This section returns to a key legal dimension of the constitution. The constitution is not only law, it is supreme law. This means that no law or policy that is inconsistent with the constitution is valid—and the social contract is safeguarded, both in its symbolic and in its substantive elements. The constitution binds all the people and their institutions, not only state organs. Experience has shown that the purposes and dictates of the constitution are not easily achieved. It is difficult to establish the rule of law under which state power is exercised for the purposes for which it is granted or in accordance with procedures prescribed by the constitution. Because this is not easy, especially in societies where other sources of power (such as customs or religion) are often inconsistent with those of the constitution, constitution-makers have to pay special attention to rules and procedures for implementation and enforcement.