John Locke was an Oxford academic and a medical researcher whose association with the first Earl of Shaftesbury led him to become a very successful government official. He collected information about the trade within the colonies, he was an economic writer, a political activist, and most importantly, a revolutionary whose cause ultimately triumphed during the Glorious Revolution of 1688, which resulted in the deposition of James II and accession of William III and Mary II to the English throne.
Most of Locke's work is characterized by opposition of authoritarianism which is an emphasis on the authority of state in a republic or union. It is a political system controlled by non-elected rulers who usually permit some degree of individual freedom. This opposition is based on the level of the person and the institution of church and government.
He emphasized the search for reason through truth rather than simply accepting the authoritative opinion or be subject to superstition. It was important to remember the difference between the legitimate from the illegitimate functions of the institutions and to make the distinction for the uses of force against these institutions.
To put it simply, the idea was to encourage human flourishing for the individual and society in respect to its material and spiritual welfare. This, in turn, amounts to following natural law and the fulfillment of the divine purpose for humanity.
When Locke wrote the essay concerning Human Understanding, it revolutionized the limits of human understanding in respect to God, the self, natural kinds and artifacts, as well as a variety of different kinds of ideas. Therefore, this views tells us what we can understand and one cannot.
Locke also wrote a variety of important political, religious and educational works including the Two Treaties of Government, the Letters Concerning Toleration, The Reasonableness of Christianity and Some Thoughts Concerning Education.
The Two Treaties of Government attack patriarchalism in the form of sentence-by-sentence refutation of Robert Filmer's Patriarcha and it also outlines a theory of civil society based on natural rights and contract theory.
Check out Discovery Channels presentation of John Locke and His Philosophy