Marx, Weber, and Classical Slavery*
From its beginning, modern discussion of ancient slavery has been inextricably linked with the debate on the usefulness and legitimacy of slavery in the New World. Therefore, in order properly to understand the views of Karl Marx (1818-1883) and Max Weber (1864-1920) on slavery in the ancient world, we have to look back to the abolitionist case of the 18th and 19th centuries. In particular, we must concentrate on the debates in Great Britain and the United States, since Marx and Weber took their ideas from the debates in these countries.
Defenders of slavery in the 18th and 19th centuries liked to point out that slavery had been an undisputed institution of Roman and International Law; they would refer to the fact that neither the Bible nor the Church during later centuries had unequivocally condemned slavery; they could entertain the idea that black people were Hamites who had been eternally condemned to slavery by Noah?s curse or they would claim that black people because of their racial inferiority did meet the criteria of Aristotle?s natural slaves. However, pro-slavery spokesmen were on the defence against the abolitionist movement in the Anglo-Saxon world. This movement was started by Quakers and Mennonites, and then adopted by Methodists and other evangelical groups. They declared slavery as incompatible with the Christian demand for charity. At the same time, they were concerned about the morality of the lower classes in their own society who should get accustomed to honest work instead of indulging in idleness, gambling and drinking. Abolitionism in Britain became a mass movement from the 1780s onwards. By petitions to parliament, press campaigns and boycott actions, it was finally successful. In 1807 slave trade was declared illegal in the British Empire and in 1833 the institution of slavery itself was abolished.
The situation in the United States was quite different. Contemporaries were aware that references to the natural rights of men in the Declaration of Independence, or even in the Bill of Rights of the slaveholder-state Virginia in 1776, implied promises that one would have to fulfil sometime. However, the necessity of preserving the union of the thirteen states prevented the issue from being addressed in the United States Constitution of 1787. The constitution even prohibited Congress from making a federal law against the importation of slaves for a period of twenty years. After this period had expired, the importation of slaves into the United States was prohibited in 1808. Both abolitionists and defenders of slavery expected that slavery would, so to speak, die out in the long run an erroneous assumption. One must note, however, that the impact of abolitionism on politics in Britain and the USA cannot be simply understood as reflecting the superiority of Christian and moral arguments. It was also supported by the assertion that slavery was less productive than formally free labour and thus a stumbling-block to the development of a commercial society that would provide increasing prosperity for all its members. This idea had especially been propagated by the Scottish social scientists of the 18th century.
In his famous essay of 1752, Of the Populousness of Ancient Nations, David Hume stated that slavery corresponded to an economy based on war and booty and thus had prevented population growth and economic progress in antiquity. Hume disputed the number of 400,000 slaves in relation to 21,000 citizens in classical Athens. This figure, allegedly going back to a census of the late 4th century BC, had been transmitted in the collectanea of Athenaeus (272c) in the third century AD. According to Hume, one should read 40,000 since the experience of modern slave societies proved that slave-owners could not keep control of enormous slave masses without resorting to military means. John Millar of Glasgow, in The Origin of the Distinction of Ranks (1779) was convinced ?that the work of a slave, who receives nothing but a bare subsistence, is really dearer than that of a free man, to whom constant wages are given in proportion to his industry?. In The Wealth of Nations, Adam Smith stated in 1776: ?It appears from the experience of all ages and nations, I believe, that the work done by freemen comes cheaper in the end than that performed by slaves?. Fair wages for free labourers fostered productivity and population growth whereas slaves could show no interest in improvements of productivity, since the slave-owner would interpret this as an expression of laziness. That is why, according to Smith, the labour of a slave was necessarily more expensive than that of a free man. These statements were not based on reliable data; remember Adam Smith?s qualification ?I believe?. But they strengthened the abolitionist case as being in accordance with economic rationality. There was, however, an ironic twist in the use of this argument when the slavery issue led to increasing tensions within the United States from the 1820s onwards.
