Who proposed the idea of separation of church and state?

The concept of separation of church and state is most closely associated with Thomas Jefferson. He articulated the principle in a letter to the Danbury Baptist Association in 1802, where he emphasized the need for a "wall of separation between Church & State" to protect religious freedom and prevent government interference in religious matters. This idea was revolutionary at the time and laid the groundwork for the First Amendment in the United States Constitution, which guarantees freedom of religion.

While other thinkers, like John Locke and Voltaire, contributed significantly to discussions about individual rights and religious tolerance, Jefferson was particularly influential in the political implementation of the separation of church and state. Locke spoke about the importance of religious tolerance, advocating for the freedom of individual belief, but he did not explicitly frame his ideas in terms of church and state separation as Jefferson did. Voltaire expressed criticism of organized religion and advocated for civil liberties, while Rousseau focused on the social contract and the relationship between individuals and government rather than explicitly addressing the church-state divide. Thus, Thomas Jefferson is recognized as the key figure who clearly articulated and championed the principle of separating religious institutions from governmental authority.