This political scientist and author of two treatises on civil government believed that no government can exist without the consent of the governed and that the primary purpose of the state was to protect the rights of the citizen: hobbes locke blackstone montesquieu

Locke

English philosopher John Locke published his Two Treatises on Civil Government in 1689.  The first treatise was a debunking of the prevailing idea of "divine right monarchy."  The second treatise (which remains more famous today) set forth Locke's views on the social contract, that the government gets its authority from the people who consent to be governed.  Much of American government ideas came from the philosophy of John Locke.