Vom Geist der Gesetze
In the first half of the 18th century, eminent French writers were invited to become members of the Académie Française, but the Academy in practice served largely to glorify the royal family and to keep writers under gentle control, rather to stimulate innovation in literature. Neither Rousseau nor Voltaire were chosen; only one of the great Philosophes of the enlightenment, Montesquieu, was elected a member. His 1748 book "The Spirit of the Laws", proposing a separation of powers between the executive, legislature and courts, had an enormous impact on political thinking outside France, especially in England and the United States.