On materialism:

"The first historical act is. . . the production of material life itself.  This is indeed a historical act, a fundamental condition of all of history" (1964, p. 60)

"By thus acting on the external world and changing it, he at the same time changes his own nature (Capital, vol. 1, p. 174).

"Legal relations as well as form of state are to be grasped neither from themselves nor from the so-called general development of the human mind, but rather have their roots in the material conditions of life, the sum total of which Hegel . . . combines under the name of 'civil society.' . . . The anatomy of civil society is to be sought in political economy"  (1962, vol. 1, p. 362). 

"The political, legal, philosophical, literary, and artistic development rests on the economic.  But they all react upon one another and upon the economic base.  It is not the case that the economic situation is the sole active cause and that everything else is merely a passive effect.  There is, rather, a reciprocity within a field of economic necessity which in the last instance always asserts itself" (1962, vol. 2, p. 304). 

"In the social production which men carry on as they enter into definite relations that are indispensable and independent of their will; these relations of production correspond to a definite stage of development of their material powers of production.  The totality of these relations of production constitutes the economic structure of society--the real foundation, on which legal and political superstructures arise and to which definite forms of social consciousness correspond.  The mode of production of material life determines the general character of the social, political and spiritual processes of life.  It is not the consciousness of men that determines their being, but, on the contrary, their social being determines their consciousness"  (1964, p. 51). 

"According to the materialist conception of history, the ultimately determinant element in history is the production and reproduction of real life. . . . Hence if somebody twists this into saying that the economic element is the only determining one, he transforms that proposition into a meaningless, abstract and senseless phrase.  The economic situation is the basis, but the various elements of the superstructure. . . also exercise their influence upon the course of the historical struggle and in many cases preponderate in determining their form" (1962, II, p. 488). 

"M. Proudhon the economist understands very well that men make cloth, linen or silk materials in definite relations of production.  But what he has not understood is that these definite social relations are just as much produced by men as linen, flax, etc.  Social relations are closely bound up with productive forces.  In acquiring new productive forces men change their mode of production; and in changing their mode of production, in changing the way of earning their living, they change all their social relations. The hand-mill gives you society with the feudal lord; the steam-mill, society with the industrial capitalist" (The Poverty of Philosophy, p. 92).

On elites: 

"The ideas of the ruling class are, in every age, the ruling ideas:  i.e., the class which is the dominant material force in society is at the same time its dominant intellectual force.  The class which has the means of production at its disposal, has control at the same time over the means of mental production"  (1964, p. 78). 

[We go astray] "if . . . we detach the ideas of the ruling class from the ruling class itself and attribute to them an independent existence, if we confine ourselves to saying that in a particular age these or those ideas were dominant, without paying attention to the conditions of production and the producers of these ideas, and if we thus ignore the individuals and the world conditions which are the source of these ideas"  (1964, p.p. 79-80).

On social evolution: 

"The economic structure of capitalist society has grown out of the economic structure of feudal society.  The dissolution of the latter sets free the elements of the former"  (1964, p. 133). 

"No social order ever disappears before all the productive forces for which there is room in it have been developed; and new higher relations of production never appear before the material conditions of their existence have matured in the womb of the old society"  (1964, p. 52). 

"The philosophers have only interpreted the world in various ways; the point however is to change it." (1845). 

On class:

"The history of all hitherto existing society is the history of class struggles"  (1962, vol 1, p. 34). 

"The separate individuals form a class only in so far as they have to carry on a common battle against another class; otherwise they are on hostile terms with each other as competitors"  (1930, pp. 48-49). 

[The major modern classes are] "the owners merely of labor-power, owners of capital, and landowners, whose respective sources of income are wages, profit and ground rent"  (1964, p. 178). 

"The State is the form in which the individuals of a ruling class assert their common interests"  (1964, p. 78). 

"Workers of the world, unite! You have nothing to lose but your chains." (1848).

“The greater the social wealth, the functioning capital, the extent and energy of its growth, and therefore also the greater the absolute mass of the proletariat and the productivity of its labor, the greater is the industrial reserve army….But the greater this reserve army in proportion to the active labour army, the greater is the mass of a consolidated surplus population, whose misery is in inverse ration to the amount of torture it has to undergo in the form of labour. The more extensive, finally, the pauperized sections of the working class and the industrial reserve army, the greater is official pauperism. This is the absolute general law of capitalist accumulation. Like all other laws, it is modified in its working by many circumstances, the analysis of which does not concern us here” (Capital, vol. 1, p. 798).

