Work, however, is miscellaneous and heterogeneous. There is needed "a pervasive element in the actions, and one that can be measured." This is "personal sacrifice," which is "common to all varieties of labor." An isolated worker, making and using his own products, readily finds an equilibrium point, where utility and sacrifice are equal, and where he stops his day's work (pp. 364-65). If the product of any hour's labor be destroyed (p. 366) he will not suffer the loss of anything more important than the product of the last hour's labor, for he will forego that, and re-create the good with the higher utility. The utility of the last hour's product and the pain of the last hour's labor are equal. Either is his _unit of value_. Of society regarded as a unit the same is true. Take away the articles that the society gains by the labor of a morning hour,--the necessary food, clothing and shelter that it absolutely must have,--and it will divert to making good the loss the work performed at the approach of evening, which would otherwise have produced the final luxuries on its list of goods. (It might be questioned parenthetically here whether _all_ are fed before _any_ begin to enjoy luxuries, or, if not, just what is considered the "socially necessary" amount of food, and whom does social necessity require that we feed before we devote an hour to making luxuries?) Professor Clark finds the final hour of social labor-pain to be a compound, the sum of the final hour's dissatisfactions of all the laborers. This sum is the _ultimate standard of value_. It is in equilibrium with the sum of the utilities of the final hour's products to all the laborers considered as consumers. This is illustrated by a diagram on page 271. But the problem still remains as to the value of particular goods. Granted that the sum of the satisfactions got from the total amount--a vast amount--of the final hour's product is equal to the sum of the pains incurred in producing this giant composite, and granted that the pain incurred by each man in making his part of the composite is equal to the satisfaction gained by him in consuming his part of the composite--_not the same part_!--the problem still remains as to the connection of the marginal utility and the value of the _particular_ goods that make up the composite, with social labor. Professor Clark concedes at once that there is no necessary connection between the utility of the good to him who enjoys it, and the pain of making it to him who makes it. What connection is there than, between the value of the good and social labour? It is at this point, I venture to suggest, that Professor Clark's argument fails. I shall not follow his argument in detail, but shall quote a couple of paragraphs which seem to exhibit the failure (pp. 272-73):--