Karl Heinrich Marx (5 May 1818 – 14 March 1883) was a German philosopher, economist, sociologist, historian, journalist, and revolutionary socialist. His ideas played a significant role in the development of social science and the socialist political movement. He published various books during his lifetime, with the most notable being The Communist Manifesto (1848) and Capital (1867 – 1894); some of his works were co-written with his friend, the fellow German revolutionary socialist Friedrich Engels.

Born into a wealthy middle class family in Trier, formerly in Prussian Rhineland now called Rhineland - Palatinate, Marx studied at both the University of Bonn and the University of Berlin, where he became interested in the philosophical ideas of the Young Hegelians. He married Jenny von Westphalen. After his studies, he wrote for a radical newspaper in Cologne, and began to work out his theory of dialectical materialism. Moving to Paris in 1843, he began writing for other radical newspapers. He met Engels in Paris, and the two men worked together on a series of books. Exiled to Brussels, he became a leading figure of the Communist League, before moving back to Cologne, where he founded his own newspaper. In 1849 he was exiled again and moved to London together with his wife and children. In London, where the family was reduced to poverty, Marx continued writing and formulating his theories about the nature of society and how he believed it could be improved, as well as campaigning for socialism and becoming a significant figure in the International Workingmen's Association.

Marx's theories about society, economics and politics, which are collectively known as Marxism, hold that all societies progress through the dialectic of class struggle. He was heavily critical of the current socio - economic form of society, capitalism, which he called the "dictatorship of the bourgeoisie", believing it to be run by the wealthy middle and upper classes purely for their own benefit, and predicted that, like previous socio - economic systems, it would inevitably produce internal tensions which would lead to its self - destruction and replacement by a new system, socialism. Under socialism, he argued that society would be governed by the working class in what he called the "dictatorship of the proletariat", the "workers state" or "workers' democracy". He believed that socialism would, in its turn, eventually be replaced by a stateless, classless society called pure communism. Along with believing in the inevitability of socialism and communism, Marx actively fought for the former's implementation, arguing that both social theorists and underprivileged people should carry out organized revolutionary action to topple capitalism and bring about socio - economic change.

Revolutionary socialist governments espousing Marxist concepts took power in a variety of countries in the 20th century, leading to the formation of such socialist states as the Soviet Union in 1922 and the People's Republic of China in 1949, while various theoretical variants, such as Leninism, Stalinism, Trotskyism and Maoism, were developed. Marx is typically cited, with Émile Durkheim and Max Weber, as one of the three principal architects of modern social science. Marx has been described as one of the most influential figures in human history, and in a 1999 BBC poll was voted the "thinker of the millennium" by people from around the world.

Karl Heinrich Marx was born on 5 May 1818 at 664 Brückergasse in Trier, a town located in the Kingdom of Prussia's Province of the Lower Rhine. His ancestry was Jewish, with his paternal line having supplied the rabbis of Trier since 1723, a role that had been taken up by his own grandfather, Meier Halevi Marx; Meier's son and Karl's father would be the first in the line to receive a secular education. His maternal grandfather was a Dutch rabbi. Karl's father, Herschel Marx, was middle class and relatively prosperous, owning a number of Moselle vineyards; he converted from Judaism to the Protestant Christian denomination of Lutheranism prior to his son's birth, taking on the German forename of Heinrich over Herschel. In 1815, he began working as an attorney and in 1819 moved his family from a five room rented apartment into a ten room property near the Porta Nigra. A man of the Enlightenment, Heinrich Marx was interested in the ideas of the philosophers Immanuel Kant and Voltaire, and took part in agitation for a constitution and reforms in Prussia, which was then governed by an absolute monarchy. Karl's mother, born Henrietta Pressburg, was a Dutch Jew who, unlike her husband, was only semi - literate. She claimed to suffer from "excessive mother love", devoting much time to her family, and insisting on cleanliness within her home. She was from a prosperous business family. Her family later founded the company Philips Electronics: she was great - aunt to Anton and Gerard Philips, and great - great - aunt to Frits Philips.

Little is known about Karl Marx's childhood. He was privately educated until 1830, when he entered Trier High School, whose headmaster Hugo Wyttenbach was a friend of his father. Wyttenbach had employed many liberal humanists as teachers; this angered the government so that the police raided the school in 1832, discovering what they labelled seditious literature espousing political liberalism being distributed amongst the students. In 1835, Karl, then aged seventeen, began attending the University of Bonn, where he wished to study philosophy and literature, but his father insisted on law as a more practical field of study. He was able to avoid military service when he turned eighteen because he suffered from a weak chest. Being fond of alcoholic beverages, at Bonn he joined the Trier Tavern Club drinking society (Landsmannschaft der Treveraner) and at one point served as its co-president. Marx was more interested in drinking and socializing than studying law, and due to his poor grades, his father forced him to transfer to the far more serious and academically oriented University of Berlin, where his legal studies became less significant than excursions into philosophy and history.

