The displacement (at least to a considerable extent) of the ethical jurisprudence of the seventeenth and eighteenth centuries by positivism reshaped both international law theory and doctrine. In the first place the new doctrine brought a formal separation of international from municipal law, rejecting the earlier view that both were parts of a universal legal system. One result was to nationalize much that had been regarded as the law of nations. Admiralty law, the law merchant, and the host of problems which arise in private litigation because of some contact with a foreign country were all severed from the older Law of Nations and made dependent on the several national laws. Private international law (which Americans call the ``conflict of laws'') was thus segregated from international law proper, or, as it is often called, public international law. States were free to enact, within broad though (perhaps) determinate limits, their own rules as to the application of foreign law by their courts, to vary the law merchant, and to enact legislation with regard to many claims arising on the high seas. The change was not quite so dramatic as it sounds because in fact common norms continued to be invoked by municipal courts and were only gradually changed by legislation, and then largely in marginal situations.