Let us consider more narrowly the main factors affecting and explaining economic social values. Let us take, first, the simplest case, that of goods and services which minister directly to human wants, goods and services "of the first order." Goods of this sort would be oranges, bread, clothing, jewels. Services of this sort would be the services of the barber, the valet, the physician, the preacher, the teacher, the actor. I abstract, in discussing these values, from the complications that grow out of the friction in retail trade, and the existence of many customary prices, and prices fixed by other than economic values, in the case of teachers, or preachers. I shall concentrate attention upon such things as oranges, bread, clothing, and jewels. The _focus_ of the values of these things, and an essential condition of their existence, is their utility, that is to say, their power to satisfy human wants. Utility as used in economics does not mean usefulness in any moral sense. From the standpoint of the economist, whiskey and opium are as useful as bread, if they satisfy wants equally intense. And the economist is not concerned with the general utility of things considered in their totality. Air is more useful than jewels, but a carat of air is not as useful as a one-carat diamond. Air exists in such abundance that it does not need to be economized. Scarcity with reference to the extent of the wants involved is also essential to economic value. A combination of the ideas of utility and scarcity gives us the simple notion for which the formidable name of "marginal utility" has been devised. The marginal utility of a good to a man is the power the last, or "marginal," unit of the good which the man consumes has to give him satisfaction, or, viewed from the standpoint of the man, is the intensity of his desire[36] for, or of his satisfaction in, the final unit consumed. So far, our account of the value of the orange will seem perfectly acceptable to those accustomed to traditional discussions of the problem in the text-books. The difference is that many text-books stop at this point, leaving the impression that with the definition of marginal utility the whole value problem has been solved. For the social value theory, the conception of marginal utility is barely a starting point. Indeed, it is not even a starting point. We shall have to look both in front of it and _behind it_. Recognizing that marginal utilities to individuals are essential to economic values of consumption goods, we shall have to point out other things which are also essential, and we shall have to explain the factors determining these marginal utilities themselves.