In 1836, Marx became engaged to Jenny von Westphalen, a beautiful baroness of the Prussian ruling class — "the most desirable young woman in Trier" — who broke off her engagement with a young aristocratic second lieutenant in order to be with him. Their eventual marriage was controversial for breaking three social taboos of the period; it was a marriage between a daughter of a noble background and a man of Jewish origin as well as being between individuals who belonged to the middle and upper class (aristocracy), respectively, and between a man and an older woman. Such issues were lessened by Marx's friendship with Jenny's father, Baron Ludwig von Westphalen, a liberal thinking aristocrat. Marx dedicated his doctoral thesis to him. The couple married seven years later, on 19 June 1843, at the Pauluskirche in Bad Kreuznach.

Marx became interested in, but critical of, the work of the German philosopher G.W.F Hegel (1770 – 1831), whose ideas were widely debated amongst European philosophical circles at the time. Marx wrote about falling ill "from intense vexation at having to make an idol of a view I detested." He became involved with a group of radical thinkers known as the Young Hegelians, who gathered around Ludwig Feuerbach and Bruno Bauer. Like Marx, the Young Hegelians were critical of Hegel's metaphysical assumptions, but still adopted his dialectical method in order to criticize established society, politics and religion. Marx befriended Bauer, and in July 1841 the two scandalized their class in Bonn by getting drunk, laughing in church, and galloping through the streets on donkeys. During that period, Marx concentrated on his criticism of Hegel and certain other Young Hegelians.

Marx also wrote for his own enjoyment, writing both non - fiction and fiction. In 1837, he completed a short novel, Scorpion and Felix; a drama, Oulanem; and some poems; none of which were published. In 1971, Marx's one act play Oulanem was made available in English by author Robert Payne. According to Payne, the title Oulanem is an anagram for "Manuelo" which is a variant of "Emmanuel" meaning "God is with us". He soon gave up writing fiction for other pursuits, including learning English and Italian.

He was deeply engaged in writing his doctoral thesis, The Difference Between the Democritean and Epicurean Philosophy of Nature, which he finished in 1841. The essay has been described as "a daring and original piece of work in which he set out to show that theology must yield to the superior wisdom of philosophy", and as such was controversial, particularly among the conservative professors at the University of Berlin. Marx decided to submit it instead to the more liberal University of Jena, whose faculty awarded him his PhD based on it.

From considering an academic career, Marx turned to journalism. He moved to the city of Cologne in 1842, where he began writing for the radical newspaper Rheinische Zeitung, where he expressed his increasingly socialist views on politics. He criticized the governments of Europe and their policies, but also liberals and other members of the socialist movement whose ideas he thought were ineffective or outright anti - socialist. The paper eventually attracted the attention of the Prussian government censors, who checked every issue for potentially seditious material before it could be printed. Marx said, "Our newspaper has to be presented to the police to be sniffed at, and if the police nose smells anything un - Christian or un - Prussian, the newspaper is not allowed to appear." After the paper published an article strongly criticizing the monarchy in Russia, the Russian Tsar Nicholas I, an ally of the Prussian monarchy, requested that the Rheinische Zeitung be banned. The Prussian government shut down the paper in 1843. Marx wrote for the Young Hegelian journal, the Deutsche Jahrbücher, in which he criticized the censorship instructions issued by Prussian King Friedrich Wilhelm IV. His article was censored and the newspaper closed down by the authorities shortly after.

In 1843, Marx published On the Jewish Question, in which he distinguished between political and human emancipation. He also examined the role of religious practice in society. That same year he published Contribution to Critique of Hegel's Philosophy of Right, in which he dealt more substantively with religion, describing it as "the opiate of the people". He completed both works shortly before leaving Cologne.

Following the government imposed shutdown of the Rheinische Zeitung, Marx got involved with a new radical newspaper, the Deutsch - Französische Jahrbücher (German - French Annals), which was then being set up by Arnold Ruge, another German socialist revolutionary. The paper was based not in Germany, but in the city of Paris in neighboring France, and it was here that both Marx and his wife moved in October 1843. They initially lived with Ruge and his wife communally at 23 Rue Vaneau, but finding these living conditions difficult, the Marxes moved out following the birth of their daughter Jenny in 1844. Although it was intended to attract writers from both France and the German states, the Deutsch - Französische Jahrbücher was dominated by the latter, with the only non - German writer being the exiled Russian anarcho - communist Mikhail Bakunin. Only one issue was ever published, but it was relatively successful, largely due to the inclusion of Heinrich Heine's satirical odes on King Ludwig of Bavaria, which led to those copies sent to Germany being confiscated by the state's police force.

