British political theorist and philosopher John Locke is known for his belief in a system of limited government in which natural rights are the basis for a social contract existing between the governed and their government. Because of the inherently unstable state of nature, Locke believed that people relinquish certain rights in exchange for an agreement with their government that provides protection from harm and security for their property and possessions. Locke also advocated a separation of powers in government and wrote powerful arguments in defense of religious tolerance.
One of Locke's most important claims was his argument that God did not create man to be naturally ruled by a monarch. His concept of a social contract defines a legitimate form of government as one in which people in the unstable state of nature conditionally transfer some of their natural rights to government in exchange for that ruling body's guarantee of stability, safety and promotion of the public good. When a government fails to do so, however, the people have the natural right to resist and replace that government. In this way, Locke advocates the right of revolution that became a main premise of the American Declaration of Independence. The concept of a separate legislative and executive branch in the construction of a government was also taken from Locke, along with the belief that the governed should have representatives with enough power to block any attempts at unjust taxation or attacks on individual liberty.