, explicitly stating his belief that dialectical laws were in evidence in natural science: “in that text I quote Hegel’s discovery regarding the law that merely quantitative changes turn into qualitative changes and state that it holds good alike in history and natural science”.  Also in Capital Marx described exchange relations as operating like “a determining law of nature”. And, despite Carver’s claim that Engels’ admiration for Darwin is evidence of his inclination toward the model of natural science, Marx shared Engels’ assessment: “Darwin’s book is very important and it suits me well that it supports the class struggle in history from the point of view of natural science.” 
So the idea that Marx and Engels developed along separate theoretical paths finds little support in the biographical evidence. Naturally, the rough division of labour which they evolved led to different emphases. Equally naturally, they stressed different aspects of the theory depending on whether they were arguing against empiricists or idealists, system builders or vulgar economists, anarchists or reformists. But in all essentials they were at one. Perhaps nothing conveys this fact as forcefully as the testimony of Laura Marx’s husband, Paul Lafargue:
Engels was, so to speak, a member of the Marx family. Marx’s daughters called him their second father: He was Marx’s alter ego ...
... From their youth they developed together and parallel to each other, lived in intimate fellowship of ideas and feelings and shared the same revolutionary agitation: as long as they lived together they worked in common ... But after the defeat of the 1848 Revolution Engels had to go to Manchester, while Marx was to remain in London. Even so, they continued their common intellectual life by writing to each other almost daily ... As soon as Engels was able to free himself from his work he hurried from, Manchester to London, where he set up his home only ten minutes away from his dear Marx. From 1870 to the death of his friend, not a day went by but the two men saw each other, sometimes at one’s house, sometimes at the other’s ...
Marx appreciated Engels’ opinion more than anybody else’s, for Engels was the man he considered capable of being his collaborator. For him Engels was his whole audience. No effort could have been too great for Marx to convince Engels and win him over to his idea. For instance, I have seen him read whole volumes over and over to find the fact which he needed to change Engels’ opinion on some secondary point ... It was a triumph for Marx to bring Engels round to his opinion.
Marx was proud of Engels. He took pleasure in enumerating to me all his moral and intellectual qualities ... He admired the versatility of his knowledge and was alarmed that the slightest thing should befall him ... 
Marx and Engels were inevitably prey to the limitations of their age. They could not foresee all that natural science would achieve or the problems that would arise in the course of the next century of class struggle. But it is their joint legacy, as the content of their work also demonstrates, on which modern socialism rests.
For Marx and Engels human beings remain part of the natural world from which they have evolved. The human hand, the human brain, the development of language and consciousness have all taken place as part of the processes which dominate the natural world. From their very earliest collaborations Marx and Engels were insistent that no rigid and absolute distinction could be drawn between human history and natural history.
The book in which they first systematically worked out the principles of their approach was The German Ideology. In it Marx and Engels were unambiguous in asserting that human biology and the physical constitution of nature were essential starting points in any attempt to understand the world:
The premises from which we begin are not arbitrary ones, not dogmas, but real premises... They are the real individuals, their activity and the material conditions of their life, both those which they find already existing and those produced by their activity ...
... Thus the first fact to be established is the physical organisation of these individuals and their consequent relation to the rest of nature. 
And, while they elaborate these factors at length, Marx and Engels did spell out that they included “the actual physical nature of man” and “the natural conditions in which man finds himself – geological, orohydrological, climatic and so on”. They argued that “all historical writing must start out from these natural bases and their modification in the course of history through the action of men”. 
Marx and Engels castigate one of their philosophical opponents for going “so far as to speak of ‘the antithesis in nature and history’ as if these were two separate ‘things’ and man did not always have before him an historical nature and a natural history”. 
