579Under the conditions of accumulation supposed thus far, which
 conditions are those most favourable to the labourers, their relation of
 dependence upon capital takes on a form endurable or, as Eden says: “easy
 and liberal.” Instead of becoming more intensive with the growth of
 capital, this relation of dependence only becomes more extensive,
 i.e., the sphere of capital’s exploitation and rule merely
 extends with its own dimensions and the number of its subjects. A larger part
 of their own surplus-product, always increasing and continually transformed
 into additional capital, comes back to them in the shape of means of payment,
 so that they can extend the circle of their enjoyments; can make some additions
 to their consumption-fund of clothes, furniture, &c., and can lay by small
 reserve funds of money. But just as little as better clothing, food, and
 treatment, and a larger peculium, do away with the exploitation of the slave,
 so little do they set aside that of the wage worker. A rise in the price of
 labour, as a consequence of accumulation of capital, only means, in fact, that
 the length and weight of the golden chain the wage worker has already forged
 for himself, allow of 580a relaxation of the tension of it. In the
 controversies on this subject the chief fact has generally been overlooked,
 viz., the differentia specifica 
 {defining characteristic} of capitalistic production. Labour power
 is sold today, not with a view of satisfying, by its service or by its product,
 the personal needs of the buyer. His aim is augmentation of
 his capital, production of commodities containing more labour than he pays for,
 containing therefore a portion of value that costs him nothing, and that is
 nevertheless realised when the commodities are sold. Production of
 surplus-value is the absolute law of this mode of production. Labour power is
 only saleable so far as it preserves the means of production in their capacity
 of capital, reproduces its own value as capital, and yields in unpaid labour a
 source of additional capital. [7]
 The conditions of its sale, whether more or less favourable to the labourer,
 include therefore the necessity of its constant re-selling, and the constantly
 extended reproduction of all wealth in the shape of capital. Wages, as we have
 seen, by their very nature, always imply the performance of a certain quantity
 of unpaid labour on the part of the labourer. Altogether, irrespective of the
 case of a rise of wages with a falling price of labour, &c., such an
 increase only means at best a quantitative diminution of the unpaid labour that
 the worker has to supply. This diminution can never reach the point at which it
 would threaten the system itself. Apart from violent conflicts as to the rate
 of wages (and Adam Smith has already shown that in such a conflict, taken on
 the whole, the master is always master), a rise in the price of labour
 resulting from accumulation of capital implies the following alternative: