Natural Law and Natural Rights
Locke's political theory (set forth in 1690 in his Two Treatises of Government) defended the doctrine of human liberty and human rights against absolutism. Men are born free and equal, since in a state of nature only natural laws obtained and they knew of legal standards. When a society developed, the members entered into a social contract in which they granted to selected officials certain powers set forth in their constitution. Government is therefore collective by nature; it is founded on and hence always subject to the mutual consent and joint decisions of the citizens.
In Two Treatises he argues against the divine right of kings and maintains that all men are free and equal in the state of nature and possess certain natural rights. Locke's political doctrines were incorporated into the American Constitution and into the constitution in France in 1871. It was Thomas Jefferson who said of Locke's Second Treatise, “It is perfect as far as it goes,” meaning that it was a blueprint for a working constitution.
During his lifetime Locke published most of his political writings anonymously, preferring to keep them separate from the Essay, which he regarded as his most important work.
What is the difference between Hobbes's and Locke's social contract?
Thomas Hobbes believed that a social contract existed between the ruler and the masses in an effort, by any means necessary, to keep civilization from reverting to its natural state, which Hobbes believed was savage anarchy. Locke believed that the contract is there for the greater good of society and to uphold the inherent rights of the individuals.