A discussion of the separation of church and state in the United States is concerned with the meaning of 16 words -- two clauses -- in the First Amendment to the U.S. Constitution. The First Amendment states that "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof..." The first part of this statement is called the Establishment Clause, and the second is called the Free Exercise Clause. Before we can discuss what these clauses mean today, it is important to consider their history.
The two philosophers who had the greatest impact on the people who wrote the U.S. Constitution were John Locke and Baron de Montesquieu. Both had written extensively in support of a separation between religion and the state, and their ideas and writings were frequently used to support various positions in the debates about what the Constitution should contain.
John Locke was born in England, the son of an attorney, in 1632. Before his death in 1704, he had witnessed the beheading of an English king, Charles I, and a series of civil wars and revolutions in England that changed an absolute monarchy into a democracy. During the English Civil War, while young John attended Puritan schools (including Christ Church College at Oxford University), his father fought for democracy on the side of Oliver Cromwell.
After Cromwell's victory, John Locke witnessed the inability of the three major Protestant sects in England (the Puritans, Anglicans, and Presbyterians)