The Age of Enlightenment was the intellectual and philosophical movement that occurred in Europe in the 17th and the 18th centuries. The Enlightenment featured a range of social ideas centered on the value of knowledge learned by way of rationalism and of empiricism and political ideals such as natural law, liberty, and progress, toleration and fraternity, constitutional government and the formal separation of church and state.

The separation of church and state is a philosophical and jurisprudential concept for defining political distance in the relationship between religious organizations and the state. Conceptually, the term refers to the creation of a secular state and to disestablishment, the changing of an existing, formal relationship between the church and the state. The concept originated among early Baptists in America. In 1644, Roger Williams, a puritan minister and founder of the state of Rhode Island and The First Baptist Church in America, was the first public official to call for "a wall or hedge of separation" between "the wilderness of the world" and "the garden of the church." Although the concept is older, the exact phrase "separation of church and state" is derived from "wall of separation between Church & State," a term coined by Thomas Jefferson in his 1802 letter to members of the Danbury Baptist association in the state of Connecticut. The concept was promoted by Enlightenment philosophers such as John Locke.