On alienation and religion: 

"Objectification is the practice of alienation.  Just as man, so long as he is engrossed in religion, can only objectify his essence by an alien and fantastic being; so under the sway of egoistic need, he can only affirm himself and produce objects in practice by subordinating his products and his own activity to the domination of an alien entity, and by attributing to them the significance of an alien entity, namely money"  (1964b, p. 39). 

"The commodity form and the value relation between the products of labor which stamps them as commodities, have absolutely no connection with their physical properties and with the material relations arising there from.  It is simply a definite relationship between men, that assumes in their eyes the fantastic form of a relations between things.  To find an analogy, we must have recourse to the nebulous regions of the religious world.  In that world the productions of the human brain appear as independent beings endowed with life, and entering into relation both with one another and with the human race.  So it is in the world of commodities, with the products of men's hands.  This I call the fetishism which attaches itself tot he products of labor, as soon as they are produced as commodities"  (1964, pp. 175-176). 

"Religious distress is at the same time the expression of real distress and the protest against real distress. Religion is the sigh of the oppressed creature, the heart of a heartless world, just as it is the spirit of an unspiritual situation. It is the opium of the people" (1959, p. 263). 

On the sanctity of work: 

"We are not now dealing with those primitive instinctive forms of labour that remind us of the mere animal.  We pre-suppose labour in a from that stamps it as exclusively human.  A spider conducts operations that resemble those of a weaver, and a bee puts to shame many an architect in the construction of her cells.  But what distinguishes the worst architect from the best of bees is this, that the architect raises his structure in imagination before he erects it in reality.  At the end of every labour-process, we get a result that already existed in the imagination of the labourer at its commencement.  He not only effects a change of form in the material on which he works, but he also realizes a purpose of his own that gives the law to his modus operandi, and to which he must subordinate his will" (Capital, vol. I, p. 174).

"The bourgeoisie, wherever it has got the upper hand, has put an end to all feudal, patriarchal, idyllic relations. It has pitilessly torn asunder the motley feudal ties that bound man to his "natural superiors", and has left no other nexus between people than naked self-interest, than callous "cash payment".  It has drowned out the most heavenly ecstacies of religious fervor, of chivalrous enthusiasm, of philistine sentimentalism, in the icy water of egotistical calculation. It has resolved personal worth into 
exchange value, and in place of the numberless indefeasible chartered freedoms, has set up that single, unconscionable freedom -- Free Trade. In one word, for exploitation, veiled by religious and political illusions, it has substituted naked, shameless, direct, brutal exploitation (1846/1954) 

"The bourgeoisie has stripped of its halo every occupation hitherto honored and looked up to with reverent awe. It has converted the physician, the lawyer, the priest, the poet, the man of science, into its paid wage laborers (1848/1954).

“Even the need for fresh air ceases to be a need for the worker. Man reverts once more to living in a cave, but the cave is now polluted by the mephitic and pestilential breath of civilization. Moreover, the worker has no more than a precarious right to live in it, for it is for him an alien power that can be daily withdrawn and from which, should he fail to pay, he can be evicted at any time. He actually has to pay for this mortuary. A dwelling in the light, which Prometheus describes in Aeschylus as one of the great gifts through which he transformed savages into men, ceases to exist for the worker. Light, air, etc.—the simple animal cleanliness—ceases to be a need for man. Dirt—this pollution and putrefacation of man, the sewage (this word is to be understood in its literal sense) of civilization—becomes an element of life for him. Universal unnatural neglect, putrefied nature, becomes an element of life for him” (Marx’s Early Writing, 359-360).

On science and technology:

The machine proper is therefore a mechanism that, after being set in motion, performs with its tools the same operations that were formerly done by the workman with similar tools.  Whether the motive power is derived from man, or from some other machine, makes no difference in this respect.  From the moment that the tool proper is taken from man, and fitted into a mechanism, a machine takes the place of a mere implement.  The difference strikes one at once, even in those cases where man himself continues to be the prime mover" (Capital, vol. I, pp. 353-354).