It was in Paris that, on 28 August 1844, Marx met German socialist Friedrich Engels at the Café de la Régence after becoming interested in the ideas that the latter had expressed in articles written for the Rheinische Zeitung and the Deutsch - Französische Jahrbücher. Although they had briefly met each other at the offices of the Rheinische Zeitung in 1842, it was here in Paris that they began their friendship that would last for the rest of their lives. Engels showed Marx his recently published book, The Condition of the Working Class in England in 1844, which convinced Marx that the working class would be the agent and instrument of the final revolution in history. Engels and Marx soon set about writing a criticism of the philosophical ideas of Marx's former friend, the Young Hegelian Bruno Bauer, which would be published in 1845 as The Holy Family. Although critical of Bauer, Marx was increasingly influenced by the ideas of the other Young Hegelians Max Stirner and Ludwig Feuerbach, but eventually also abandoned Feuerbachian materialism as well.

In 1844 Marx wrote The Economic and Philosophical Manuscripts, a work which covered numerous topics, and went into detail to explain Marx's concept of alienated labor. A year later Marx would write Theses on Feuerbach, best known for the statement that "the philosophers have only interpreted the world, the point is to change it". This work contains Marx's criticism of materialism (for being contemplative), idealism (for reducing practice to theory) and overall, criticizing philosophy for putting abstract reality above the physical world. It thus introduced the first glimpse at Marx's historical materialism, an argument that the world is changed not by ideas but by actual, physical, material activity and practice.

After the collapse of the Deutsch - Französische Jahrbücher, Marx, still living on the Rue Vaneau, began writing for what was then the only uncensored German language radical newspaper in Europe, Vorwärts!. Based in Paris, the paper had been established and was run by many activists connected to the revolutionary socialist League of the Just, which would come to be better known as the Communist League within a few years. In Vorwärts!, Marx continued to refine his views on socialism based upon the Hegelian and Feuerbachian ideas of dialectical materialism, whilst at the same time criticizing various liberals and other socialists operating in Europe at the time. However in 1845, after receiving a request from the Prussian king, the French government agreed to shut down Vorwärts!, and furthermore, Marx himself was expelled from France by the interior minister François Guizot.

Unable either to stay in France or to move to Germany, Marx decided to emigrate to Brussels in Belgium, but had to pledge not to publish anything on the subject of contemporary politics in order to enter. In Brussels, he associated with other exiled socialists from across Europe, including Moses Hess, Karl Heinzen and Joseph Weydemeyer, and soon Engels moved to the city in order to join them. In 1845 Marx and Engels visited the leaders of the Chartists, a socialist movement in Britain, using the trip as an opportunity to study in various libraries in London and Manchester. In collaboration with Engels he also set about writing a book which is often seen as his best treatment of the concept of historical materialism, The German Ideology; the work, like many others, would not see publication in Marx's lifetime, being published only in 1932. He followed this with The Poverty of Philosophy (1847), a response to the French anarcho - socialist Pierre - Joseph Proudhon's The Philosophy of Poverty and a critique of French socialist thought in general.

These books laid the foundation for Marx and Engels's most famous work, a political pamphlet that has since come to be commonly known as The Communist Manifesto. First published on 21 February 1848, it laid out the beliefs of the Communist League, a group who had come increasingly under the influence of Marx and Engels, who argued that the League must make their aims and intentions clear to the general public rather than hiding them as they had formerly been doing. The opening lines of the pamphlet set forth the principal basis of Marxism, that "The history of all hitherto existing society is the history of class struggles." It goes on to look at the antagonisms that Marx claimed were arising between the clashes of interest between the bourgeoisie (the wealthy middle class) and the proletariat (the industrial working class). Proceeding on from this, the Manifesto presents the argument for why the Communist League, as opposed to other socialist and liberal political parties and groups at the time, was truly acting in the interests of the proletariat to overthrow capitalist society and replace it with socialism.

Later that year, Europe experienced a series of protests, rebellions, and often violent upheavals, the Revolutions of 1848. In France, a revolution led to the overthrow of the monarchy and the establishment of the French Second Republic. Marx was supportive of such activity, and having recently received a substantial inheritance from his father of either 6000 or 5000 francs, allegedly used a third of it to arm Belgian workers who were planning revolutionary action. Although the veracity of these allegations is disputed, the Belgian Ministry of Justice accused him of it, subsequently arresting him, and he was forced to flee back to France, where, with a new republican government in power, he believed that he would be safe.

Temporarily settling down in Paris, Marx transferred the Communist League executive headquarters to the city and also set up a German Workers' Club with various German socialists living there. Hoping to see the revolution spread to Germany, in 1848 Marx moved back to Cologne where he began issuing a handbill entitled the Demands of the Communist Party in Germany, in which he argued for only four of the ten points of the Communist Manifesto, believing that in Germany at that time, the bourgeoisie must overthrow the feudal monarchy and aristocracy before the proletariat could overthrow the bourgeoisie. On 1 June, Marx started publication of the daily Neue Rheinische Zeitung ("New Rhenish Newspaper"), which he helped to finance through his recent inheritance from his father. Designed to put forward news from across Europe with his own Marxist interpretation of events, Marx remained one of its primary writers, accompanied by other fellow members of the Communist League who wrote for the paper, although despite their input it remained, according to Friedrich Engels, "a simple dictatorship by Marx", who dominated the choice of content.

