More than any other cause, toleration was the watchword of the Enlightenment. In particular, all of the philospohes agreed that toleration of all religions should be a feature of the state. One of the main reasons for this policy was to attract skilled and wealthy immigrants, as well as to grant people the freedom to practice whatever religion they wanted. However, Denis Diderot stood alone amongst the writers of The Encyclopedie (a book of 28 volumes which was written by nearly all of the French philosophes) by saying that God should be liberated from the shackles of the church. Diderot was vague about his Christianity and once commented, “I am a Christian because it is reasonable to do so.”

Although the other philosophes disagreed with Diderot’s statement, they all strongly agreed that the Church’s power and prestige should be reduced. The philosophes as a whole sought to accomplish the decrease of power of the RC Church by selling its land, taking away its control of education and preventing the persecution of heretics.