Outside his specific economic theories, Marx’s main contribution to the social sciences has been his theory of historical materialism. Its starting point is anthropological. Human beings cannot survive without social organisation. Social organisation is based upon social labour and social communication. Social labour always occurs within a given framework of specific, historically determined, social relations of production. These social relations of production determine in the last analysis all other social relations, including those of social communication. It is social existence which determines social consciousness and not the other way around.

Historical materialism posits that relations of production which become stabilised and reproduce themselves are structures which can no longer be changed gradually, piecemeal. They are modes of production. To use Hegel’s dialectical language, which was largely adopted (and adapted) by Marx: they can only change qualitatively through a complete social upheaval, a social revolution or counter-revolution. Quantitative changes can occur within modes of production, but they do not modify the basic structure. In each mode of production, a given set of relations of production constitutes the basis (infrastructure) on which is erected a complex superstructure, encompassing the state and the law (except in a classless society), ideology, religion, philosophy, the arts, morality, etc.

Relations of production are the sum total of social relations which human beings establish among themselves in the production of their material lives. They are therefore not limited to what actually happens at the point of production. Humankind could not survive, i.e. produce, if there did not exist specific forms of circulation of goods, e.g. between producing units (circulation of tools and raw materials) and between production units and consumers. A priori allocation of goods determines other relations of production than does allocation of goods through the market. Partial commodity production (what Marx calls ‘simple commodity production’ or ‘petty commodity production’ – ‘einfache Warenproduktion’) also implies other relations of production than does generalised commodity production.

Except in the case of classless societies, modes of production, centred around prevailing relations of production, are embodied in specific class relations which, in the last analysis, over-determine relations between individuals.

Historical materialism does not deny the individual’s free will, his attempts to make choices concerning his existence according to his individual passions, his interests as he understands them, his convictions, his moral options etc. What historical materialism does state is: (1) that these choices are strongly predetermined by the social framework (education, prevailing ideology and moral ‘values’, variants of behaviour limited by material conditions etc.); (2) that the outcome of the collision of millions of different passions, interests and options is essentially a phenomenon of social logic and not of individual psychology. Here, class interests are predominant.

There is no example in history of a ruling class not trying to defend its class rule, or of an exploited class not trying to limit (and occasionally eliminate) the exploitation it suffers. So outside classless society, the class struggle is a permanent feature of human society. In fact, one of the key theses of historical materialism is that “the history of humankind is the history of class struggles” (Marx, Communist Manifesto, 1848).

The immediate object of class struggle is economic and material. It is a struggle for the division of the social product between the direct producers (the productive, exploited class) and those who appropriate what Marx calls the social surplus product, the residuum of the social product once the producers and their offspring are fed (in the large sense of the word; i.e. the sum total of the consumer goods consumed by that class) and the initial stock of tools and raw materials is reproduced (including the restoration of the initial fertility of the soil). The ruling class functions as a ruling class essentially through the appropriation of the social surplus product. By getting possession of the social surplus product, it acquires the means to foster and maintain most of the superstructural activities mentioned above; and by doing so, it can largely determine their function – to maintain and reproduce the given social structure, the given mode of production – and their contents.

We say ‘largely determine’ and not ‘completely determine’. First, there is an ‘immanent dialectical’, i.e. an autonomous movement, of each specific superstructural sphere of activity. Each generation of scientists, artists, philosophers, theologists, lawyers and politicians finds a given corpus of ideas, forms, rules, techniques, ways of thinking, to which it is initiated through education and current practice, etc. It is not forced to simply continue and reproduce these elements. It can transform them, modify them, change their interconnections, even negate them. Again: historical materialism does not deny that there is a specific history of science, a history of art, a history of philosophy, a history of political and moral ideas, a history of religion etc., which all follow their own logic. It tries to explain why a certain number of scientific, artistic, philosophical, ideological, juridical changes or even revolutions occur at a given time and in given countries, quite different from other ones which occurred some centuries earlier elsewhere. The nexus of these ‘revolutions’ with given historical periods is a nexus of class interests.

Second, each social formation (i.e. a given country in a given epoch) while being characterised by predominant relations of production (i.e. a given mode of production at a certain phase of its development) includes different relations of production which are largely remnants of the past, but also sometimes nuclei of future modes of production. Thus there exists not only the ruling class and the exploited class characteristic of that prevailing mode of production (capitalists and wage earners under capitalism). There also exist remnants of social classes which were predominant when other relations of production prevailed and which, while having lost their hegemony, still manage to survive in the interstices of the new society. This is, for example, the case with petty commodity producers (peasants, handicraftsmen, small merchants), semi-feudal landowners, and even slave-owners, in many already predominantly capitalist social formations throughout the 19th and part of the 20th centuries. Each of these social classes has its own ideology, its own religious and moral values, which are intertwined with the ideology of the hegemonic ruling class, without becoming completely absorbed by that ideology.

Third, even after a given ruling class (e.g. the feudal or semi-feudal nobility) has disappeared as a ruling class, its ideology can survive through sheer force of social inertia and routine (custom). The survival of traditional ancien régime catholic ideology in France during a large part of the 19th century, in spite of the sweeping social, political and ideological changes ushered in by the French revolution, is an illustration of that rule.

Finally, Marx’s statement that the ruling ideology of each epoch is the ideology of the ruling class – another basic tenet of historical materialism – does not express more than it actually says. It implies that other ideologies can exist side by side with that ruling ideology without being hegemonic. To cite the most important of these occurrences: exploited and (or) oppressed social classes can develop their own ideology, which will start to challenge the prevailing hegemonic one. In fact, an ideological class struggle accompanies and sometimes even precedes the political class struggle properly speaking. Religious and philosophical struggles preceding the classical bourgeois revolutions; the first socialist critiques of bourgeois society preceding the constitution of the first working-class parties and revolutions, are examples of that type.