Southern planters liked to assert that their keeping to slavery despite of its economic disadvantages was due to their paternalistic attitude. They boasted to exercise life-long care for the welfare of their subjects whereas northern entrepreneurs practised wage dumping and hired and fired their labourers. George Fitzhugh, a fervent defender of the ?peculiar institution? of the southern states, claimed in 1857:
?Our Southern slavery has become a benign and protective institution, and our negroes are confessedly better off than any free laboring population in the world. [?] We [Southerners] love our slaves, and we are ready to defend, assist and protect them; you [Yankees] hate and fear your white servants, and never fail, as a moral duty, to screw down their wages to the lowest. [?] Free laborers have not a thousandth part of the rights and liberties of negro slaves. Indeed, they have not a single liberty, unless it be the right or liberty to die?.
These debates on the supposed inefficiency of slave labour provided the background to the attempts of Marx and Weber to analyze ancient slavery. In both cases that happened with continuous reference to slavery in the modern world. There are striking similarities in their approach, but the important difference is that Marx and Engels did not develop a theory of ancient economy and slavery whereas Weber laid the foundations for his cross-cultural comparisons by working this out explicitly. Of course, Karl Marx (1818-1883) and Friedrich Engels (1820-1895) were acquainted with antiquity, since a thorough education in classics was fundamental for 19th century German secondary schools and universities. Marx had even obtained a doctoral degree in ancient philosophy; Engels had not enjoyed a completed education, but was an inspired autodidact. Their references to ancient sources and facts are often just a reflection of this cultural tradition. They did not keep up with the growing scholarly literature on antiquity, but relied on some basic works, such as Niebuhr and Mommsen on Roman history, and Böckh and Grote on Greek history.
With some exceptions, there is no coherent treatment of antiquity, but we can find scattered remarks in a number of texts of diverse sorts, from great scholarly works like the Capital, political pamphlets and newspaper articles, to letters. Hence the great problem with many later attempts to construe a Marxist theory of antiquity is that they do so by combining paragraphs, or single sentences even, from different times and with diverse intentions, often quoted without considering the respective contexts, or even selected in such a way that the original line of reasoning is deliberately obscured. Quotations from Marx?s letters and newspaper articles are especially popular because of their often drastic formulations. When read in full, however, they reveal that references to antiquity are in many cases motivated by contemporary events that reminded the author of certain parallels in the ancient world. For example, one of the longest digressions on ancient slavery that Marx ever wrote appeared in a newspaper article on ?Sicily and the Sicilians?. It was published by the New York Daily Tribune in May 1860. This article was written on occasion of the Palermo rising against the Bourbon dynasty. In it, Marx provided a survey of Sicilian resistance to foreign domination through the centuries. The Sicilian slave insurrections during the time of the late Roman Republic were seen as just a part of this continuous struggle throughout history even though Marx thought that in this case a sort of coalition between indigenous population and imported slaves had been achieved. There is also a famous letter Marx wrote to Engels in February 1861. He said that his desperate attempts to solve his financial problems led to the following situation:
?I have read no newspapers whatsoever, not even the Tribune on the American crisis. However, for recreation in the evenings I have been reading Appian?s Civil Wars of Rome in the original Greek. [?] Spartacus emerges as the most capital fellow in the whole history of antiquity. A great general (no Garibaldi), of noble character, a real representative of the proletariat of ancient times; Pompey a real shit [?].?
It is evident that the crisis in the United States and the war of unification in Italy were in the focus of his interest in those days. And Marx?s disparaging remark on Pompey was due to the fact that Pompey had exaggerated his part in crushing the slaves? insurrection as he hade done before with respect to his role in the war against Sertorius.
In the Communist Manifesto of 1848, Marx and Engels had counted the struggle of slaves versus free men as one of those class struggles that had determined the whole course of history. But they did not seriously believe in a class struggle carried out by slaves. In the Capital, Marx stressed that in antiquity class struggle had taken place between creditors and debtors with the result that in ancient Rome plebeian debtors were replaced by slaves as workforce. Engels noted down in 1882 that the slaves had not shown the will to liberate themselves as had been proven by Spartacus?s defeat.
