Although one of the least developed Marxist concepts, slave mode or organization of productive relations has spawned rich intellectual debate. There are four major lines of inquiry. Must the number of productive workers be the dominant form of labor? What is the significance of surplus extraction (profit through exploitation) in the organization of production, and how does it define a social formation? Is there one mode of production or several competing social formations at any one time? What was the historical evolution of the slave mode of production?
Although Karl Marx’s primary concern was with the historical evolution of capitalism, not pre-capitalist social formations, he occasionally referred to the slave mode of production. The German Ideology identified the first historical form of property as communal, containing within it familial and slave relations (1978, p. 151). The Communist Manifesto recognized three forms of class society: capitalist and proletarian during the bourgeois epoch, lord and serf during feudalism, and master and slave during antiquity (1978, p. 474). The Grundrisse described the second system of historical development as antiquity characterized by dynamic, urban, warlike conditions, with chattel-slave relations (1965, pp. 36, 71-75). Despite these references, Marx provided little conceptual explanation for the origins and nature of slavery. In contrast to his analysis of the conditions of modern capitalism, he gave little attention to the internal dynamic of the slave mode of production and how this mode rises out of past social formations and dissolves under new historical conditions.
SLAVES IN ANTIQUITY
Unlike Marx, scholars of antiquity have long debated the nature of classical slavery. According to Moses Finley, slavery was insignificant both temporally and geographically in the Greco-Roman world. The dominant labor force produced under various degrees of "unfreedom" in a society with different relations of production. The key question, concludes Finley, is "whether the relations of production were sufficiently different to preclude the inclusion of such societies within a single social formation in which the slave mode of production was dominant" (1991, p. 496). On the one hand, Ellen Meiksins Wood argues that peasant-citizens rather than slaves constituted the productive basis of Athenian democracy and that forms of tenancy, leasing, and management, not slavery, formed the basis for surplus extraction (1988, pp. 64-82). Geoffrey E. M. de Ste. Croix agrees that non-slave producers accounted for the demographic majority during antiquity, but argues that the dominant form of exploitation was slavery because slaves provided the surplus extraction for a wealthy elite. According to Ste. Croix, Marx’s concentration on the distinctive feature of society "is not the way in which the bulk of the labour of production is done, but how the extraction of surplus from the immediate producer is secured" (1981, p. 52). It was slavery’s increase in surplus extraction that accounts for "the magnificent achievements of Classical civilization" (1981, p. 40). Perry Anderson agrees on the importance of slave surplus extraction during antiquity, although he argues that the imperial state played a more important role in organizing the actual process of extraction (1992, pp. 19-22).
Another key question concerns the historical evolution of ancient slavery into new social formations. Marx simply described the movement of "progressive epochs in the economic formation of society" (1978a, p. 5). In contrast, Ste. Croix explains that slavery as the most efficient form of surplus extraction was transformed once Roman frontiers stabilized and the number of war-supplied slaves trailed off. The consequence was increased slave-breeding as landowners sought to maintain their labor force. The crucial factor was female slave reproduction over slave production. To make up for the lost surplus, landowners extended exploitation to hitherto free laborers, with the result of the emergence of a uniform class of coloni whose rate of exploitation was down, but volume had expanded. Thus, the ancient world was destroyed by a social crisis from within and finished off by the so-called barbarians from without (1991, p. 503). Anderson agrees on the internal social crisis but pays equal attention to external factors. "The dual predecessors of the feudal mode of production," he argues, "were the decomposing slave mode of production on whose foundations the whole enormous edifice of the Roman Empire had once been constructed, and the distended and deformed primitive modes of production of the Germanic invaders" (1974, pp. 18-19).
NEW WORLD SLAVES
Although Marx’s own historical moment was dominated by the capitalist mode of production, slavery was not a peculiar institution in the mid-nineteenth century. When Marx was forty-two years old in 1860, there were about six million enslaved Africans in the New World, two-thirds of whom were imprisoned in the American South. Numerous scholars have debated this duality. Eugene Genovese argues that southern slavery was in conflict with capitalism and created a "powerful and remarkable social class" (1967, pp. 3-4). In contrast, John Blassingame has focused upon slave non-productive relations, especially communal and cultural formations. Other scholars insist on the centrality of productive relations. Ira Berlin and Philip Morgan insist that work "engaged most slaves, most of the time" (1993, p. 1). Still others insist on the exploitative nature of slavery and the role of surplus extraction. Eric Williams argued that slavery built up capitalism, while capitalism destroyed slavery. Robin Blackburn has recently argued that the profits from colonial slavery’s surplus extraction—what he dubs "extended primitive accumulation"—fueled Britain’s remarkable industrial takeoff. The passage from pre-modern to modern society was not that of the classic Marxist transformation of agrarian property relations, but rather "exchanges with the slave plantations helped British capitalism to make a breakthrough to industrialism and global hegemony ahead of its rivals" (1997, p. 572). Unlike economic arguments for the shift from antiquity to feudalism, political explanations for passages from slavery to modernity, especially slave revolts in the New World, have been persuasively made by W. E. B. Du Bois, C. L. R. James, Robin Blackburn, and others.
SLAVES IN AFRICA
The debates on slave surplus extraction, competing social formations, and historical evolution have been extended to Asia and Africa. Walter Rodney argues that there was no "epoch of slavery" in pre-fifteenth-century Africa because of the absence of "perpetual exploitation." He prefers the notion of competing social formations to one mode of production with pre-colonial Africa in transition from communal agriculture to feudalism (1982, p. 38). Claude Meillassoux agrees that the absence of perpetual "relations of exploitation and the exploiting class" ensured there was no system of slavery in Africa and that there were several social formations (1991, pp. 36, 235). But he goes further. Slavery was not only a relationship of production, but also a "mode of reproduction" (1991, p. 324). In contrast to Ste. Croix’s argument for antiquity, this reproductive slavery had little to do with procreation and much more to do with the economy of theft through war, abduction, and brigandage (1991, pp. 76, 92). "Wars of capture and markets," Meillassoux argues, "had their counterpart in the sterility of the women slaves who, despite their sex and their numbers, were deprived of reproductive functions" (1991, pp. 85, 278). Although John Thornton does not subscribe to Marxist concepts such as mode of production and surplus extraction, he does insist on the centrality of slavery to the continent’s historical development, and his argument has been quite influential. Specifically, ownership or control of labor (in contrast to land ownership in feudal Europe) was the dominant principle of property relations in African societies, and "slavery was rooted in deep-seated legal and institutional structures of African societies" (1998, p. 74). This view has been correctly criticized for downplaying the qualitative change wrought by the advent of the Atlantic slave trade.
Returning to the lines of inquiry above, there are some key points. The number of productive workers does not have to be dominant. This was as true of slaves in antiquity as of slaves in the New World. Surplus extraction is critical to particular social formations.
Slaves in antiquity and the New World helped build magnificent civilizations. Slavery is a modern as well as an ancient social formation. Kevin Bales counts twenty-seven million slaves today operating as part of the global economy (1999, p. 9). Slavery plays a role in the historical evolution of social formations in terms of both reproduction and production. There is no one passage from slavery into other social formations.