Whilst editor of the paper, Marx and the other revolutionary socialists were regularly harassed by the police, and Marx was brought to trial on several occasions, facing various allegations including insulting the Chief Public Prosecutor, an alleged press misdemeanor and inciting armed rebellion through tax boycotting, although each time he was acquitted. Meanwhile, the democratic parliament in Prussia collapsed, and the king, Frederick William IV, introduced a new cabinet of his reactionary supporters, who implemented counter - revolutionary measures to expunge leftist and other revolutionary elements from the country. As a part of this, the Neue Rheinische Zeitung was soon suppressed and Marx was ordered to leave the country on 16 May. Marx returned to Paris, which was then under the grip of both a reactionary counter - revolution and a cholera epidemic, and was soon expelled by the city authorities who considered him a political threat. With his wife Jenny expecting their fourth child, and not able to move back to Germany or Belgium, in August 1849 he sought refuge in London.

Marx moved to London in May 1849 and would remain in the city for the rest of his life. It was here that he founded the new headquarters of the Communist League, and got heavily involved with the socialist German Workers' Educational Society, who held their meetings in Great Windmill Street, Soho, central London's entertainment district. Marx devoted himself to two activities: revolutionary organizing, and an attempt to understand political economy and capitalism. For the first few years he and his family lived in extreme poverty. His main source of income was his colleague, Engels, who derived much of his income from his family's business. Marx also briefly worked as correspondent for the New York Tribune in 1851.

From December 1851 to March 1852 Marx wrote The Eighteenth Brumaire of Louis Napoleon, a work on the French Revolution of 1848, in which he expanded upon his concepts of historical materialism, class struggle and the dictatorship of the proletariat, advancing the argument that victorious proletariat has to smash the bourgeois state.

The 1850s and 1860s also marks the line between what some scholars see as idealistic, Hegelian young Marx from the more scientifically - minded mature Marx writings of the later period. This distinction is usually associated with the structural Marxism school; not all scholars agree that it indeed exists.

In 1864 Marx became involved in the International Workingmen's Association (also known as First International). He became a leader of its General Council, to whose General Council he was elected at its inception in 1864. In that organization Marx was involved in the struggle against the anarchist wing centered around Mikhail Bakunin (1814 – 1876). Although Marx won this contest, the transfer of the seat of the General Council from London to New York in 1872, which Marx supported, led to the decline of the International. The most important political event during the existence of the International was the Paris Commune of 1871 when the citizens of Paris rebelled against their government and held the city for two months. On the bloody suppression of this rebellion, Marx wrote one of his most famous pamphlets, The Civil War in France, a defense of the Commune.

Given the repeated failures and frustrations of workers' revolutions and movements, Marx also sought to understand capitalism, and spent a great deal of time in the reading room of the British Museum studying and reflecting on the works of political economists and on economic data. By 1857 he had accumulated over 800 pages of notes and short essays on capital, landed property, wage labor, the state, foreign trade and the world market; this work did not appear in print until 1941, under the title Grundrisse. In 1859, Marx published Contribution to the Critique of Political Economy, his first serious economic work. In the early 1860s he worked on composing three large volumes, the Theories of Surplus Value, which discussed the theoreticians of political economy, particularly Adam Smith and David Ricardo. This work is often seen as the fourth book of Capital, and constitutes one of the first comprehensive treatises on the history of economic thought. In 1867 the first volume of Capital was published, a work which analyzed the capitalist process of production. Here, Marx elaborated his labor theory of value and his conception of surplus value and exploitation which he argued would ultimately lead to a falling rate of profit and the collapse of industrial capitalism. Volumes II and III remained mere manuscripts upon which Marx continued to work for the rest of his life and were published posthumously by Engels.

During the last decade of his life, Marx's health declined and he became incapable of the sustained effort that had characterized his previous work. He did manage to comment substantially on contemporary politics, particularly in Germany and Russia. His Critique of the Gotha Programme opposed the tendency of his followers Wilhelm Liebknecht and August Bebel to compromise with the state socialism of Ferdinand Lassalle in the interests of a united socialist party. This work is also notable for another famous Marx's quote: "From each according to his ability, to each according to his need."