More than 30 years later Engels returned to the same argument in Anti-Dühring, his broadside against Eugen Dühring, an academic who was gaining a hearing among Marx and Engels’ supporters in Germany. Engels criticises Dühring for “accepting ‘consciousness’, ‘thought’, quite naturalistically, as something given, something opposed from the outset to being, to nature”. And he continues:
If that were so it must seem extremely strange that consciousness and nature, thinking and being, the laws of thought and the laws of nature, should correspond so closely. But if the further question is raised what thought and consciousness really are and where they come from, it becomes apparent that they are products of the human brain and that man himself is a product of nature, which has developed in and along with its environment; hence it is self-evident that the products of the human brain, being in the last analysis also products of nature, do not contradict the rest of nature’s interconnections but are in correspondence with them. 
But the idea that human beings form part of the natural world does not exhaust Marx and Engels’ views on this issue. In the first place, it was the process of development in nature which gave rise to conscious human beings who, from that point on, formed a quite distinct part of nature. This consciousness has material preconditions, and when it has emerged, its further development cannot be separated from the development of the material base on which it rests. In The German Ideology, Marx and Engels outline the preconditions for the emergence of human consciousness:
We must begin by stating the first premise of all human existence and, therefore, of all history, namely, that men must be in a position to live in order to be able to “make history”. But life involves before everything else eating and drinking, housing, clothing and various other things. The first historical act is thus the production of the means to satisfy these needs, the production of material life itself. 
The second prerequisite is “that with the satisfaction of the first need, the action of satisfying and the instrument of satisfaction which has been acquired, leads to new needs; and this creation of new needs is the first historical act.”  The third precondition is that “men who daily re-create their own life, begin to make other men, to propagate their kind: the relation between man and woman, parents and children, the family.” 
Once these elements have developed, and not before, Marx and Engels see the development of a human consciousness which distinguishes human beings from the animal world:
Only now ... do we find that man possesses “consciousness”. But even from the outset this is not “pure” consciousness. The “mind” is from the outset afflicted with the curse of being “burdened” with matter, which here makes its appearance in the form of agitated layers of air, sounds, in short, of language. Language is as old as consciousness, language is practical, real consciousness that exists for other men as well, and only therefore does it exist for me; language, like consciousness, only arises from the need, the necessity, of intercourse with other men. Where it exists it exists for me: the animal does not “relate” itself to anything, it does not “relate” itself at all. For the animal its relation to others does not exist as a relation. Consciousness is, therefore, from the very beginning a social product, and remains so as long as men exist at all. 
And not only is consciousness social, it is also historical. Just as consciousness developed from a long historical process, so its further development is part of a historical process – it develops over time. The consciousness of our very earliest ancestors was only narrowly distinguishable from the instincts of the apes from which they had evolved. It is only with the accumulation of productive forces that human consciousness really becomes distinct from, but not ever separate from or independent of, the natural world.
Neither is this the end of Marx and Engels’ view of the relationship between human history and nature. There is more at stake in this relationship than a historical account of the way in which human history emerges from the history of “raw nature”. Indeed, for Marx and Engels, there is no longer any such thing as “raw nature”: “nature, the nature that preceded human history ... is nature which today no longer exists anywhere (except perhaps on a few Australian coral islands of recent origin)”. 
The nature which does actually exist is one which has been moulded by human beings. The unity of human beings and nature “has always existed in industry and has existed in various forms in every epoch according to the lesser or greater development of industry, and so has the ‘struggle’ of man with nature”. So it is that “in Manchester, for instance”, there are “only factories and machines, where a hundred years ago only spinning wheels and weaving looms were to be seen, or in the Campagna di Roma ... only pasture and swamps, where in the time of Augustus ... nothing but the vineyards and villas of Roman capitalists”. 
Here, then, are Marx and Engels’ early views on the relationship between human beings and the natural world. They stressed the essential unity of human beings and the natural world and the difference between the two and the historical development of this relationship. It was a brilliantly dialectical analysis, a presentation of an internally differentiated totality, a unity of opposites, in which human labour’s interaction with its natural, material environment is the basis of the transformation of both the natural and the human world over time.
