This study is an attempt to analyse the stance which the positivist philosophy takes on religion in the context of modern philosophy. The adopted approach is basically a critique of Ernest Renan's criticism of Islam's relation to philosophy and science. Discussing his views expounded in his famous lecture will be extended to the wider circle of the modern Western philosophy in order to move beyond the confines of the older static circle. This will include comparisons with the stand taken by other positivist philosophers on religion, such as Saint-Simon and Auguste Comte among other modern philosophers who generally criticised religion (Hume, Voltaire, Nietzsche, etc.). Will be given as well is a critical analysis of Renan's views in relation to the French thought transformation of his time, in particular, and Orientalist views in general. The framework is the positivist trend and its conflict with the religious trend at the age of ideology.