In a letter to Vera Zasulich dated 8 March 1881, Marx even contemplated the possibility of Russia's bypassing the capitalist stage of development and building communism on the basis of the common ownership of land characteristic of the village mir. While admitting that Russia's rural "commune is the fulcrum of social regeneration in Russia", Marx also warned that in order for the mir to operate as a means for moving straight to the socialist stage without a preceding capitalist stage, it "would first be necessary to eliminate the deleterious influences which are assailing it (the rural commune) from all sides." Given the elimination of these pernicious influences, Marx allowed, that "normal conditions of spontaneous development" of the rural commune could exist. However, in the same letter to Vera Zasulich, Marx points out that "at the core of the capitalist system ... lies the complete separation of the producer from the means of production." In one of the drafts of this letter, Marx reveals his growing passion for anthropology, motivated by his belief that future communism would be a return on a higher level to the communism of our prehistoric past. He wrote that 'the historical trend of our age is the fatal crisis which capitalist production has undergone in the European and American countries where it has reached its highest peak, a crisis that will end in its destruction, in the return of modern society to a higher form of the most archaic type — collective production and appropriation'. He added that 'the vitality of primitive communities was incomparably greater than that of Semitic, Greek, Roman, etc. societies, and, a fortiori, that of modern capitalist societies'. Before he died, Marx asked Engels to write up these ideas, which were published in 1884 under the title The Origin of the Family, Private Property and the State.

Following the death of his wife Jenny in December 1881, Marx developed a catarrh that kept him in ill health for the last 15 months of his life. It eventually brought on the bronchitis and pleurisy that killed him in London on 14 March 1883. He died a stateless person; family and friends in London buried his body in Highgate Cemetery, London, on 17 March 1883. There were between nine to eleven mourners at his funeral.

Several of his closest friends spoke at his funeral, including Wilhelm Liebknecht and Friedrich Engels. Engels's speech included the passage:

Marx's daughter Eleanor and Charles Longuet and Paul Lafargue, Marx's two French socialist sons - in - law, were also in attendance. Liebknecht, a founder and leader of the German Social - Democratic Party, gave a speech in German, and Longuet, a prominent figure in the French working - class movement, made a short statement in French. Two telegrams from workers' parties in France and Spain were also read out. Together with Engels's speech, this constituted the entire programme of the funeral. Non - relatives attending the funeral included three communist associates of Marx: Friedrich Lessner, imprisoned for three years after the Cologne communist trial of 1852; G. Lochner, whom Engels described as "an old member of the Communist League" and Carl Schorlemmer, a professor of chemistry in Manchester, a member of the Royal Society, and a communist activist involved in the 1848 Baden revolution. Another attendee of the funeral was Ray Lankester, a British zoologist who would later become a prominent academic.

Upon his own death, Engels left Marx's two surviving daughters a "significant portion" of his $4.8 million estate.

Marx's tombstone bears the carved message: "WORKERS OF ALL LANDS UNITE", the final line of The Communist Manifesto, and from the 11th Thesis on Feuerbach (edited by Engels): "The philosophers have only interpreted the world in various ways — the point however is to change it". The Communist Party of Great Britain had the monumental tombstone built in 1954 with a portrait bust by Laurence Bradshaw; Marx's original tomb had had only humble adornment. In 1970 there was an unsuccessful attempt to destroy the monument using a homemade bomb.

The later Marxist historian Eric Hobsbawm remarked that "One cannot say Marx died a failure" because, although he had not achieved a large following of disciples in Britain, his writings had already begun to make an impact on the leftist movements in Germany and Russia. Within 25 years of his death, the continental European socialist parties that acknowledged Marx's influence on their politics were each gaining between 15 and 47% in those countries with representative democratic elections.

Marx's thought demonstrates influences from many thinkers, including but not limited to:

• Georg Wilhelm Friedrich Hegel's philosophy;
• The classical political economy (economics) of Adam Smith and David Ricardo;
• French socialist thought, in particular the thought of Jean - Jacques Rousseau, Henri de Saint - Simon and Charles Fourier;
• Earlier German philosophical materialism, particularly that of Ludwig Feuerbach;
• The working class analysis by Friedrich Engels.

Marx's view of history, which came to be called historical materialism (controversially adapted as the philosophy of dialectical materialism by Engels and Lenin) certainly shows the influence of Hegel's claim that one should view reality (and history) dialectically. However, Hegel had thought in idealist terms, putting ideas in the forefront, whereas Marx sought to rewrite dialectics in materialist terms, arguing for the primacy of matter over idea. Where Hegel saw the "spirit" as driving history, Marx saw this as an unnecessary mystification, obscuring the reality of humanity and its physical actions shaping the world. He wrote that Hegelianism stood the movement of reality on its head, and that one needed to set it upon its feet.

Though inspired by French socialist and sociological thought, Marx criticized utopian socialists, arguing that their favored small scale socialistic communities would be bound to marginalization and poverty, and that only a large scale change in the economic system can bring about real change.

The other important contribution to Marx's revision of Hegelianism came from Engels's book, The Condition of the Working Class in England in 1844, which led Marx to conceive of the historical dialectic in terms of class conflict and to see the modern working class as the most progressive force for revolution.

Marx believed that he could study history and society scientifically and discern tendencies of history and the resulting outcome of social conflicts. Some followers of Marx concluded, therefore, that a communist revolution would inevitably occur. However, Marx famously asserted in the eleventh of his Theses on Feuerbach that "philosophers have only interpreted the world, in various ways; the point however is to change it", and he clearly dedicated himself to trying to alter the world.

