The needs of men are manifold, and their lives and welfare are not assured if they have at their disposal only the means, however ample, for the satisfaction of but one of these needs. Although the manner, and the degree of completeness, of satisfaction of the needs of men can display an almost unlimited variety, a certain harmony in the satisfaction of their needs is nevertheless, up to a certain point, indispensable for the preservation of their lives and welfare. One man may live in a palace, consume the choicest foods, and dress in the most costly garments. Another may find his resting place in the dark corner of a miserable hut, feed on leftovers, and cover himself with rags. But each of them must try to satisfy his needs for shelter and clothing as well as his need for food. It is clear that even the most complete satisfaction of a single need cannot maintain life and welfare.
In this sense, it is not improper to say that all the goods an economizing individual has at his command are mutually interdependent with respect to their goods-character, since each particular good can achieve the end they all serve, the preservation of life and well-being, not by itself, but only in combination with the other goods.
In an isolated household economy, and even when but little trade exists between men, this joint purpose of the goods necessary for the preservation of human life and welfare is apparent, since all of them are at the disposal of a single economizing individual. The harmony of the needs that the individual households attempt to satisfy is reflected in their property.12 At a higher stage of civilization, and particularly in our highly developed exchange economy, where possession of a substantial quantity of any one economic
good gives command of corresponding quantities of all other goods, the interdependence of goods is seen less clearly in the economy of the individual members of society, but appears much more distinctly if the economic system as a whole is considered.
We see everywhere that not single goods but combinations of goods of different kinds serve the purposes of economizing men. These combinations of goods are at the command of individuals either directly, as is the case in the isolated household economy, or in part directly and in part indirectly, as is the case in our developed exchange economy. Only in their entirety do these goods bring about the effect that we call the satisfaction of our requirements, and in consequence, the assurance of our lives and welfare.
The entire sum of goods at an economizing individual’s command for the satisfaction of his needs, we call his property. His property is not, however, an arbitrarily combined quantity of goods, but a direct reflection of his needs, an integrated whole, no essential part of which can be diminished or increased without affecting realization of the end it serves.
Taken From : PRINCIPLES OF ECONOMICS