As a result of adopting this starting point, Marx and Engels were able to resist the temptation to make a rigid separation between the human sciences and the natural sciences, since materialism is the basis of both, but also to see that human history contained a vital distinguishing feature, conscious labour, which required a distinct approach.
Did Engels depart from this early vision in later life, as his critics insist? Did he abandon the view that conscious human labour was what distinguished human history from natural history? Did he simply revert to a natural science model which he then imported into the received version of Marxism? The quotation from Anti-Dühring, above, indicates that his general attitude had not altered. But in The Part Played by Labour in the Transition from Ape to Man, written in 1876, we can also see that Engels’ approach remained identical. This manuscript, unfinished and unpublished in Engels’ lifetime, forms part of the much derided Dialectics of Nature. Yet the account of the relationship between human beings and the rest of nature reproduces in all essentials the account which Marx and Engels gave in their earliest writings.
The account of evolution, for instance, although much more detailed in the light of the publication of Darwin’s work, still stressed the development of human capacities which resulted from the necessity of meeting the most elementary material needs. Engels’ magnificent account of the development of the human hand, the first human tool, stressed not only the strictly natural, evolutionary development but also the role played by labour in the development of the hand:
Thus the hand is not only the organ of labour, it is also the product of labour. Only by labour, by adaptation to ever new operations, through inheritance of muscles, ligaments, and, over long periods of time, bones that had undergone special development and the ever-renewed employment of this inherited finesse in new, more and more complicated operations, have given the human hand the high degree of perfection required to conjure into being the pictures of a Raphael, the statues of a Thorwaldsen, the music of Paganini. 
But this labour and the power of speech which developed from it “were the two most essential stimuli under the influence of which the brain of the ape gradually changed into that of man”. Yet even now this “was not labour in the proper sense”.  Labour begins, according to Engels, with the making of tools. But even then the fundamental distinction between humans and animals has not yet been made. Animals, says Engels, “change the environment by their activities in the same way, even if not to the same extent, as man does, and these changes ... react upon and change those who made them”.  It is not hard to see here the kind of dialectical process of natural development which Engels thought united the natural with the human world. Nevertheless, he was far from seeing this as a one sided identity. There was, just as in Marx and Engels’ early writings, not only an identity but also a difference between natural and human history. This is why Engels goes on to insist:
But animals exert a lasting effect on the environment unintentionally and, as far as the animals themselves are concerned, accidentally. The further removed men are from animals, however, the more their effect on nature assumes the character of premeditated, planned action directed towards definite preconceived ends. 
And he summarised his attitude in absolutely unambiguous terms:
In short, the animal merely uses its environment, and brings about changes in it simply by its presence; man by his changes makes it serve his ends, masters it. This is the final, essential distinction between man and other animals, and once again it is labour that brings about this distinction. 
This conclusion was not, however, designed to make a final and irrevocable separation between human beings and nature. It was merely a distinction, albeit a vital distinction, within the unity of man and nature. Engels goes on to say that we should not “flatter ourselves overmuch on account of our human victories over nature” since although our conscious designs are often realised in the first place they later bring about results which have unforeseen effects. And so:
... at every step we are reminded that we by no means rule over nature like a conqueror over a foreign people, like someone standing outside nature – but that we, with flesh, blood and brain, belong to nature, and exist in its midst, and that all our mastery of it consists in the fact that we have the advantage over all other creatures of being able to learn its laws and apply them correctly. 
And just in case the final phrases of this quotation should make it seem as if Engels’ critics are in the right when they argue that he had a technocratic approach to social change, one in which science simply paves the way for a better life, Engels concludes:
This regulation [of the natural world] requires something more than mere knowledge. It requires a complete revolution in our hitherto existing mode of production, and simultaneously a revolution in our whole contemporary social order. 
