The international implications of the money phenomenon were to some extent perceived as early as the time of some of the scholastics who found in the universal use of money an instance of the operation of the Law of Nations (jus gentium). The latter term, it is true, was employed by the scholastics rather ambiguously, covering also rules observed by all or most nations in domestic relations. A later writer of the seventeenth century, Samuel Rachel, went further. In his Dissertations on the Laws of Nature and of Nations (1676) he advances the idea that the international circulation of many coins—he mentions especially the Turkish Ducats—proves the existence of a Law of Nations in the modern sense of a law governing the relations among independent states.

Politics require principles. When it is a question on the one hand of acquiring a position, and on the other hand of defending it, the opposed interests seek bases upon which they can rest. The sovereignties feel the necessity of invoking the authority of a principle which seems to draw its force from considerations superior to those that can inspire the political pretensions of a particular state. An appeal is made to a common interest the supposed existence of which is taken for granted—namely, that of maintaining the peace and good relations among the states—and it is presented in a definite formula, the principle of equilibrium.