The only statements of systematic importance are those where Marx and Engels tried to integrate classical antiquity into a model of the history of mankind. This holds true for the German Ideology, written in 1845/46, but not published during the authors? lifetime. Drawing on Savigny and Niebuhr, early Roman history is understood as revealing the step from collective to individual property which implied the emergence of chattel slavery. Most famous are some pages Engels wrote in his Anti-Dühring of the late 1870s. Here he declared slavery a necessary step for the course of human progress:
?It was slavery that first made possible the division of labour between agriculture and industry on a larger scale, and with it the glory of the ancient world, Hellenism. Without slavery, no Greek state, no Greek art and science; without slavery, no Roman Empire. But without the basis laid by Hellenism and the Roman Empire, no modern Europe either. We should never forget that our whole economic, political and intellectual development presupposes a state of things in which slavery was as necessary as it was universally recognized. In this sense we are entitled to say: Without the slavery of antiquity, no modern socialism. [?] It is very easy to inveigh against slavery and the like in general terms and pour out the vials of one?s lofty moral wrath on such infamies. [?] But it does not tell us one word as to how these institutions arose, why they existed, and what role they have played in history. When we examine these questions, we are compelled to say [?] that the introduction of slavery under the then prevailing conditions was a great step forward. [?] Economic advance consisted in the increase and the development of production by means of slave labour. This could not be achieved within the crudest form of state, Oriental despotism, from India to Russia.?
In the same context, Engels explained that slavery had developed out of war and had overcome a primordial stage of cannibalism:
?[Labour power] was furnished by war; and war was as old as the coexistence of several groups of juxtaposed communities. Hitherto they had not known what to do with prisoners of war and had therefore simply killed them, at a still earlier day, eaten them. [?] The Prisoners of war, from whom the mass of slaves was recruited, now at least saved their lives, instead of being killed as they had been before, or even roasted, as at a still earlier period.?
The particular items of Engels? argumentation were not original. That enslavement resulted from the victor?s renunciation of his right to kill prisoners of war, was an established tradition from antiquity to early modern theorists like Hugo Grotius or John Locke. That slavery had put an end to cannibalism had been said by the French social scientist Auguste Comte in the 1830s and was later, for example, repeated by the German economic historian Gustav Schmoller in 1900. That slavery, however deplorable, was a necessary precondition for the development of a Greek culture that had provided an eternal heritage for mankind, was the opinion of many classicists such as, for example, August Böckh. But these current ideas were now integrated by Engels into a concept of a progressive development of mankind due to economic necessities which would eventually lead to a new age of socialism. Engels? remarks on the quite different conditions under Oriental Despotism remind us of the famous statement of Marx in his 1859 preface to The Critique of Political Economy:
?At a certain stage of their development, the material productive forces of society come in conflict with the existing relations of production, or what is but a legal expression of the same thing with the property relations within they have been at work hitherto. From forms of development of the productive forces these relations turn into their fetters. Then begins an epoch of social revolution. [?] In broad outlines Asiatic, ancient, feudal, and modern bourgeois modes of production can be designated as progressive epochs in the economic formation of society.?
The attempts of later Marxists to fill out these broad outlines had to struggle with the vexed category of the ?Asiatic mode of production? on the one hand and, on the other, with the ?epoch of social revolution? that should have marked the step from one economic formation to the next one, antiquity to feudalism in our case. I cannot embark on these discussions here. I just want to point out that Marx himself did not develop a theory of ancient economy according with this concept. Engels? hastily written 1884 book on the Origin of the Family, Private Property and the State could not fill this gap. It is also a sign for a shift of interest towards the primordial stages of social organisation which allegedly could be reconstructed by the ethnological evidence collected by Lewis Henry Morgan. With respect to slavery in classical antiquity, this piece of Engels has often been quoted and heavily criticized because Engels seemed to accept the enormous number of slaves in Athens which had been reported by Athenaeus. This is not that surprising as was often supposed, since Hume?s correction of this famous figure had not been generally accepted. Several 19th century classicists kept to the traditional number. But Engels did not speak of 400,000 but of 365,000 slaves as a matter of fact. That clearly indicates his source: August Böckh?s Staatshaushaltung der Athener, firstly published in 1817. Böckh had meant that Athenaeus? figure needed a certain rounding off and thus conjectured this slightly lower figure. The fact that Engels had just accepted Böckh?s suggestion seems to have passed unnoticed by later critics of Engels.
