The first and most noticeable theme is religion; this is a key issue in the Enlightenment. The period was marked with growing anti-clerical sentiments, as the proclamations of religious clergy imposed great restrictions on the life of common people. This anti-clerical sentiment was not necessarily an attack on the existence of God, but an objection to organized religion. Similar to other scholars of his time, Voltaire was a deist; he believed in God on the basis of natural, logical conclusions not supernatural inspiration. Using Christianity as a reference point, he discusses the basis of religious intolerance. His writings show us the hypocritical nature of Christians in Europe, and the negative effects of their refusal to accommodate others.