Nicolas Malebranche CO (/mælˈbrɒnʃ/ mal-BRONSH, French: [nikɔla malbʁɑ̃ʃ]; 6 August 1638 – 13 October 1715) was a French Oratorian Catholic priest and rationalist philosopher. In his works, he sought to synthesize the thought of St. Augustine and Descartes, in order to demonstrate the active role of God in every aspect of the world. Malebranche is best known for his doctrines of vision in God, occasionalism and ontologism.