The Two Faces of Labor — Das Kapital

Marx now sorts the ingredients of production by how they behave in value terms. Means of production transfer their existing value to the product as they are used up; Marx calls this constant capital. Labour-power, by contrast, reproduces its own equivalent and then adds surplus-value; this outlay is variable capital.

The distinction is not about fixed versus circulating assets in bookkeeping alone. It tracks a social fact: only living labour creates new value, while dead labour in materials and machines merely passes along what it already contains. Marx uses vivid images of value deserting one body to inhabit another, often behind the worker's back, until a crisis makes the transfer brutally visible.

The chapter ends by stressing how appearances deceive. The product seems to owe its full worth to every input equally, which tempts observers to treat wages, wood, and machinery as parallel costs. Marx's labels are meant to break that symmetry and keep sight of where exploitation actually enters.