Malebranche studied philosophy and theology at the Collège de la Marche from 1654 to 1656 and graduated Master of Arts. P André writes in  that he found theology:-
... neither great nor true, full of vain subtleties, perpetual equivocation, lacking in taste and Christian spirit.Malebranche went to the Sorbonne in Paris until 1659, again intending to make theology his life's work but he found it no more to his liking than he had before. He considered it :-
... only a confused mass of human opinions, frivolous discussions and hair-splitting subtleties, without any order or principle or rational interconnection.Refusing to accept a canonry at Notre Dame, he joined the Congregation of the Oratory in 1660. The Congregation of the Oratory of Jesus and Mary Immaculate, also called the Bérulliens, was founded by Pierre de Bérulle in 1611. Its chief aim was, and still is, training candidates for the priesthood. De Bérulle was a friend of Descartes and by the time Malebranche studied at the Oratory its teaching were strongly based on Descartes' philosophy. In 1664 Malebranche was ordained a priest having studied ecclesiastical history, Hebrew and Biblical criticism.
Malebranche read Descartes' Traité de l'homme and this turned him towards a study of mathematics and physics. In  his reaction to Descartes' book is recounted:-
The joy of becoming acquainted with so large a number of discoveries caused him such palpitations of the heart that he was obliged to stop reading in order to recover his breath.Malebranche himself said that Descartes had:-
... in thirty years discovered more truths than all the other philosophers put together.Malebranche was also influenced by Leibniz who visited Paris in 1672. The two had many meetings when they discussed ideas both of philosophy and of mathematics and, in particular, Leibniz conveyed many of his ideas about his new calculus to Malebranche.
Malebranche became professor of mathematics at the Congregation of the Oratory from 1674. He had a large influence on the development of mathematics and science, principally through the group which he built up in Paris which was seen as the leading one in France. Mathematicians such as Varignon, de L'Hôpital, Guisnée and Reyneau all became part of this circle at the Oratory.
Although Malebranche made no outstanding mathematical discoveries, he is of major importance in the development of mathematics since through him the work of Leibniz and Descartes in mathematics was spread and developed. One of Malebranche's direct contributions to mathematics was his editorial role in the publication of de L'Hôpital's Analyse des infiniment petits pour l'intelligence des lignes courbes. Malebranche also had a strong influence through his teaching, in particular he taught mathematics and physics to Privat de Molières and Reyneau. Others were not so much his disciples as his opponents, for example he was in dispute with Arnauld for many years.
Malebranche is a major philosopher and follower of Descartes. His metaphysics is his belief that we see all things in God. Human knowledge of the world is only possible through a relation between man and God. He developed Descartes' ideas to bring them more in line with standard Roman Catholic orthodox belief.
At first Malebranche's ideas of the physical world followed closely those of Descartes and were based on a belief in a rational geometrical world. He based his laws of motion on the abstract laws of collisions between idealised solid objects. However Leibniz tried, with some success, to persuade Malebranche that the laws of motion were not entirely mathematical laws but were the consequence of God's creation.
When it came to an understanding of force, Malebranche found great difficulties with the ideas of his fellow scientists. He wrote:-
It seems to me that people make very great errors and even very dangerous ones regarding force which gives movement and which transports bodies.How did Malebranche explain force? He did not believe in Descartes' idea of a "clockwork universe' which God set in motion and then it ran itself, only determined by completely general laws of mathematics. Malebranche needed to have a more active role for God in his universe and he did this through his concept of force. He basically believed that if two spheres collided then there was no force which changed the direction of their motion. Rather he saw the collision as an occasion for God to act and since a perfect God would act in the simplest way then the result would always result in the same change in motion.
Malebranche's most important work is the three volumes of De la recherche de la vérité (1674-75). The work received much acclaim from many and was translated into many languages. Criticism of his work, in particular by Arnauld, led to Malebranche's publication of Traité de la nature et de la grâce (1680), which was banned by the Roman Catholic Church ten years later. Another important work is Entretiens sur la métaphysique et sur la religion (1688) in which Malebranche sets out in the clearest way his metaphysics and philosophy.
Malebranche's other work includes research into the nature of light and colour, studies in the infinitesimal calculus and work on vision. This mathematical and scientific work was published in Réflexions sur la lumière, les couleurs et la génération du feu in 1699. He was elected to the Académie des Sciences in the same year of 1699 mainly as a result of his work Traité des lois de la communication du mouvement.
What was the opinion of contemporary and later writers on Malebranche and his ideas? Fontenelle considered him a great mathematician and physicist and also a great writer:-
His diction is pure and chaste, and has all the dignity which the subject requires and all the grace of which it admits.D'Alembert also praises his writing but not his philosophy:-
I think that he is in all respects very inferior to Bayle and Gassendi as a philosopher; it even seems to me that he was less a great philosopher than an excellent writer on philosophy ... I see him as a good demolisher but a bad architect.All d'Alembert can find in the way of praise of Malebranche's De la recherche de la vérité is to say it contained:-
... a few useful truths concealed as it were stifled beneath a heap of systems which have long since been forgotten.However d'Alembert finds that Malebranche writes in:-
... the most suitable language for philosophy, the only one worthy of it, methodical without dryness, thoroughly developed but without verbiage, interesting and sensible without false warmth, great without effort, and noble without turgidity.Voltaire echoed the same thoughts when he compared Locke and Malebranche saying:-
A single page of Locke contains more truths than all the volumes of Malebranche; but a single line of Malebranche reveals more subtlety, imagination, finesse, and genius, perhaps, than all of Locke's enormous book.Malebranche was to have a strong influence on many who visited Paris while he and his disciples exerted a strong influence there. One who was strongly influenced was Berkeley who visited Paris in 1713 and met with Malebranche.
Malebranche was taken ill in 1715 while staying at the house of a friend at Villeneuve- Saint- Georges. He was taken back to the Oratory in Paris and died four months later after great suffering. Fontenelle writes that his illness:-
... adapted itself to his philosophy. The body, which he so much despised, was reduced to nothing; but like the mind, accustomed to supremacy, continued sane and sound. He remained throughout a calm spectator of his own long death, the last moment of which was such that it was believed he was merely resting.
Article by: J J O'Connor and E F Robertson