Who was a 17th century English philosopher whose book Leviathan 1651 helped to clarify both the social contract theory of government?

Thomas Hobbes was the 17th-century English philosopher who wrote "Leviathan" in 1651. In this book, he presented his social contract theory of government, which outlined the need for a powerful central authority to maintain order and prevent chaos in society. Hobbes believed that individuals willingly give up some of their freedoms in exchange for security and a stable society.