 Madison explicitly credited Martin Luther as the theorist who "led the way" in providing the proper distinction between the civil and the ecclesiastical spheres with his doctrine of the two kingdoms.Controversy rages in the United States between those who wish to restrict government involvement with religious institutions and remove religious references from government institutions and property, and those who wish to loosen such prohibitions.Advocates for stronger separation of church and state, such as already exists in France with the practice of laïcité, emphasize the plurality of faiths and non-faiths in the country, and what they see as broad guarantees of the federal Constitution.