A closer look on Marx?s scattered remarks on ancient slavery reveals that they are almost all by-products of his interest in the American slave debate. Since Marx, especially in the Capital, provided long quotations from the works he had perused it is easy to see that he relied on abolitionist literature of the mid-nineteenth century in which the older argument of an inherent unproductiveness of slave-labour was repeated and expanded. That holds especially true for the writings of Frederick Law Olmsted and John Elliott Cairnes. Olmsted became known later as a landscape architect who, for example, designed New York?s Central Park. In the years 1852-1855 he regularly published reports from his journeys in the southern states of the USA in the New York Times, and two books also later based on these materials. Olmsted accepted the self-representation of southern slave-owners as benevolent patrons who took care of their slaves without regard to financial costs and thus he considerably underrated the profits made by southern planters.
Olmsted?s impressions were elevated to the heights of economic theory by John Elliott Cairnes. In 1862, the Irishman Cairnes, then professor of political economy at Queen?s College Galway, published his book Slave Power. In this book he used Olmsted?s reports as a basis for his assessment of the slave economy of the ante-bellum south. Cairnes coined impressive phrases to underline the economic disadvantages of slavery:
?[Slave labour] is given reluctantly; it is unskilful; it is wanting in versatility. It is given reluctantly, and consequently the industry of the slave can only be depended on so long as he is watched. [?] Secondly, slave labour is unskilful, and this, not only because the slave, having no interest in his work, has no inducement to exert his higher faculties, but because, from the ignorance to which he is of necessity condemned, he is incapable of doing so. [?] But further, slave labour is eminently defective in point of versatility. The difficulty of teaching the slave anything is so great, that the only chance of turning his labour to profit is, when he has once learned a lesson, to keep him to that lesson for life. Where slaves, therefore, are employed there can be no variety of production.?
In his Capital, Marx gave a long quotation from Cairnes that the extreme exhaustion of the slaves? capacity for work would imply the necessity for a steady supply of new labour forces by slave trade. Marx mentioned the parallels of slaves in ancient mines but stated that their case represented an exception in the ancient world. Nevertheless, he implied that the American example would indicate that any slave economy would depend on continuous slave supply from abroad. From Olmsted, or from Cairnes who had quoted Olmsted, Marx took over the so-called theory of sabotage. One could give only primitive tools to slaves since they would destroy better equipment; one could only entrust mules to them because mules, in contrast to horses, would survive mistreatment by the slaves. This sabotage theory was to play an important role in later Marxist writings on antiquity; it should, however, be stressed that Marx did not say that it applied also to antiquity.
Marx?s interest in American slavery was also motivated by the observation that the employment of black slaves went hand in hand with the growth of a white under-class that was not prepared to accept work normally done by slaves. Cairnes had stated that the existence of such a ?poor white trash? was the ?invariable outgrowth of negro slavery wherever it has raised its head in modern times?. Olmsted had written:
?No white man would ever do certain kinds of work [?]; and if you should ask a white man you have hired to do such things, he would get mad and tell you he wasn?t a nigger. [?] The poor white seem [?], more than any other portion of the community, to hate and despise the negroes?.
This attitude of poor whites was in Marx?s eyes responsible for the lack of a labour movement in the United States. That is why he sent on behalf of the International Workingmen?s Association a congratulation address to President Abraham Lincoln in December 1864. He expressed the confidence that the abolition of slavery would enable the formation of a self-conscious working class in the United States.
In theoretical terms, Marx was interested in American slave economy since it constituted an ?anomaly in a world economy based on free labour?. It was the central aim of Marx?s lifework to detect the laws that governed modern capitalist economy. This economy is fundamentally distinct from all previous forms because it employs a labour force on formally free contract. In this respect, Antiquity was of only marginal interest. Marx mocked at Mommsen?s use of the term ?capitalism? with regard to the Roman world since such a usage would obscure the fundamental difference between pre-modern periods and the modern world. It is a credit to Marx?s intellectual honesty that he always made clear which period he was talking about, and that he was remarkably reluctant to draw inferences from the modern evidence (as he understood it) with respect to the ancient world. Later Marxism, especially under the guidance or threat of official doctrines, was of a quite different sort.
