To comprehend, in the case of each individual capitalist, that a portion of his product must be transformed again into capital (even aside from the expansion of reproduction, or accumulation), indeed not only into variable capital, which is destined to again become in its turn income for the labourers, thus a form of revenue, but also into constant capital, which can never be transformed into revenue — such discernment is naturally extraordinarily easy. The simplest observation of the process of production shows this clearly. The difficulty first begins as soon as the process of production is viewed as a whole. The value of the entire portion of the product which is consumed as revenue in the form of wages, profit and rent (it is entirely immaterial whether the consumption is individual or productive), indeed, completely resolves itself under analysis into the sum of values consisting of wages plus profit plus rent, that is, into the total value of the three revenues, although the value of this portion of the product, just like that which does not enter into revenue, contains a value portion = C, equal to the value of the constant capital contained in these portions, and thus prima facie cannot be limited by the value of the revenue. This circumstance which, on the one hand, is a practically irrefutable fact, on the other hand, an equally undeniable theoretical contradiction presents a difficulty which is most easily circumvented by the assertion that commodity-value contains another portion of value, merely appearing to differ, from the standpoint of the individual capitalist, from the portion existing in the form of revenue. The phrase: that which appears as revenue for one constitutes capital for another, relieves one of the necessity for any further reflection. But how, then, the old capital can be replaced when the value of the entire product is consumable in the form of revenue; and how the value of the product of each individual capital can be equal to the value sum of the three revenues plus C, constant capital, whereas the sum of the values of the products of all capitals is equal to the value sum of the three revenues plus 0 — this appears, of course, as an insoluble riddle and must be solved by declaring that the analysis is completely incapable of unravelling the simple elements of price, and must be content to go around in a vicious circle making a spurious advance ad infinitum. Thus, that which appears as constant capital may be resolved into wages, profit and rent, but the commodity-values in which wages, profit and rent appear, are determined in their turn by wages, profit and rent, and so forth ad infinitum. [52]