Navigare necesse est. lex fundamentalis semper reformanda

The year 2017 saw the celebration of the 25th anniversary of the adoption of the Constitution of Lithuania and the 20th anniversary of the adoption of the Constitution of the Republic of Poland. This article presents the common constitutional heritage of these two countries primary as commonwealth est. in 1385 year and next as Polish–Lithuanian Union from 1569 to the end of the 18th century when we lost our independence. It sets out the main assumptions of the theory of the norms of basic law. The author also sums up the importance of legal culture and the social acceptance of the legal order set by a constitution as a fundament of democratic states. The author presents his reflections using metaphors from nautical terminology.