Thomas Hobbes (1588–1679) was an English philosopher and a major representative of social contract theory. He is best known for Leviathan, a work that systematically discusses the origins of the state, the power of the sovereign, and the conditions that sustain political order, and that has had a lasting influence on the history of Western political thought. Hobbes examined political questions within a framework of human nature and order, arguing rigorously and defining concepts clearly, often proceeding step by step in a way that gives his writing a marked theoretical character. He used the idea of contract to explain the formation of political community, an approach later discussed and answered by thinkers of different persuasions. One of his works is included in this catalogue under the category of motivational growth; public information on the details of his life is limited, so readers may begin with the work itself and appreciate its argumentative style and intellectual concerns.