Marx polemic with other thinkers often occurred through critique, and thus he has been called "the first great user of critical method in social sciences." He criticized speculative philosophy, equating metaphysics with ideology. By adopting this approach, Marx attempted to separate key findings from ideological biases. This set him apart from many contemporary philosophers.

Fundamentally, Marx assumed that human history involves transforming human nature, which encompasses both human beings and material objects. Humans recognize that they possess both actual and potential selves. For both Marx and Hegel, self - development begins with an experience of internal alienation stemming from this recognition, followed by a realization that the actual self, as a subjective agent, renders its potential counterpart an object to be apprehended. Marx further argues that, by molding nature in desired ways, the subject takes the object as its own, and thus permits the individual to be actualized as fully human. For Marx, then,human nature — Gattungswesen, or species - being — exists as a function of human labor. Fundamental to Marx's idea of meaningful labor is the proposition that, in order for a subject to come to terms with its alienated object, it must first exert influence upon literal, material objects in the subject's world. Marx acknowledges that Hegel "grasps the nature of work and comprehends objective man, authentic because actual, as the result of his own work", but characterizes Hegelian self - development as unduly "spiritual" and abstract. Marx thus departs from Hegel by insisting that "the fact that man is a corporeal, actual, sentient, objective being with natural capacities means that he has actual, sensuous objects for his nature as objects of his life - expression, or that he can only express his life in actual sensuous objects." Consequently, Marx revises Hegelian "work" into material "labor", and in the context of human capacity to transform nature the term "labor power".

The history of all hitherto existing society is the history of class struggles.

— Karl Marx, The Communist Manifesto

Marx had a special concern with how people relate to that most fundamental resource of all, their own labor power. He wrote extensively about this in terms of the problem of alienation. As with the dialectic, Marx began with a Hegelian notion of alienation but developed a more materialist conception. Capitalism mediates social relationships of production (such as among workers or between workers and capitalists) through commodities, including labor, that are bought and sold on the market. For Marx, the possibility that one may give up ownership of one's own labor — one's capacity to transform the world — is tantamount to being alienated from one's own nature; it is a spiritual loss. Marx described this loss as commodity fetishism, in which the things that people produce, commodities, appear to have a life and movement of their own to which humans and their behavior merely adapt.

Commodity fetishism provides an example of what Engels called "false consciousness", which relates closely to the understanding of ideology. By "ideology", Marx and Engels meant ideas that reflect the interests of a particular class at a particular time in history, but which contemporaries see as universal and eternal. Marx and Engels's point was not only that such beliefs are at best half - truths; they serve an important political function. Put another way, the control that one class exercises over the means of production includes not only the production of food or manufactured goods; it includes the production of ideas as well (this provides one possible explanation for why members of a subordinate class may hold ideas contrary to their own interests). An example of this sort of analysis is Marx's understanding of religion, summed up in a passage from the preface to his 1843 Contribution to the Critique of Hegel's Philosophy of Right:

Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people. The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions.

—Karl Marx, Contribution to the Critique of Hegel's Philosophy of Right

Whereas his Gymnasium senior thesis argued that religion had as its primary social aim the promotion of solidarity, here Marx sees the social function of religion in terms of highlighting / preserving political and economic status quo and inequality.

Marx's thoughts on labor were related to the primacy he gave to the economic relation in determining the society's past, present and future (economic determinism). Accumulation of capital shapes the social system. Social change, for Marx, was about conflict between opposing interests, driven, in the background, by economic forces. This became the inspiration for the body of works known as the conflict theory. In his evolutionary model of history, he argued that human history began with free, productive and creative work that was over time coerced and dehumanized, a trend most apparent under capitalism. Marx noted that this was not an intentional process; rather, no individual or even no state can go against the forces of economy.

The organization of society depends on means of production. Literally those things, like land, natural resources, and technology, necessary for the production of material goods and the relations of production, in other words, the social relationships people enter into as they acquire and use the means of production. Together these compose the mode of production, and Marx distinguished historical eras in terms of distinct modes of production. Marx differentiated between base and superstructure, with the base (or substructure) referring to the economic system, and superstructure, to the cultural and political system. Marx regarded this mismatch between (economic) base and (social) superstructure as a major source of social disruption and conflict.

Despite Marx's stress on critique of capitalism and discussion of the new communist society that should replace it, his explicit critique of capitalism is guarded, as he saw it as an improved society compared to the past ones (slavery and feudal). Marx also never clearly discusses issues of morality and justice, although scholars agree that his work contained implicit discussion of those concepts.