Max Weber (1864-1920) has often been called ?the bourgeois Marx?. In a sense, this label coincides with Weber?s self-image since he considered Marx?s theory as a fundamental intellectual challenge. He accepted that one should take an economic interpretation of history very seriously, but warned that one should not underrate the blending of cultural and economic factors, nor subscribe to a philosophy of history that postulated laws of development in analogy to natural laws. And Weber, like Marx, boasted of analyzing economic processes without indulging in moralizing. Since sociology was not yet an established academic discipline in his days, Weber had received his scholarly education as an economic and legal historian, and devoted a large part of his early work to the study of Greco-Roman Antiquity. Indeed, the great Theodor Mommsen was so impressed by the theses on Roman agrarian history which Weber presented at his doctoral disputation in 1889 that he claimed he could not think of a better successor than Max Weber. Weber took up these ideas in his Römische Agrargeschichte, published in 1891. Furthermore, he wrote a sweeping article on Die sozialen Gründe des Untergangs der antiken Kultur in 1896 and a book-length survey of Agrarverhältnisse im Altertum in 1909. Later, he also made numerous, if scattered references to Antiquity in his Wirtschaft und Gesellschaft [Economy and Society] and in his collection of articles on the sociology of world religions. Finally, there is the so-called Wirtschaftsgeschichte [General Economic History] which is a reconstruction of Weber?s Munich university lectures of 1919/20, based on notices of hearers.
Weber, like Marx, stressed the singularity of modern capitalism, but he wanted to analyze its peculiarity by cross-cultural comparisons, at first with classical antiquity, later also with the great cultures of Asia. Weber insisted, pace Eduard Meyer?s interpretation of slavery, on the fundamental difference between manufactures based on slave labour and an industry organized on a qualitative division of labour and making use of a formally free labour force. ?Nothing could be more misleading, therefore, than to describe the economic institutions of Antiquity in modern terms?. Somewhat surprisingly, Weber nevertheless claimed that one should speak of an ancient capitalism. He asserted that capitalism should be defined in economic terms only, in the sense that ?property is an object of trade and is utilized by individuals for profit-making enterprise in a market economy?. One should not ?needlessly? include the social factor characteristic of modern capitalism, that is ?the exploitation of other people?s labour on a contractual basis?, in a general definition. Apparently, Weber wished to preserve a universally applicable category of capitalism. This category should not blur the structural differences between cultures and epochs but enable a differentiation of the phenomena of ancient, premodern and non-European capitalism, based on war and booty, state monopolies, tax-farming, or trade from the specific modern and ?rational? capitalism.
Weber?s Römische Agrargeschichte had heavily drawn on Mommsen?s Römische Geschichte for its general picture of Roman agrarian capitalism. When Weber later included Greece and the Ancient Near East in his analysis, he relied on Eduard Meyer?s Geschichte des Altertums, but also on a great number of other scholarly works. And he was acquainted with the relevant ancient sources. In his 1896 essay and his Agraverhältnisse im Altertum he developed a theory of ancient economy by which he sought to explain how the development of ancient capitalism was limited by the basic political structures of antiquity and was finally ?strangled? during the Roman Empire. The assessment of the fate of slavery was an essential part of this story.
A summary of Weber?s views on ancient slavery would read like this: Chattel slavery is one of the inherent causes for the structural weakness of ancient capitalism. It entailed economic disadvantages in comparison to free labour, since slaves have to be fed continually and the owner had to take the risk of mortality. The lack of a free labour force that could have been employed only during the peak times of the agricultural year led to an overemployment of slaves on the great landed estates. That meant in turn that slaves were also employed to make manufactured products. Thus, the development towards market economy was undermined. There were no inducements to technological progress. Great variations of prices for slaves due to changing political circumstances made it impossible to calculate the costs of labour. Full exploitation of the slaves? labour capacity implied that slaves had to be kept in slave barracks and could not be allowed to have families. That in turn meant that the slave system depended on steady supply of new slaves by the slave market. And this precondition was no longer given when the expansion of the Roman Empire had come to an end:
?The barracks demanded constant replenishment; hence new slaves had to be continually purchased. [?] The ancient plantation consumed slaves the way a modern blast furnace consumes coal. Hence a slave market regularly and amply supplied with human material was the indispensable precondition for a barracks slave system engaged in market production. [?] But what if the market failed to find these supplies? This would inevitably affect the slave barracks, just as today closing the coal mines would affect the blast furnaces. [?] But after the final offensives wars of the second century, which were in fact little more than slave raids, it became impossible to maintain the great plantations worked by slaves without family and without property?.
