English philosopher Thomas Hobbes (1588–1679), one of the founders of the social contract theory, believed that in order to gain security, people must cede part of their natural rights to the mighty Leviathan of the state. The treatise "Leviathan", written in the context of the English Revolution, with an obvious conflict between the legislative and executive powers (king versus parliament), became one of the most important studies on the theory of power and had a tremendous influence on the development of culture, philosophy and the political structure of modern society. The book also includes Hobbes' works "Human Nature" (1650) and "On Liberty and Necessity" (1654).