Nations adopt constitutions for the same reason that the ancient Mesopotamian lawgiver Hammurabi codified the laws of Babylon: to establish a supreme law of the land. Constitutions state the fundamental laws of society and are not meant to be easily revised.They are yardstick by witch activities of the government or the people are measured.A legislature can pass a law one year and repeal it the next, but amending the constitution is made deliberately much harder.In Sweden,constitutional amendments must be passed by two successive legislature with a general election in between.