Marx's view of capitalism was two sided. On one hand, Marx, in the 19th century's deepest critique of the dehumanizing aspects of this system, noted that defining features of capitalism include alienation, exploitation and recurring, cyclical depressions leading to mass unemployment; on the other hand capitalism is also characterized by "revolutionizing, industrializing and universalizing qualities of development, growth and progressivity" (by which Marx meant industrialization, urbanization, technological progress, increased productivity and growth, rationality and scientific revolution), that are responsible for progress. Marx considered the capitalist class to be one of the most revolutionary in history, because it constantly improved the means of production, more so than any other class in history, and was responsible for the overthrow of feudalism and its transition to capitalism. Capitalism can stimulate considerable growth because the capitalist can, and has an incentive to, reinvest profits in new technologies and capital equipment.

According to Marx capitalists take advantage of the difference between the labor market and the market for whatever commodity the capitalist can produce. Marx observed that in practically every successful industry input unit costs are lower than output unit prices. Marx called the difference "surplus value" and argued that this surplus value had its source in surplus labor, the difference between what it costs to keep workers alive and what they can produce. Marx's dual view of capitalism can be seen in his description of the capitalists: he refers to them as to vampires sucking worker's blood, but at the same time, he notes that drawing profit is "by no means an injustice" and that capitalists simply cannot go against the system. The true problem lies with the "cancerous cell" of capital, understood not as property or equipment, but the relations between workers and owners – the economic system in general.

At the same time, Marx stressed that capitalism was unstable, and prone to periodic crises. He suggested that over time, capitalists would invest more and more in new technologies, and less and less in labor. Since Marx believed that surplus value appropriated from labor is the source of profits, he concluded that the rate of profit would fall even as the economy grew. Marx believed that increasingly severe crises would punctuate this cycle of growth, collapse, and more growth. Moreover, he believed that in the long term this process would necessarily enrich and empower the capitalist class and impoverish the proletariat. In section one of The Communist Manifesto Marx describes feudalism, capitalism, and the role internal social contradictions play in the historical process:

We see then: the means of production and of exchange, on whose foundation the bourgeoisie built itself up, were generated in feudal society. At a certain stage in the development of these means of production and of exchange, the conditions under which feudal society produced and exchanged ... the feudal relations of property became no longer compatible with the already developed productive forces; they became so many fetters. They had to be burst asunder; they were burst asunder. Into their place stepped free competition, accompanied by a social and political constitution adapted in it, and the economic and political sway of the bourgeois class. A similar movement is going on before our own eyes ... The productive forces at the disposal of society no longer tend to further the development of the conditions of bourgeois property; on the contrary, they have become too powerful for these conditions, by which they are fettered, and so soon as they overcome these fetters, they bring order into the whole of bourgeois society, endanger the existence of bourgeois property.

—Karl Marx, The Communist Manifesto

Marx believed that those structural contradictions within capitalism necessitate its end, giving way to socialism, or a post - capitalistic, communist society:

The development of Modern Industry, therefore, cuts from under its feet the very foundation on which the bourgeoisie produces and appropriates products. What the bourgeoisie, therefore, produces, above all, are its own grave - diggers. Its fall and the victory of the proletariat are equally inevitable."

—Karl Marx and Frederic Engels, The Communist Manifesto

Thanks to various processes overseen by capitalism, such as urbanization, the working class, the proletariat, should grow in numbers and develop a class consciousness, in time realizing that they have to change the system. Marx believed that if the proletariat were to seize the means of production, they would encourage social relations that would benefit everyone equally, abolishing exploiting class, and introduce a system of production less vulnerable to cyclical crises. Marx argued that capitalism will end through the organized actions of an international working class:

Communism is for us not a state of affairs which is to be established, an ideal to which reality will have to adjust itself. We call communism the real movement which abolishes the present state of things. The conditions of this movement result from the premises now in existence."

—Karl Marx, The German Ideology

In this new society the self - alienation would end, and humans would be free to act without being bound by the labor market. It would be a democratic society, enfranchising the entire population. In such a utopian world there would also be little if any need for a state, which goal was to enforce the alienation. He theorized that between capitalism and the establishment of a socialist / communist system, a dictatorship of the proletariat — a period where the working class holds political power and forcibly socializes the means of production — would exist. As he wrote in his "Critique of the Gotha Program", "between capitalist and communist society there lies the period of the revolutionary transformation of the one into the other. Corresponding to this is also a political transition period in which the state can be nothing but the revolutionary dictatorship of the proletariat." While he allowed for the possibility of peaceful transition in some countries with strong democratic institutional structures (such as Britain, the US and the Netherlands), he suggested that in other countries with strong centralized state - oriented traditions, like France and Germany, the "lever of our revolution must be force."

Marx married Jenny von Westphalen in 1843. Together had seven children, but partly due to the poor living conditions they were forced to live in whilst in London, only three survived to adulthood. The children were: Jenny Caroline (m. Longuet; 1844 – 83); Jenny Laura (m. Lafargue; 1845 – 1911); Edgar (1847 – 1855); Henry Edward Guy ("Guido"; 1849 – 1850); Jenny Eveline Frances ("Franziska"; 1851 – 52); Jenny Julia Eleanor (1855 – 98) and one more who died before being named (July 1857). There are allegations that Marx also fathered a son, Freddy, out of wedlock by his housekeeper, Helene Demuth.