From this account of Marx and Engels’ view of the relationship between human beings and the rest of the natural world it is clear that: (i) at the close of his life Engels held the same general attitude that he held in his early writings, (ii) that this attitude was the same as Marx’s, (iii) that it was not a view which sought to either force human history into the same pattern as natural history or to insist on a rigid separation of the two, and, (iv) that it did try, concretely and empirically, to spell out both what unites human society with, and distinguishes it from, its natural environment.
It was on the basis of their new materialist conception of history that Marx and Engels generalised to produce a dialectical approach to human and natural change. “The dialectic” is often said to be obscure and difficult to understand. Yet its fundamental approach is not hard to grasp, especially against the background of natural evolution and social change outlined in the previous section.
The first basic principle on which the dialectic rests is that the world is in a process of change. Society and nature are not static, neither do they “move in an eternally uniform and perpetually recurring circle”, as Engels says. Instead they undergo a “genuine historical evolution”.  Yet static views of society are still very common today. Through all the hurly-burly of society certain values and institutions are seen as virtually eternal – the family, the market, nationalism, religion, parliamentary democracy and, above all, “human nature”. A dialetical view would recognise that all these ideologies and institutions have a history, that in the past they came into being and in the future they will cease to exist. Marx and Engels developed their own views in criticism of the ideas of the great German philosopher Hegel. But one of Hegel’s great virtues was that he saw “the whole world, natural, historical, intellectual ... as a process, i.e., as in constant motion, change, transformation, development”.  Rejecting static views of the world is, however, only the first step. Trying to understand the way in which this process of change unfolds is the next step.
Here the key is to see all the different aspects of society and nature as interconnected. They are not separate, discrete processes which develop in isolation from each other. Mainstream sociological and scientific thought “has bequeathed us the habit of observing natural objects and processes in isolation, detached from the general context”.  Much of our schooling today still follows this pattern – the development of the arts is separated from that of the sciences, and “technical” subjects are separated from languages, history and geography. Our newspapers and TV news programmes divide the world up in the same artificial way – poverty levels and stock exchange news, wars and company profit figures, strikes and government policy, suicide statistics and the unemployment rate are all reported in their own little compartments as if they are only distantly related, if at all. A dialectical analysis tries to re-establish the real connections between these elements, “to show internal connections”. It tries, in the jargon of dialectics, to see the world as “a totality”, “a unity”.
To see society and nature as an interconnected totality which is in a process of constant change still leaves one vital question unanswered. What makes this whole process develop? Why does it change? There are any number of religious and philosophical theories which try to answer this question by insisting that the motor of change lies outside the historical process – with god, or in the unchanging pattern of human nature or in the eternal features of the human soul. Marx and Engels rejected these approaches as mystical and, literally, supernatural. They insisted that the processes which drove the development of nature and society forward must be internal contradictions, not supersensible entities like god, the soul or, as Hegel had argued, the general essence of human consciousness existing somewhere in the ether beyond the consciousness of actual living human beings.
The relationship between nature and the conscious labour of human beings is, as we have seen, one example of a contradictory totality in a process of change. Since the rise of class society, the struggle between the exploited (the slaves, peasants and wage labourers of ancient Greece and Rome; the peasants and craftsmen of feudal society; the modern working class) and the exploiters (slave owners, landlords and capitalists) provides another example of a series of class contradictions which have led to changes in the totality of the social structure as one great mode of production rises, falls and gives birth to another. In all these cases it is the relationships, the contradictions, between the different parts of the totality which give rise to change. Engels argues:
So long as we consider things as at rest and lifeless, each one by itself, alongside and after each other, we do not run up against any contradictions in them. 
But as soon as we look for the cause of change we are confronted with contradictions – “as soon as contradiction ceases, life, too, comes to an end, and death steps in.” 