The class struggle has been up to now the great motor of history. Human beings make their own history. No mode of production can be replaced by another one without deliberate actions by large social forces, i.e. without social revolution (or counter-revolution). Whether these revolutions or counter- revolutions actually lead to the long-term implementation of deliberate projects of social reorganization is another matter altogether. Very often, their outcome is to a large extent different from the intention of the main actors.

Human beings act consciously, but they can act with false consciousness. They do not necessarily understand why they want to realise certain social and (or) political plans, why they want to maintain or to change economic or juridical institutions; and especially, they rarely understand in a scientific sense the laws of social change, the material and social preconditions for successfully conserving or changing such institutions. Indeed, Marx claims that only with the discovery of the main tenets of historical materialism have we made a significant step forward towards understanding these laws, without claiming to be able to predict ‘all’ future developments of society.

Social change, social revolutions and counter-revolutions are furthermore occurring within determined material constraints. The level of development of the productive forces – essentially tools and human skills, including their effects upon the fertility of the soil – limits the possibilities of institutional change. Slave labour has shown itself to be largely incompatible with the factory system based upon contemporary machines. Socialism would not be durably built upon the basis of the wooden plough and the potter’s wheel. A social revolution generally widens the scope for the development of the productive forces and leads to social progress in most fields of human activity in a momentous way. Likewise, an epoch of deep social crisis is ushered in when there is a growing conflict between the prevailing mode of production (i.e. the existing social order) on the one hand, and the further development of the productive forces on the other. Such a social crisis will then manifest itself on all major fields and social activity: politics, ideology, morals and law, as well as in the realm of the economic life properly speaking.

Historical materialism thereby provides a measuring stick for human progress: the growth of the productive forces, measurable through the growth of the average productivity of labour, and the number, longevity and skill of the human species. This measuring stick in no way abstracts from the natural preconditions for human survival and human growth (in the broadest sense of the concept). Nor does it abstract from the conditional and partial character of such progress, in terms of social organisation and individual alienation.

In the last analysis, the division of society into antagonistic social classes rejects, from the point of view of historical materialism, an inevitable limitation of human freedom. For Marx and Engels, the real measuring rod of human freedom, i.e. of human wealth, is not ‘productive labour’; this only creates the material pre-condition for that freedom. The real measuring rod is leisure time, not in the sense of ‘time for doing nothing’ but in the sense of time freed from the iron necessity to produce and reproduce material livelihood, and therefore disposable for all-round and free development of the individual talents, wishes, capacities, potentialities, of each human being.

As long as society is too poor, as long as goods and services satisfying basic needs are too scarce, only part of society can be freed from the necessity to devote most of its life to ‘work for a livelihood’ (i.e. of forced labour, in the anthropological/sociological sense of the word, that is in relation to desires, aspirations and talents, not to a juridical status of bonded labour). That is essentially what represents the freedom of the ruling classes and their hangers-on, who are ‘being paid to think’, to create, to invent, to administer, because they have become free from the obligation to bake their own bread, weave their own clothes and build their own houses.

Once the productive forces are developed far enough to guarantee all human beings satisfaction of their basic needs by ‘productive labour’ limited to a minor fraction of lifetime (the half work-day or less), then the material need of the division of society in classes disappears. Then, there remains no objective basis for part of society to monopolise administration, access to information, knowledge, intellectual labour. For that reason, historical materialism explains both the reasons why class societies and class struggles arose in history, and why they will disappear in the future in a classless society of democratically self-administering associated producers.

Historical materialism therefore contains an attempt at explaining the origin, the functions and the future withering away of the state as a specific institution, as well as an attempt to explain politics and political activity in general, as an expression of social conflicts centred around different social interests (mainly, but not only, those of different social classes; important fractions of classes, as well as non-class social groupings, also come into play).

For Marx and Engels, the state is not existent with human society as such, or with ‘organised society’ or even with ‘civilised society’ in the abstract, neither is it the result of any voluntarily concluded ‘social contract’ between individuals. The state is the sum total of apparatuses, i.e. special groups of people separate and apart from the rest (majority) of society, that appropriate to themselves functions of a repressive or integrative nature which were initially exercised by all citizens. This process of alienation occurs in conjunction with the emergence of social classes. The state is an instrument for fostering, conserving and reproducing a given class structure, and not a neutral arbiter between antagonistic class interests.

The emergence of a classless society is therefore closely intertwined, for adherents to historical materialism, with the process of withering away of the state, i.e. of gradual devolution to the whole of society (self-management, self-administration) of all specific functions today exercised by special apparatuses, i.e. of the dissolution of these apparatuses. Marx and Engels visualised the dictatorship of the proletariat, the last form of the state and of political class rule, as an instrument for assuring the transition from class society to classless society. It should itself be a state of a special kind, organising its own gradual disappearance.

We said above that, from the point of view of historical materialism, the immediate object of class struggle is the division of the social product between different social classes. Even the political class struggle in the final analysis serves that main purpose; but it also covers a much broader field of social conflicts. As all state activities have some bearing upon the relative stability of a given social formation, and the class rule to which it is submitted, the class struggle can extend to all fields of politics from foreign policy to educational problems and religious conflicts. This has of course to be proven through painstaking analysis, and not proclaimed as an axiom or a revealed truth. When conducted successfully, such exercises in class analysis and class definition of political, social and even literary struggles becomes impressive works of historical explanation, as for example Marx’s Class Struggles in France 1848-50, Engels’ The German Peasant War, Franz Mehring’s Die Lesssing-Legende, Trotsky’s History of the Russian Revolution, etc.