Whatever the merits or shortcomings of this analysis, Weber was obviously convinced that two factors applied to slavery in all epochs of history. Firstly, that slave labour was necessarily less productive than contract labour, and, secondly, that a slave population could not be reproduced by breeding. These assumptions are especially revealed by passages in Wirtschaft und Gesellschaft and in Wirtschaftsgeschichte. In both texts, or better, bundles of papers, Weber developed an ideal type of ?plantation economy? based on large gangs of barracked slaves that should apply to ancient Carthage and Rome as well as to the southern states of the USA and to the Caribbean. In this context, Weber asserts that slavery was doomed to extinction in the USA after the prohibition of slave imports in 1808 which had entailed the same consequences as the end of Roman expansionist policies. Thus, the abolition of slavery in course of the American Civil War was only the political ratification of an inevitable economic necessity.
It is astonishing that Weber, who had always shown an incredible capacity to keep up with the scholarly literature of a great number of disciplines, ignored a fact that was well-known in his days: in the twenty years between the ratification of the American Constitution and the prohibition of the importation of slaves the number of slaves had achieved a first peak which was outmatched due to a natural reproduction that had been carefully directed by slave-holders in the following period. The number of slaves in the USA had grown from seven-hundred thousand in 1790 to one million and two-hundred thousand in 1810, and four millions in 1860, despite of the progressive abolition of slavery in northern states. This was due to the fact that southern slaveholders had paid attention to an equal ratio of sexes and fostered family unions. That was possible because women could be employed as work force on cotton plantations. And cotton plantations were of moderate size. Work-forces of twenty to fifty slaves did not demand a barrack system. This constellation was quite different from that on sugar plantations in the Caribbean where only male workers were employed and often worked to death.
In his digressions on plantation economy, Weber seems to ignore these differences between diverse historical phenomena in antiquity, the USA and the Caribbean. He does not discuss the differences with respect to the nature of the agricultural products, the size of work-forces, the organization of work, the methods of disciplining slaves, the fostering of slave-families, and so on. This is the more astonishing since usually Weber?s development of universally applicable ideal-types was accompanied by long digressions on the actual differences between cultures and epochs, and these were often substantially longer than the passages on their common features. With respect to slave economy, Weber appears to have lost sight of the great differences. He seems to have drawn a rule from antiquity that a slave population cannot reproduce itself, and a rule from modernity that slave labour is less efficient than free labour, and then assumed both rules to be universally valid laws. I can offer no really satisfactory explanation for this blind spot. One suggestion, however, may be that with respect to the presupposed economic inefficiency of slavery Weber followed assertions proposed by authors like Olmsted and Cairnes. Thus, Weber accepted the ?theory of sabotage? and the notion of the ?poor white trash? and drew parallels with antiquity in both respects. With regard to the alleged structural similarities between ancient and modern slavery, Weber also took notice of the writings of the ancient historian Ettore Ciccoti and the economist Achille Loria, both in the 1890s. Both Italian scholars considered themselves as Marxists. Following Marx?s lead, both had read Cairnes and tried to apply his theories to antiquity.
All in all, neither Marx?s nor Weber?s views on slavery in general and ancient slavery in particular can be understood without considering the influence of abolitionist assertions of the 19th century. Since the new debate on ante-bellum American slavery inaugurated by the ?cliometric? work of Fogel and Engerman in the 1970s, we now know that the assumption of the inefficiency of slave economy in the American southern states is wrong or, to put it in extremely cautious terms, cannot be proven. Abolitionist argumentation relied on an economic myth but it is not so often that economic myths have charitable consequences. And even our intellectual giants who liked to assert that they were, and were later assumed to have been, immune from confusing economic and moral arguments, accepted this myth.