These then are the basic terms of the dialectic – contradiction, totality and change. The “three laws” of the dialectic described by Engels cannot be understood without this larger context, since they are ways of specifying how this process of change takes place. Engels’ simplified codification has sometimes led both his followers and his critics to try and isolate the “three laws” from the more general principles of the dialectic. This is a mistake, as the following brief account of those laws makes clear:
i) The unity of opposites. This is simply another way of describing a totality composed of contradictory elements. The totality of capitalist society, for instance, develops in response to the contradiction between the two major classes contained within it, workers and capitalists. The natural and human worlds form, as we have seen, a unity of opposites. Nature and humanity are united, but not identical. It is the relationship between them which shapes the development of each.
ii) The transformation of quantity into quality. This is the process by which small changes of degree eventually result in changes of type. For example, an economic strike in one factory or industry might spread to others until the point is reached where they become a political strike against all employers and the government. Or the working class may suffer a series of individual defeats at the end of which an entirely different type of period in working class history has opened up.
iii) The negation of the negation. This phrase is designed to show how two contradictory (but not necessarily equal) forces react on one another in such a way that the situation which results from their clash both preserves and completely alters them at the same time. Engels follows Marx’s example from Capital. Marx had explained how the change from feudal society to capitalist society had dispossessed peasants and craftsmen of their individual private property, pushing the peasants off the land and depriving craftsmen of the means of production, and consolidated it in the hands of the capitalist class. Capitalism thus expropriated, or negated, individual private property as it had existed under feudalism. A socialist society would “expropriate the expropriators”. It would put means of production in the hands of society collectively and extend “individual ownership to the products, that is, the articles of consumption”. Thus the original negation, of feudal property by capitalist property, is negated once more by a socialist form of ownership. 
Engels immediately recognised that this process, the negation of the negation, might be interpreted in a fatalistic fashion – it might be read as if socialism were inevitable. He insisted that the negation of the negation was not “a mere proof producing instrument”. He went on:
Thus, by characterising the process as the negation of the negation, Marx does not intend to prove that the process was historically necessary. On the contrary: only after he has proved from history that in fact the process has partially occurred, and partially must occur in the future, he in addition characterises it as a process which develops in accordance with a definite dialectical law. 
This was a point which Marx and Engels were to make again and again with regard to the whole dialectical approach, not just the negation of the negation. It was not, they insisted, a substitute for studying the real world, not an equation into which the facts merely had to be slotted, or a pattern into which historical events had to be forced. Each aspect of society had to be studied empirically and in detail. Only then might the unique dialectical pattern be discovered. In each circumstance it could be expected to contain particular features: “Every kind of thing therefore has a peculiar way of being negated in such a way that it gives rise to development, and it is just the same with every kind of conception or idea.” Just playing with dialectical phrases without studying real, empirical developments could only result in “the silliness of the person who adopts such a tedious procedure”. 
Engels approached the distinction between natural and human history in this way. He looked, as we have seen, not just for what unified the two, but also for what made them distinct. Not surprisingly, the distinction between natural evolution and human history reappeared in Engels’ attitude to the dialectic. In The Dialectics of Nature Engels makes an important distinction between the dialectic in human history and that in nature:
In history, motion through opposites is most markedly exhibited in all critical epochs of the foremost peoples. At such moments a people has only the choice between two horns of a dilemma: “either-or!” and indeed the question is always put in a way quite different from that in which the philistines, who dabble in politics in every age, would have liked it put. 
And he goes on to give an example from the 1848 revolutions when “even the German philistine ... found himself in 1849, suddenly, unexpectedly, and against his will confronted with the question: a return to the old reaction in an intensified form, or the continuation of the revolution ...” But on the same page Engels outlines a significantly different pattern of dialectical change in the natural world:
Hard and fast lines are incompatible with the theory of evolution ... “Either-or” becomes more and more inadequate ... For a stage in the outlook on nature where all differences become merged in intermediate steps, and all opposites pass into one another through intermediate links, the old metaphysical method of thought no longer suffices. Dialectics, which likewise knows no hard and fast lines, no unconditional, universally valid “either-or” and which bridges the fixed metaphysical differences, and besides “either-or” recognises also in the right place “both this-and that” and reconciles opposites, is the sole method of thought appropriate in the highest degree to this stage. 
