[A]s the costs of producing labouring powers of different quality do differ, so must differ the values of the labouring powers employed in different trades. The cry for an equality of wages rests, therefore, upon a mistake, is an inane wish never to be fulfilled. It is an offspring of that false and superficial radicalism that accepts premises and tries to evade conclusions. Upon the basis of the wages system the value of labouring power is settled like that of every other commodity; and as different kinds of labouring power have different values, or require different quantities of labour for their production, they must fetch different prices in the labour market. To clamour for equal or even equitable retribution on the basis of the wages system is the same as to clamour for freedom on the basis of the slavery system. What you think just or equitable is out of the question. The question is: What is necessary and unavoidable with a given system of production?