Nicolas Malebranche
French philosopher and theologian (1638–1715), born in Paris with a physical deformity that weakened his health for life, ordained a priest of the Oratory of Jesus in 1664, and who experienced, according to tradition, a genuine intellectual revelation upon chancing to read Descartes's Treatise of Man, a discovery that launched him into passionate philosophical devotion within the Cartesian tradition, which he developed originally and radically to limits Descartes himself would probably not have accepted. His masterwork, The Search After Truth (1674–1675), develops his most famous doctrine, 'occasionalism', according to which, since mind and body are radically heterogeneous substances (as Descartes had established), no finite entity — neither body nor mind — can exert genuine efficient causation on any other; the only true cause of any event is God himself, who acts directly on every 'occasion' on which a causal relation between creatures appears to occur, so that when, for example, the will decides to move an arm, that will is merely the occasion God seizes upon to produce the bodily movement directly. From this radically theocentric metaphysics, Malebranche derives his no less famous theory of the 'vision in God': since pure, universal ideas cannot be found in the finite mind or in matter, humans perceive and know the world not directly but through the eternal ideas existing in the divine understanding itself, to which the human mind has partial access through divine illumination — a thesis that embroiled him in a long, celebrated philosophical controversy with Antoine Arnauld over the nature of ideas and perception. Malebranche also developed an original theodicy reconciling the existence of evil with divine goodness, arguing that God, in his perfect wisdom, always acts through simple, uniform general laws rather than constant particular miracles, so that certain particular evils are the inevitable but rationally justified price of the wisest and simplest possible general order. His synthesis of Cartesianism, Augustinianism and Catholic theology exerted notable influence on Berkeley, Hume and Leibniz, even though his work was placed on the Catholic Church's Index of Forbidden Books shortly after his death.