"Every kind of capitalist production, in so far as it is not only a labour-process, but also a process of creating surplus-value, has this in common, that it is not the workman that employs the instruments of labour, but the instruments of labour that employ the workman.  But it is only in the factory system that this inversion for the first time acquires technical and palpable reality.  By means of its conversion into an automaton, the instrument of labour confront the labourer, during the labour-process, in the shape of capital, of dead labour, that dominates and pumps dry, living labour-power.  The separation of the intellectual powers of production from the manual labour, and the conversion of those powers into the might of capital over labour, is, as we have already shown, finally completed by modern industry erected on the foundation of machinery. the special skill of each individual insignificant factory operative vanishes as an infinitesimal quantity before the science, the gigantic physical forces, and the mass of labour that are embodied in the factory mechanism and, together with that mechanism, constitute the power of the 'master'" (Capital, vol. I, pp. 393-394)

"Modern Industry rent the veil that concealed from men their own social process of production, and that turned the various, spontaneously divided branches of production into so many riddles, not only to outsiders, but even to the. initiated. The principle which it pursued, of resolving each process into its constituent movements, without any regard to their possible execution by the hand of man, created the new modern science of technology. The varied, apparently unconnected, and petrified forms of the industrial processes now resolved themselves into so many conscious and systematic applications of natural science to the attainment of given useful effects" (Capital, vol. I, pp. 456-457).

On alienation: 

"Money is the alienated essence of man's work and existence; the essence dominates him and he worships it" (1964b, p. 37). 

"The state is the intermediary between men and human liberty.  Just as Christ is the intermediary to whom man attributes all his own divinity and all his religious bonds, so the state is the intermediary to which man confides all his non divinity and human freedom"  (1964b, p. II). 

"Religious alienation as such occurs only in the sphere of consciousness, in the inner life of man, but economic alienation is that of real life. . . . It therefore affects both aspects"  (1964b, p. 156). 

"The object produced by labor, its product, now stands opposed to it as an alien being, as a power independent of the producer. . . . The more the worker expends himself in work the more powerful becomes the world of objects which he creates in face of himself, the poorer he becomes in his inner life, and the less he belongs to himself"  (1964b, p. 122). 

"However, alienation appears not merely in the result but also in the process of production, within productive activity itself. . . . If the product of labor is alienation, production itself must be active alienation. . . . The alienation of the object of labor merely summarizes the alienation in the work activity itself"  (1964b, p. 124). 

"Work is external to the worker. . . . It is not part of his nature; consequently he does not fulfill himself in his work but denies himself. . . . The worker therefore feels himself at home only during his leisure time, whereas at work he feels homeless"  (1964b, pp. 124-125). 

"This is the relationship of the worker to his own activity as something alien, not belonging to him, activity as suffering (passivity), strength as powerlessness, creation as emasculation, the personal physical and mental energy of the worker, his personal life. . . . as an activity which is directed against himself, independent of him and not belonging to him"  (1964b, p. 125). 

"What is true of man's relationship to his work, to the product of his work and to himself, is also true of his relationship to other men. . . . Each man is alienated from others . . .each of the others is likewise alienated from human life" (1964b, p. 129). 

"The bourgeoisie has torn away from the family its sentimental veil, and has reduced the family relation into a mere money relation" (1848/1954). 

On Capitalism:

“The discovery of gold and silver in America, the extirpation, enslavement and entombment in mines of the indigenous population of that continent, the beginnings of the conquest and plunder of India, and the conversion of Africa into a preserve for the commercial hunting of blackskins, are all things which characterize the dawn of the era of capitalist production. These idyllic proceedings are the chief moments of primitive accumulation. On their heels treads the commercial war of the European nations, with the globe for a theatre” (Capital, vol. 1, p. 915)

“Accumulate, accumulate! That is Moses and the Prophets!” (Capital, vol. 1, chapter 24, section 3).

But if a surplus labouring population is a necessary product of accumulation or of the development of wealth on a capitalist basis, this surplus-population becomes, conversely, the lever of capitalistic accumulation, nay, a condition of existence of the capitalist mode of production.  It forms a disposable industrial reserve army, that belongs to capital quite as absolutely as if the latter had bred it at its own cost.  Independently of the limits of the actual increase of population, it creates, for the changing needs of the self-expansion of capital, a mass of human material always ready for exploitation (Capital, vol. I, pp. 592).

With accumulation, and the development of the productiveness of labour that accompanies it, the power of sudden expansion of capital grows also....The mass of social wealth, overflowing with the advance of accumulation, and transformable into additional capital, thrusts itself frantically into old branches of production, whose market suddenly expands, or into newly formed branches....In all such cases, there must be the possibility of throwing great masses of men suddenly on the decisive points without injury to the scale of production in other spheres....This increase is effected by the simple process that constantly 'sets free' a part of the labourers; by methods which lessen the number of labourers employed to the increased production.  The whole form of the movement of modern industry depends, therefore, upon the constant transformation of a part of the labouring population into unemployed or half-employed hands" (Capital, vol. I, pp. 592-593).

