In order to simplify the matter (since we shall not discuss the
 merchant as a capitalist and merchant’s capital until later) we shall assume
 that this buying and selling agent is a man who sells his labour. He expends
 his labour-power and labour-time in the operations C — M and M — C. And
 he makes his living that way, just as another does by spinning or making
 pills. He performs a necessary function, because the process of reproduction
 itself includes unproductive functions. He works as well as the next man,
 but intrinsically his labour creates neither value nor product. He belongs
 himself to the faux frais of production. His usefulness does not
 consist in transforming an unproductive function into a productive one,
 nor unproductive into productive labour. It would be a miracle if such
 transformation could be accomplished by the mere transfer of a function.
 His usefulness consists rather in the fact that a smaller part of society’s
 labour-power and labour-time is tied up in this unproductive function.
 More. We shall assume that he is a mere wage-labourer, even one of the
 better paid, for all the difference it makes. Whatever his pay, as a wage-labourer
 he works part of his time for nothing. He may receive daily the value of
 the product of eight working-hours, yet functions ten. But the two hours
 of surplus-labour he performs do not produce value anymore than his eight
 hours of necessary labour, although by means of the latter a part of the
 social product is transferred to him. In the first place, looking at it
 from the standpoint of society, labour-power is used up now as before for
 ten hours in a mere function of circulation. It cannot be used for anything
 else, not for productive labour. In the second place however society does
 not pay for those two hours of surplus-labour, although they are spent
 by the individual who performs this labour. Society does not appropriate
 any extra product or value thereby. But the costs of circulation, which
 he represents, are reduced by one-fifth, from ten hours to eight. Society
 does not pay any equivalent for one-fifth of this active time of circulation,
 of which he is the agent. But if this man is employed by a capitalist,
 then the non-payment of these two hours reduces the cost of circulation
 of his capital, which constitutes a deduction from his income. For the capitalist this is a positive gain, because the negative limit for the self-expansion
 of his capital-value is thereby reduced. So long as small independent producers
 of commodities spend a part of their own time in buying and selling, this
 represents nothing but time spent during the intervals between their productive
 function or diminution of their time of production.