the sum of its uses to him. The value of the piano measures the total amount of satisfaction _conditioned_ upon its possession. When goods are used in stocks any one unit _conditions_ only the satisfaction had from the last unit. Thus only does _marginal_ utility—the actual total utility of the marginal increment—determine value. It is quite futile to attempt to distinguish between the different uses of a unit commodity and arrange these in a descending scale and choose a marginal use. When the unit is taken away all these uses would be sacrificed. Professor Dietzel, an undiscerning critic and imitator combined of the Austrians, has stated that it is the “highest use,” the use on the upper margin, which determines the value of a unit commodity.[225] A second method of discovering a marginal utility for a piano is to conceive of the utility of a piano to that possessor who has just been able to afford the price as the marginal utility of pianos. All men pay the same price for a given grade of piano, but the rich men have much higher price equivalents than the poor. If the supply of pianos to be sold in a given social market be increased, the price will fall. This fall is interpreted as being caused by a decline in the “marginal utility” of pianos. There is no justification for this logic in the utility theory. It is not possible to compare the satisfactions had from pianos by different persons. It is not possible to imagine the pianos in society arranged in a series, the pianos of highest utility being those held by the persons who could afford to pay most and so on. The price of a piano depends upon the _marginal price equivalent_ of a piano, but neither the exchange value nor the esteem value of a piano depends upon _marginal_ utility. To conclude, all goods derive their exchange values from the esteem values placed upon them by consumers. The exchange value of a good in money is determined in a marginal manner by the price equivalents set upon the good by the consumers. Since the extent of a consumer’s money income helps determine the price equivalents placed upon all articles by him, it is impossible to show that these price equivalents depend solely upon esteem values. But it is still proper to say that the esteem value of a good is the sole source of its exchange value. A consumer will assign no price equivalent to a good unless it possess esteem value, and when he does assign a price equivalent, it will be precisely in proportion to the esteem value of the good as compared with other goods which he values.