* Paper presented at University College Dublin, 18 November 2004. References are kept to a minimum. An expanded German version with full documentation will appear in: E. Herrmann-Otto (ed.), Unfreie Arbeits- und Lebensverhältnisse von der Antike bis zur Gegenwart (Hildesheim, 2005).
 In D. Hume, The Philosophical Works, ed. Th. H. Green and Th. H. Rose, vol. III (London, 1882), 381-463.
 Chapter VI, (4th ed. 1806; repr. Aalen, 1986), 255.
 Book I, chapter VIII. Ed. R. H. Campbell and A. S. Skinner, vol. I (Indianapolis, 1981), 99.
 G. Fitzhugh, Cannibals All! Or: Slaves without masters, ed. C. Vann Woodward (Cambridge, Mass., 1988) 201, 220 and 19.
 For Marx?s and Engels? writings I refer to Karl Marx/Friedrich Engels, Werke (Berlin, 1955 ff.) = MEW henceforth. English quotations are taken from Marx/Engels, Collected Works, 1975ff., available at http://www.marxists.org.
 MEW 20, 167 and 169.
 MEW 21, 116 and 166.
 3rd ed. (Berlin, 1886), vol. I, 47-49.
 F. L. Olmsted, A Journey in the Seaboard Slave States, with Remarks on their Economy (New York, 1856); The Cotton Kingdom. A traveller?s observation on cotton and slavery in the American slave states (1861), ed. A. M. Schlesinger (Cambridge, Mass., 1996).
 J.E. Cairnes, The Slave Power. Its character, career and probable designs, 2nd. ed. (1863; repr. Columbia, SC, 2003), 44-47.
 MEW 23, 210, n. 117.
 MEW 15, 337; 19, 111f.; 21, 144; 22, 463.
 Cairnes, Slave Power, 82f.
 Olmsted, Cotton Kingdom, 64-66.
 MEW 23, 182, n. 39; 25, 339, n. 46; 25, 795 with n. 43.
 See especially Weber?s programmatic statement of 1904, in M. Weber, Gesammelte Aufsätze zur Wissenschaftslehre (Tübingen, 1973), 166f.
 See J. Deininger in M. Weber, Die Römische Agrargeschichte in ihrer Bedeutung für das Staats- und Privatrecht, ed. J. Deininger (Tübingen, 1986) (Max Weber Gesamtausgabe I/2), 57f.
 Both texts are reprinted in M. Weber, Gesammelte Aufsätze zur Sozial- und Wirtschaftsgeschichte (Tübingen, 1924), 289-311 and 1-288, respectively. The English translation of Agrarverhältnisse (The Agrarian Sociology of Ancient Civilizations, trans. R. I. Frank (London, 1978)) also contains the 1896 essay (The Social Causes of the Decline of Ancient Civilization).
 E. Meyer, ?Die Sklaverei im Altertum?, in Kleine Schriften, 2nd. ed. (Halle, 1924), vol. I, 169-212.
 Agrarian Sociology, 45.
 Agrarian Sociology, 50f.
 Social Causes, in Agrarian Sociology, 398f.
 Wirtschaft und Gesellschaft, 5th ed. (Tübingen, 1972), 85, 94f. and 524.
 Wirtschaftsgeschichte (München, 1923), 82-86.
 Wirtschaft und Gesellschaft, 415.
 For example, Wirtschaftsgeschichte, 85.
 E. Ciccotti, Il tramonto della schiavitù nel mondo antico (Torino, 1899); A. Loria, ?Die Sclavenwirthschaft im modernen Amerika und im europäischen Alterthume?, Zeitschrift für Social- und Wirtschaftsgeschichte 4 (1896), 67-118, both quoted by Weber, Agrarian Sociology, 370.
 R.W. Fogel and S.L. Engerman, Time on the Cross. The Economics of American Negro Slavery (London, 1974).