During the Middle Ages, when foreigners were too frequently subjected to unjust treatment, treaties were, no doubt, necessary for their protection. For instance, at one time, all foreigners residing in England were held liable for the debts and even for the crimes of each other. Shipwrecks, though attended with less of the barbarity of earlier times, were regarded in most countries as fortunate opportunities for plunder; while tolls and local charges of the most arbitrary description were levied on aliens by states, princes, corporations, and the lords of manors. There were also many other matters scarcely less oppressive and unjust which could only be redressed by negotiations. [Sidenote: but inadequate for the regulation of commercial intercourse, and liable to unfair diplomacy.] Under such circumstances it was necessary for commercial States to secure, by treaties, that protection and security for the person and property of their subjects abroad against the injustice they were liable to, and which they could not obtain from the laws of the countries where they might happen to be. Treaties were also required for the regulation of neutral commerce during war, and for defining clearly what goods could not be carried by neutrals for the belligerents. For all such purposes treaties were, of course, essential; but, when they came to be used, with the further object of teaching different nations how to conduct their own business, a practice arose which, however useful at the time in assisting a change of system, could not long endure. Regulations as to the duties chargeable on certain articles, or for the privileges of certain ships, according as they were built by, or belonged to, particular countries, inducing constant misrepresentation and tending to create grave differences between nations, were soon found to be neither the best nor the wisest means for producing economic or friendly commerce. Moreover, the whole system of treaties so constructed was attended with a mode of bargaining, in which the clever diplomatist might frequently gain unfair advantages for the people he represented. Such a course of action was so obviously undignified in the conduct of national affairs, that all merchants of high standing in different countries at length protested against it. Statesmen, also, began to discover that, as a rule, it was better for commerce to flow on with no interference from treaties or other legislation—that, as a matter of fact, it prospers best unaided; and, further, that such a state of things, while unsatisfactory so far as the intercourse between nations is concerned, was also discreditable, alike to the nations entertaining such propositions, and to the ministers or officers by whom they were proposed.