This inevitable extension of the sphere of law from the settlement of disputes between individuals to disputes between individual states has been pointed out before, and is fairly obvious. Thus Mougins-Roquefort, a French lawyer, in his book De la Solution Juridique des Conflits Internationaux (1889), observes that in the days of the Roman Empire, when there was only one civilized state, any system of international relationships was impossible, but that as soon as we have a number of states forming units of international society there at once arises the necessity for a system of international relationships, just as some system of social order is necessary to regulate the relations of any community of individuals.