Das Kapital

Extended reproduction — the conversion of surplus-value into new capital — forms the subject of Marx's analysis here. This is accumulation proper: not consuming surplus-value as revenue but reinvesting it to expand the scale of production. Marx traces the logical consequence of this process over time. The spinner who begins with £10,000 and extracts £2,000 in surplus-value reinvests it, expanding to £12,000. After enough cycles, the entire capital in operation was produced from surplus-value — from past unpaid labour. The original sum advanced has been repaid many times. What the capitalist now commands is not personal savings or prior sacrifice but accumulated expropriation. The legal title to property, which appears to rest on past labour and legitimate savings, rests in fact on the systematic appropriation of others' labour. This produces an apparent paradox. The laws of commodity exchange — equal exchange, voluntary transaction, fair price — seem to govern capitalist production. And at each individual moment, they do: the worker is paid the full value of their labour-power. But the cumulative effect of repeated equal exchanges is profoundly unequal: capital grows without bound while the worker returns each morning with nothing but labour-power to sell. The laws of property that govern simple commodity exchange transform, through accumulation, into laws of capitalist appropriation. Marx disposes of two justifications for this outcome. The abstinence theory (Senior) claims capitalists deserve profit as compensation for not consuming their wealth. Marx notes that the 'abstinence' that yields £2,000 in surplus is performed by the worker who receives £90 in wages — the capitalist's self-denial is largely invisible next to that. The labour fund theory holds that a fixed pool of capital determines how much can be paid in wages. Marx shows this fund is itself created by labour and merely describes the outcome of a prior distribution rather than explaining it.