But it is quickly apparent on closer inspection that this is mere illusion.
 Assuming capitalist production to be predominant, commercial profit cannot be
 realised in this manner. (It is here always a question of averages, not of
 isolated cases.) Why do we assume that the merchant can realise a profit of no
 more than, say, 10% on his commodities by selling them 10% above their price of
 production? Because we assume that the producer of these commodities, the
 industrial capitalist (who appears as "the producer" before the
 outside world, being the personification of industrial capital), had sold them
 to the dealer at their prices of production. If the purchase price of
 commodities paid by the dealer is equal to their price of production, or, in
 the last instance, equal to their value, so that the price of production or, in
 the last instance, the value, represent the merchant's cost-price, then,
 indeed, the excess of his selling price over his purchase price — and
 this difference alone is the source of his profit — must be an excess of
 their commercial price over their price of production, so that in the final
 analysis the merchant sells all commodities above their values. But why was it
 assumed that the industrial capitalist sells his commodities to the merchant at
 their prices of production? Or rather, what was taken for granted in that
 assumption? It was that merchant's capital did not go into forming the general
 rate of profit (we are dealing with it as yet only in its capacity of
 commercial capital). We proceeded necessarily from this premise in discussing
 the general rate of profit, first, because merchant's capital as such did not
 exist for us at the time, and, second, because average profit, and hence the
 general rate of profit, had first to be developed as a levelling of profits or
 surplus-values actually produced by the industrial capitals in the different
 spheres of production. But in the case of merchant's capital we are dealing
 with a capital which shares in the profit without participating in its
 production. Hence, it is now necessary to supplement our earlier exposition.