In an important passage in Ludwig Feuerbach and the End of Classical German Philosophy Engels wrote that “dialectics was ... the science of the general laws of motion, both of the external world and of human thought” and that they were “two sets of laws which are identical in substance”. But he explained that the laws were necessarily “different in their expression insofar as the human mind can apply them consciously, while in nature ... these laws assert themselves unconsciously, in the form of external necessity ...”  He also added that, so long as human beings are prevented from consciously controlling the social world it will continue to resemble the natural world in that its laws will operate beyond the will of human beings.
A few pages later Engels returns to and elaborates this point. He notes that human beings do not, in class society, have collective conscious control of their destiny and so “that which is willed happens but rarely”. Consequently, social laws become analogous to those prevailing “in the realm of unconscious nature”. Nevertheless, Engels insists:
In one point, however, the history of the development of society proves to be essentially different from that of nature. In nature – insofar as we ignore man’s reaction on nature – there are only blind, unconscious agencies acting on one another, out of whose interplay the general law comes into operation. Whatever happens ... does not happen as a consciously desired aim. On the other hand, in the history of society the actors are all endowed with consciousness, are men acting with deliberation or passion, working towards definite goals; nothing happens without conscious purpose, without intended aim. 
Such a complex and dialectical approach has only one weakness: it makes it easy for critics to isolate one side of the analysis and then adopt superior airs by correcting Marx and Engels’ supposed shortcomings by presenting the complementary side of the analysis as if it were their own invention.
1. There were voices within the Marxist movement, notably Lukacs and Korsch in the early 1920s, who were critical of this or that aspect of Engels’ writings, but these did not extend to a blanket denial of the unity of Marx and Engels’ approach as did those which arose after 1960.
2. G. Lichtheim, Marxism: an Historical and Critical Study (London, 1961).
3. ibid., p.238.
4. ibid., p.245.
5. ibid., p.253.
6. ibid., p.246.
7. ibid., p.237.
8. A. Schmidt, The Concept of Nature in Marx (London, 1971), p.51.
9. ibid., p.55.
10. ibid., p.56.
11. L. Colletti, From Rousseau to Lenin (London, 1972), p.26.
12. ibid., p.62.
13. For Lewis and Avineri, Engels’ attempt to give a materialist account of nature was a fundamental mistake and a departure from Marx’s method which was exclusively concerned with human society. For Kolakowski: “Engels’ dialectic was formulated under the influence of Darwin’s discoveries ... the main trend of opinion, shared by Engels ... treats human history as a prolongation and a special case of natural history, and assumes that the general laws of nature apply, in specific forms, to the destiny of mankind.”
This attitude was a mistake, and a break with Marx, since “the dialectic, which according to Marx is the unity of theory and practice, cannot be formulated so as to relate to nature in itself as it presupposes the activity of consciousness.” Like earlier writers, Kolakowski sees one consequence of this being the adoption by Engels of a copy theory of consciousness. (Main Currents of Marxism, Vol.I, pp.400-405).
14. P. Walton and A. Gamble, From Alienation to Surplus Value (London, 1976), p.64.
15. G.S. Jones, Engels and the End of Classical German Philosophy, in New Left Review 79, May/June 1973.
16. E.P. Thompson, for instance, defended Engels’ method against distortions by Louis Althusser (see E.P. Thompson, The Poverty of Theory, in The Poverty of Theory and Other Essays, London, 1978), although Thompson’s own approach tended to downplay the material and objective factors in any analysis in a way that Engels himself did not. Thompson’s hostility to party organisation, also a legacy of his experience in the Communist Party, led him to a much more hostile evaluation of Engels’ practical role in the English working class movement (see his Persons and Polemics London, 1994, pp.10-23). S. Timpanaro also mounted a defence of Engels (On Materialism London, 1975). Timpanaro has some valuable insights, but he wrongly tends to accept much of the accusation of “Hegelianism” directed at Engels by his critics.
