of the owner of the commodity, first in the shape of his own commodity, then in the form of the money for which he exchanged it, and lastly, in the shape of the commodity he buys with that money. This change of form does not imply a change in the magnitude of the value. But the change, which the value of the commodity undergoes in this process, is limited to a change in its money-form. This form exists first as the price of the commodity offered for sale, then as an actual sum of money, which, however, was already expressed in the price, and lastly, as the price of an equivalent commodity. This change of form no more implies, taken alone, a change in the quantity of value, than does the change of a £5 note into sovereigns, half sovereigns and shillings. So far therefore as the circulation of commodities effects a change in the form alone of their values, and is free from disturbing influences, it must be the exchange of equivalents. Little as Vulgar-Economy knows about the nature of value, yet whenever it wishes to consider the phenomena of circulation in their purity, it assumes that supply and demand are equal, which amounts to this, that their effect is nil. If therefore, as regards the use-values exchanged, both buyer and seller may possibly gain something, this is not the case as regards the exchange-values. Here we must rather say, "Where equality exists there can be no gain."⁵ It is true, commodities may be sold at prices deviating from their values, but these deviations are to be considered as infractions of the laws of the exchange of commodities⁶, which in its normal state is an exchange of equivalents, consequently, no method for increasing value.⁷

Hence, we see that behind all attempts to represent the circulation of commodities as a source of surplus- value, there lurks a quid pro quo, a mixing up of use-value and exchange-value. For instance, Condillac says: "It is not true that on an exchange of commodities we give value for value. On the contrary, each of the two contracting parties in every case, gives a less for a greater value. ... If we really exchanged equal values, neither party could make a profit. And yet, they both gain, or ought to gain. Why? The value of a thing consists solely in its relation to our wants. What is more to the one is less to the other, and vice versâ. ... It is not to be assumed that we offer for sale articles required for our own consumption. ... We wish to part with a useless thing, in order to get one that we need; we want to give less for more. ... It was natural to think that, in an exchange, value was given for value, whenever each of the articles exchanged was of equal value with the same quantity of gold. ... But there is another point to be considered in our calculation. The question is, whether we both exchange something superfluous for something necessary."⁸We see in this passage, how Condillac not only confuses use-value with exchange-value, but in a really childish manner assumes, that in a society, in which the production of commodities is well developed, each producer produces his own means of subsistence, and throws into circulation only the excess over his own requirements.⁹ Still, Condillac's argument is frequently used by modem economists, more especially when the point is to show, that the exchange of commodities in its developed form, commerce, is productive of surplus-value. For instance, "Commerce ... adds value to products, for the same products in the hands of consumers, are worth more than in the hands of producers, and it may strictly be considered an act of production."¹⁰ But commodities are not paid for twice over, once on account of their use-value, and again on account of their value. And though the use-value of a commodity is more serviceable to the buyer than to the seller, its money-form is more serviceable to the seller. Would he otherwise sell it? We might therefore just as well say that the buyer performs "strictly an act of production," by converting stockings, for example, into money.

If commodities, or commodities and money, of equal exchange-value, and consequently equivalents, are exchanged, it is plain that no one abstracts more value from, than he throws into, circulation. There is no creation of surplus-value. And, in its normal form, the circulation of commodities demands the exchange of equivalents. But in actual practice, the process does not retain its normal form. Let us, therefore, assume an exchange of non-equivalents.

In any case the market for commodities is only frequented by owners of commodities, and the power which these persons exercise over each other, is no other than the power of their commodities. The material variety of these commodities is the material incentive to the act of exchange, and makes buyers and sellers mutually dependent, because none of them possesses the object of his own wants, and each holds in his hand the object of another's wants. Besides these material differences of their use- values, there is only one other difference between commodities, namely, that between their bodily form