Marx frequently used pseudonyms, often when renting a house or flat, apparently to make it harder for the authorities to track him down. While in Paris, he used that of 'Monsieur Ramboz', whilst in London he signed off his letters as 'A. Williams'. His friends referred to him as 'Moor', due to his dark complexion and black curly hair, something which they believed made him resemble the historical Moors of North Africa, whilst he encouraged his children to call him 'Old Nick' and 'Charley'. He also bestowed nicknames and pseudonyms on his friends and family as well, referring to Friedrich Engels as 'General', his housekeeper Helene as 'Lenchen' or 'Nym', while one of his daughters, Jennychen, was referred to as 'Qui Qui, Emperor of China' and another, Laura, was known as 'Kakadou' or 'the Hottentot'.

“	A knowledge of the writings of Marx and Engels is virtually indispensable to an educated person in our time.... For classical Marxism... has profoundly affected ideas about history, society, economics, culture and politics; indeed, about the nature of social inquire itself... Not to be well grounded in the writings of Marx and Engels is to be insufficiently attuned to modern thought, and self - excluded to a degree from the continuing debate by which most contemporary societies live insofar as their members are free and able to discuss the vital issues.	”
	— Robert C. Tucker, The Marx - Engels Reader, 1978

Marx has widely been thought of as one of the most influential thinkers in history, who has had a significant influence on both world politics and intellectual thought. Marx's biographer Francis Wheen considered the "history of the twentieth century" to be "Marx's legacy", whilst Australian philosopher Peter Singer believed that Marx's impact could be compared with that of the founders of the two major world religions, Jesus Christ and Muhammad. Singer noted that "Marx's ideas brought about modern sociology, transformed the study of history, and profoundly affected philosophy, literature and the arts." Stokes said that Marx's ideas led to him becoming "the darling of both European and American intellectuals up until the 1960s", and have influenced a wide variety of disciplines, including archaeology, anthropology, media studies, political science, theater, history, sociological theory, cultural studies, education, economics, geography, literary criticism, aesthetics, critical psychology, and philosophy.

In July 2005, 27.9% of listeners in a BBC Radio 4 series In Our Time poll selected Marx as their favorite thinker.

The reasons for Marx's widespread influence revolve around his ethical message; a "morally empowering language of critique" against the dominant capitalist society. No other body of work was so relevant to the modern times, and at the same time, so outspoken about the need for change. In the political realm, Marx's ideas led to the establishment of governments using Marxist thought to replace capitalism with communism or socialism (or augment it with market socialism) across much of the world, whilst his intellectual thought has heavily influenced the academic study of the humanities and the arts.

“	The merit of Marx is that he suddenly produces a qualitative change in the history of social thought. He interprets history, understands its dynamic, predicts the future, but in addition to predicting it, he expresses a revolutionary concept: the world must not only be interpreted, it must be transformed.	”
	— Che Guevara, Marxist revolutionary

Followers of Marx have drawn on his work to propose grand, cohesive theoretical outlooks dubbed "Marxism". This body of works has had significant influence on the both political and scientific scenes. Nevertheless, Marxists have frequently debated amongst themselves over how to interpret Marx's writings and how to apply his concepts to their contemporary events and conditions. The legacy of Marx's thought has become bitterly contested between numerous tendencies which each see themselves as Marx's most accurate interpreters, including (but not limited to) Leninism, Stalinism, Trotskyism, Maoism, Luxemburgism, and libertarian Marxism. In academic Marxism, various currents have developed as well, often under influence of other views, resulting in structuralist Marxism, historical Marxism, phenomenological Marxism, Analytical Marxism and Hegelian Marxism.

Moreover, one should distinguish between "Marxism" and "what Marx believed"; for example, shortly before he died in 1883, Marx wrote a letter to the French workers' leader Jules Guesde, and to his own son - in - law Paul Lafargue, accusing them of "revolutionary phrase - mongering" and of lack of faith in the working class. After the French party split into a reformist and revolutionary party, some accused Guesde (leader of the latter) of taking orders from Marx; Marx remarked to Lafargue, "if that is Marxism, then I am not a Marxist" (in a letter to Engels, Marx later accused Guesde of being a "Bakuninist").

Marx is typically cited, along with Émile Durkheim and Max Weber, as one of the three principal architects of modern social science. In contrast to philosophers, Marx offered theories that could often be tested with the scientific method. Both Marx and Auguste Comte set out to develop scientifically justified ideologies in the wake of European secularization and new developments in the philosophies of history and science. Whilst Marx, working in the Hegelian tradition, rejected Comtean sociological positivism, in attempting to develop a science of society he nevertheless came to be recognized as a founder of sociology as the word gained wider meaning. In modern sociological theory, Marxist sociology is recognized as one of the main classical perspectives. For Isaiah Berlin, Marx may be regarded as the "true father" of modern sociology, "in so far as anyone can claim the title."