"The more extensive, finally, the lazarus-layers of the working class and the industrial reserve army, the greater is official pauperism" (Capital, vol. 1, p. 611)

"A service is nothing more than the useful effect of a use-value, be it of a commodity, or be it of labour" (Capital, vol. 1, p. 187).

“The bourgeoisie, during its rule of scarce one hundred years, has created more massive and more colossal productive forces than have all preceding generations together. Subjection of Nature’s forces to man, machinery, application of chemistry to industry and agriculture, steam-navigation, railways, electric telegraphs, clearing of whole continents for cultivation, canalization of rivers, while population conjured out of the ground. What earlier century had even a presentiment that such productive forces slumbered in the lap of social labor” (Communist Manifesto, p. 10).

On Capitalist Agriculture:

“Large landed property reduces the agricultural population to an ever decreasing minimum and confronts it with an ever growing industrial population crammed together in large towns; in this way it produces conditions that provoke an irreparable rift in the interdependent process of social metabolism, a metabolism prescribed by the natural laws of life itself. The result of this is a squandering of the vitality of the soil, which is carried by trade far beyond the bounds of a single country” (Marx and Engels, Collected Works, vol. 42, p. 227).

“Large-scale industry and industrially pursued large-scale agriculture have the same effect. If they are originally distinguished by the fact that the former lays waste and ruins labour-power and thus the natural power of man, whereas the latter does the same to the natural power of the soil, they link up in the later course of development, since the industrial system applied to agriculture also enervates the workers there, while industry and trade for their part provide agriculture with the means of exhausting the soil” (Capital, vol. 1, p. 638).

“Capitalist production collects the population together in great centres, and causes the urban population to achieve an ever-growing preponderance. This has two results. On the one hand, it disturbs the metabolic interaction between man and the earth, i.e. it prevents the return to the soil of its constituent elements consumed by man in the form of food and clothing; hence it hinders the operation of the eternal condition for the lasting fertility of the soil….But by destroying the circumstances surrounding that metabolism…it compels its systematic restoration as a regulative law of social production, and in a form adequate to the full development of the human race….[A]ll progress in capitalist agriculture is a progress in the art, not only of robbing the worker but of robbing the soil; all progress in increasing the fertility of the soil for a given time is a progress toward ruining the more long-lasting sources of that fertility….Capitalist production, therefore, only develops the technique and the degree of combination of the social process of production by simultaneously undermining the sources of all wealth—the soil and the worker (Capital, vol. 1. pp. 637-638) (Foster, 2000, pp. 155-156).

“Freedom in this sphere [the realm of natural necessity] can consist only in this, that socialized man, the associated producers, govern the human metabolism with nature in a rational way, bringing it under their own collective control instead of being dominated by it as a blind power; accomplishing it with the least expenditure of energy and in conditions most worthy and appropriate for their human nature” (Capital, vol. 3, p. 959).

“The way that the cultivation of particular crops depends on fluctuations in market prices and the constant changes in cultivation with these price fluctuations—the entire spirit of capitalist production, which is oriented towards the most immediate monetary profits—stands in contradiction to agriculture, which has to concern itself with the whole gamut of permanent conditions of life required by the chain of human generations” (Capital, vol. 3, p. 754) (Foster, 2000, p. 164).

“From the standpoint of a higher socio-economic formation, the private property of particular individuals in the earth will appear just as absurd as the private property of one man in other men. Even an entire society, a nation, or all simultaneously existing societies taken together, are not the owners of the earth. They are simply its possessor, its beneficiaries, and have to bequeath it in an improved state to succeeding generations as boni patres familias” [good heads of household] (Capital, vol. 3, p. 911).

“The moral of the tale is that the capitalist system runs counter to a rational agriculture, or that a rational agriculture is incompatible with the capitalist system (even if the latter promotes technical development in agriculture) and needs either small farmers working for themselves or the control of associated producers” (Capital, vol. 3, p. 216).

On Nature:

“The universality of man manifests itself in practice in the universality which makes the whole of nature as his inorganic body, (1) as a direct means of life and (2) as the matter, the object and tool of his activity. Nature is man’s inorganic body, that is to say, nature is so far as it is not the human body. Man lives from nature, i.e. nature is his body, and he must maintain a continuing dialogue with it if he is not to die. To say that man’s physical and mental life is linked to nature simply means that nature is linked to itself, for man is a part of nature” (Early Writings, p. 328).

