ABSTRACT
Economists quite generally agree that the commodity selected to serve as money should have the following qualities: value, durability, portability, homogeneity, divisibility, cognizability, and stability of value. These texts exemplify the importance attached by economists to such physical characters as durability, portability or mobility, homogeneity and gradability, divisibility and cognizibility. And these characters may be almost indefinitely analysed or combined to form further physical characters of great economic significance. Durability, portability, gradability, divisibility, are admittedly important characters in economic life and economic theory; and they are characters that can be measured objectively along a scale of degrees and of which statistics can eminently be formed. In the course of their arguments economists make the psychological assumption of an economic man who "substitutes", "anticipates", "selects", in rational ways. The psychological roots of economic behaviour help in interpreting statistically established facts and relations, and nowhere is this psycho-physiological interpretation more important than in the economics of production.
