Common policies , which are the essence of multinational integration, are based on prevalent legislation. About 160 AD, about 600 years after the establishment of the Twelve Tables, a jurist named Gaius wrote about Roman laws. The laws of the Twelve Tables had been under no circumstances repealed but some fell into disuse as the centuries passed. Some authors think about civil law to have served as the foundation for socialist law used in communist countries, which in this view would fundamentally be civil law with the addition of Marxist-Leninist ideas. Most nations these days stick to one of two important legal traditions: frequent law or civil law.