About Nicolas Malebranche
Nicolas Malebranche (French: [nikɔlɑ malbrɑ̃ʃ]; 6 August 1638 – 13 October 1715) was a French Oratorian 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 and Occasionalism. Known by many as "The Occasional Philosopher," a term coined by David Hume.
Philosophical career 
In 1674-75, Malebranche published the two volumes of his first and most extensive philosophical work. Entitled Concerning the Search after Truth. In which is treated the nature of the human mind and the use that must be made of it to avoid error in the sciences, the book laid the foundation for Malebranche’s philosophical reputation and ideas. It dealt with the causes of human error and on how to avoid such mistakes. Most importantly, in the third book, which discussed pure understanding, he defended a claim that the ideas through which we perceive objects exist in God. Malebranche's first critic was the Abbé Simon Foucher, who attacked the Search even before its second volume had been published. Malebranche replied in a short preface added to that second volume, and then, in the 1678 third edition, he added 50% to the already considerable size of the book with a sequence of (eventually) seventeen Elucidations. These responded to further criticisms, but they also expanded on the original arguments, and developed them in new ways. In the Tenth Elucidation, for instance, Malebranche introduced his theory of "intelligible extension", a single, archetypal idea of extension into which the ideas of all particular kinds of bodies could be jointly resolved. In others, Malebranche placed a greater emphasis than he had previously done on his occasionalist account of causation, and particularly on his contention that God acted for the most part through "general volitions" and only rarely, as in the case of miracles, through "particular volitions". Malebranche expanded on this last point in 1680 when he published Treatise on Nature and Grace. Here, he made it explicit that the generality of the laws whereby God regulated His behaviour extended not only to His activity in the natural world but also applied to His gift of grace to human beings. The book was attacked by fellow Cartesian philosopher, Antoine Arnauld, and, although Arnauld's initial concerns were theological ones, the bitter dispute which ensued very quickly branched out into most other areas of their respective systems. Over the next few years, the two men wrote enough polemics against one other to fill four volumes of Malebranche's collected works and three of Arnauld's. Arnauld's supporters managed to persuade the Roman Catholic Church to place Nature and Grace on its Index of Prohibited Books in 1690, and it was followed there by the Search nineteen years later. (Ironically, the Index already contained several works by the Jansenist Arnauld himself). Other critics with whom Malebranche entered into significant discussion include another fellow Cartesian, Pierre Sylvain Regis, as well as Dortous de Mairan. De Mairan was sympathetic to the views of Baruch Spinoza, and felt that he had found similar views in his reading of Malebranche: Malebranche assiduously resisted such an association.