The Age of Enlightenment is the era in Western philosophy, scientific and cultural life, positioned upon the 18th century, in which reason was promoted as the primary source for validity and influence. The "Enlightenment" was not a single movement or school of thought, but a set of ideas than it was a set of values. At its core was a critical questioning of traditional institutions, customs, and morals, and a strong belief in rationality and science. Developing simultaneously in France, Great Britain, Germany, the Netherlands, Italy, Spain, Portugal and the American colonies, the movement was maintained by Atlantic Revolutions, especially the success of the American Revolution, when breaking free of the British Empire. The authors of the American Declaration of Independence, the United States Bill of Rights, the French Declaration of the Rights of Man and of the Citizen, and the Polish-Lithuanian Constitution of May 3, 1791, were motivated by Enlightenment principles.