We are all born with an imperious material want, which must be satisfied under pain of death, I mean that of breathing. On the other hand, we all exist in a medium which, in general, supplies that want without the intervention of any effort on our part. Atmospheric air, then, has utility without having ‹value›. It has no Value, because, requiring no Effort, it gives rise to no service. To render a service to any one is to save him trouble; and where it is not necessary to take pains in order to realize a satisfaction, no trouble can be saved. But if a man descend to the bottom of a river in a diving-bell, a foreign substance is interposed between the air and his lungs, and, in order to re-establish the communication, a pump must be employed. Here there is an effort to make, pains to take, and the man below desires the exertion, for it is a matter of life or death, and he cannot possibly secure to himself a greater ‹service›. Instead of making this effort himself, he calls on me to make it for him, and, in order to induce me to do so, he undertakes in turn to make an exertion from which I may reap satisfaction. We discuss the matter, and come to an agreement. Now, what do we discover here? two wants, two satisfactions, which are not inconsistent with each other; two efforts, which are the subject of a voluntary transaction; two ‹services›, which are exchanged,—and ‹value› makes its appearance. Now, we are told that utility is the foundation of value; and as utility is inherent in the air, we are led to think that it is the same in regard to value. There is here an evident confusion of ideas. The air, from its nature, has physical properties in harmony with one of our physical organs, the lungs. The portion which I draw from the atmosphere in order to fill the diving-bell does not change its nature—it is still oxygen and azote. No new physical quality is combined with it, no reacting power brings out of it a new element called ‹value›. ‹That› springs exclusively from the service rendered. [p138] If, in laying down the general principle, that Utility is the foundation of Value, you mean that the Service has value because it is useful to him who receives it and pays for it, I allow the truth of what you say. It is a truism implied in the very word ‹service›. But we must not confound the utility of the air with the utility of the service. They are two utilities distinct from each other, different in nature, different in kind, which bear no proportion to one another, and have no necessary relation. There are circumstances in which, with very slight exertion, by rendering a very small service, or saving very little trouble, I may bring within the reach of another an article of very great intrinsic ‹utility›.