Read the passage carefully and answer the questions that follow:

The acceptance of international law as law poses the problem of explaining its binding force, and this in turn raises questions as to the authority of all law. Some writers have sought to demonstrate the binding character of international law from its derivation from natural law. But we have seen that natural law is nothing more than morality and that the existence of moral rules is no guarantee of the existence of corresponding legal rules. Such an argument shows at most that the rules of international law are morally binding, not that they are legally binding. Moreover, many legal rules are morally indifferent; morality may demand the existence of some rule without specifying what that rule should be. Such is the case in municipal law with regard to the formalities required for wills, contracts and conveyances; and in international law with some of the rules regarding title to territory and the limits of jurisdiction. The binding force of such rules can hardly be attributed to any moral characteristic.