“For the first time nature becomes purely an object for humankind, purely a matter of utility; ceases to be recognized as a power for itself; and the theoretical discovery of its autonomous laws appears merely as a ruse so as to subject it under human needs, whether as an object of consumption or as a means of production” (Grundrisse, New York: Vintage, pp. 409-410).

“It is not the unity of living and active humanity with the natural, inorganic conditions of their metabolic exchange with nature, and hence their appropriation of nature, which requires explanation or is the result of a historic process, but rather the separation between these inorganic conditions of human existence and this active existence, a separation which is completely posited only in the relation of wage labor and capital” (Grundrisse, New York: Vintage, p. 489).

“Freedom in this sphere [the realm of natural necessity] can consist only in this, that socialized man, the associated producers, govern the human metabolism with nature in a rational way, bring it under their collective control instead of being dominated by it as a blind power, accomplishing it with the least expenditure of energy and in conditions most worthy and appropriate for their human nature” (Capital, vol. 1, p. 638).

[The] "conscious and rational treatment of the land as permanent communal property [is] the inalienable condition for the existence and reproduction of the chain of human generations" (Capital, vol. 3, pp. 948-949).

"From the standpoint of a higher socio-economic formation, the private property of particular individuals in the earth will appear just as absurd as the private property of one man in other men. Even an entire society, a nation, or all simultaneously existing societies taken together, are not owners of the earth, they are simply its possessors, its beneficiaries, and have to bequeath it in an improved state to succeeding generations, as boni patres familias [good heads of household] (Capital, vol. 3, p. 911).

“The first premise of all human existence and, therefore, of all history…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. And indeed this is an historical act, a fundamental condition of all history, which today, as thousands of years ago, must daily and hourly be fulfilled merely in order to sustain human life…the production of life, both of one’s own in labour and of fresh life in procreation…appears as a twofold relation: on the one hand as a natural, on the other hand as a social relation” (Marx and Engels Collected Works, vol. 5, pp. 41-43).

“Labour is, first of all, a process between man and nature, a process by which man, through his own actions, mediates, regulates and controls the metabolism between himself and nature. He confronts the material of nature as a force of nature. He sets in motion the natural forces which belong to his own body, his arms, legs, head and hands, in order to appropriate the materials of nature in a form adapted to his own needs. Through this movement he acts upon external nature and changes it, and in this way he simultaneously changes his own nature” (Capital, vol. 1. p. 283).

“It [the labor process] is the universal condition for the metabolic interaction [Stoffwechsel] between man and nature, the everlasting nature-imposed condition of human existence” (Capital, vol. 1. p. 290).

On Spartacus:

[Spartacus was] "the most splendid fellow that all ancient history has to show; great general, noble character, real representative of the ancient proletariat."

From Engles' Eulogy (1883)

Just as Darwin discovered the law of evolution in organic nature, so Marx discovered the law of evolution in human history; he discovered the simple fact...that mankind must first of all eat and drink, have shelter and clothing, before it can pursue politics, science, religion, art, etc., and that therefore the production of the immediate material means of subsistence and consequently the degree of economic development attained by a given people or during a given epoch, form the foundation upon which the state institutions, the legal conceptions, the art and even the religious ideas of the people concerned have been evolved, and in the light of which these things must therefore be explained.

Sources: 

Marx, Karl.  1848/1954.  The Communist Manifesto.  Henry Reginery Company: Chicago. 

Marx, Karl.  1964.  Selected Writings in Sociology and Social Philosophy.  (translated by T.B. Bottomore).  London:  McGraw-Hill. 

Marx, Karl and Friedrich Engels,  1962.  Selected Works, 2 vols.  Moscow:  Foreign Language Publishing House. 

Marx, Karl and Friedrich Engels, 1930.  The German Ideology.  New York:  International Publishers. 

Marx, Karl.  1964b. Early Writings.  translated and edited by T. B. Bottomore.  New york: McGraw-Hill. 

Marx, Karl. 1959. Toward the Critique of Hegel's Philosophy of right, in Marx and Engels, Basic Writings, Lewis S. Feuer (ed). New York: Doubleday & Co., Anchor Books. 

Marx, Karl. 1845. Eleven Theses on Feurback.

Marx, Karl, 1973, Grundrisse. New York: Vintage.