3. There is a place in his book where Mill wavers in the decision to include profits in cost of production. The probable explanation of his hesitancy is of considerable interest, for it suggests the internal weakness of the theory that cost in any form is the essence of value. His doubt arises in connection with the familiar case of the relative values of a cask of wine and a piece of cloth, originally costing the same amount of labor in their production. The difficulty arises from the fact that the wine alone continues to increase in value through mere lapse of time: “The wine and the cloth were made by the same original outlay. Here then is a case in which the natural values, relatively to one another, of two commodities, do not conform to their cost of production alone, but to their cost of production plus something else.” In this sentence Mill excludes “profits” from cost. But he continues: “Unless, indeed, for the sake of generality in the expression, we include the profit which the wine merchant _foregoes_ during the five years in the cost of production of the wine.”[162] The word “foregoes” (not italicized by Mill) is uncalled for. The wine merchant does not get profits he foregoes elsewhere, but the profits he makes from the added value of the wine. They might be greater or less than the profits foregone elsewhere. The forces tending to make them equal to those elsewhere relinquished are precisely the same in this case as in any other. If they are greater, more five-year-old wine will be brought to the market and its price will fall, and if they are less the reverse will happen. What is the difference between this case and the case of an ordinary industrial product that Mill should falter so? Does capital (using the term in the sense defined by J. B. Clark), the fund of wealth employed in production, play different rôles in the two cases? Not in the least. Suppose a fund of capital is embodied in a certain quantity of raw material for a certain length of time until the same becomes final product. The final product, besides covering all other expenses, affords a sum of value equal to the capital invested in materials plus the interest on it. The difficulty felt in the case of the wine was undoubtedly that no tools, machinery, or labor were employed upon it during the time of its improvement in value. The changes working within it effected its increase in value merely by augmenting its utility to users of wine. The increase of value, secondly, affords a “profit” or interest. This profit may strike the mind as a surplus over cost to the entrepreneur, but the relation of this interest to the value of the final product is precisely the same as in any common case of manufacture. Interest as a cost can influence the value of the product only by influencing its supply. To discover the essential nature of value, we must lay bare the causes which determine what the value of a given supply is, independently of its cost.