17. N. Levine, The Tragic Deception, Marx contra Engels (Clio Press, 1975), p.145.
19. ibid., p.152.
20. ibid., p.157.
21. ibid., p.175.
22. ibid., p.157.
23. T. Carver, Marx and Engels, the Intellectual Relationship (Brighton, 1983), p.156: “Engels found his vocation in 1859, rather unfortunately, as a systemising philosopher, setting Marx’s work in an academic and philosophical context, drawing out its implications as a universal methodology, and adding ... a positivist account of natural science.”
24. ibid., p.157.
25. See the survey of anti-Engels literature in H. Sheehan, Marxism and the Philosophy of Science, a Critical History (Humanities Press, 1985), pp.53-60.
26. T. Carver, op. cit., p.151.
27. N. Levine, op. cit., p.233.
28. ibid., p.232. Even if this were a true picture of Marx’s marriage it would be a dubious claim. But, given the enormous pressure of poverty and the family deaths and ill health which accompanied it, Jenny Marx seems to have given her husband a great deal of “professional and emotional support”. This was certainly Marx’s opinion and that of most contemporary witnesses, many of whom stress how close the Marxes’ relationship was.
29. T. Carver, op. cit., pp.36-37.
30. Quoted in J.D. Hunley, The Life and Thought of Friedrich Engels (Yale University Press, 1991), p.135.
31. Engels, Selected Correspondence (Moscow, 1975), p.175.
32. Marx, ibid., p.176
33. ibid., p.138.
34. Engels, quoted in G. Novak, Polemics in Marxist Philosophy (New York, 1978), p.88.
35. Marx, quoted by Engels, Anti-Dühring, in Marx Engels Collected Works (MECW), Vol.25 (London, 1987), p.116. The original is in Marx, Capital, MECW, Vol.35, part III, ch.XI.
36. ibid., p.117.
37. Marx, Selected Correspondence, op. cit., p.177.
38. ibid., p.115.
39. Quoted in D. McLellan (ed.), Karl Marx, Interviews and Recollections (London, 1981), pp.77-78.
40. Marx and Engels, The German Ideology, MECW, Vol.5 (London, 1976), p.31.
42. ibid., pp.39-40.
43. Engels, Anti-Dühring, MECW, op. cit., p.34.
44. ibid., pp.41-42.
45. ibid., p.42.
46. ibid., pp.42-43.
47. ibid., pp.43-44.
48. Marx and Engels, The German Ideology, op. cit., p.40.
50. Engels, The Part Played by Labour in the Transition from Ape to Man, in MECW, Vol.25, op. cit., pp.453-454. Engels’ emphasis.
51. ibid., pp.455-457.
52. ibid., p.459.
53. ibid., p.459.
54. ibid., p.460.
55. ibid., p.461.
56. ibid., p.462.
57. Engels, Socialism, Utopian and Scientific (Peking, 1975), p.67.
58. ibid., p.68.
59. ibid., p.65.
60. Engels, Anti-Dühring, MECW, op. cit., p.111.
61. ibid., p.112.
62. ibid., p.121.
63. ibid., p.124.
64. ibid., p.132. Although it is also true that some of Engels’ own examples, often the ones taken over too literally from Hegel, are misleading. The growth of a grain of barley is not, as Engels suggests, a dialectical development. It does not occur as a result of internal contradictions and is perfectly explicable in ordinary scientific terms. Engels’ other examples, are often brilliant; see for example his description of the relationship between French and Mameluke cavalry (Anti-Dühring, op. cit., p.119).
65. Engels, Dialectics of Nature, MECW, Vol.25, op. cit., p.493.
66. ibid., pp.494-495. Engels’ emphasis.
67. Engels, Ludwig Feuerbach and the End of Classical German Philosophy (Peking, 1976), p.40.
68. ibid., pp.45-46.
Last updated on 17.4.2004