Nicolas Malebranche (1638-1715) is a french philosopher and theologian. He is the principal developer of Cartesianism, i.e. the philosophy of Descartes.
In his De la Recherche de la Vérité (1674), Malebranche advanced a theory of the relation between mind and body known as occasionalism. As to the causal interaction between physical objects, Malebranche asserts that when two bodies collide, the motion of one has no power to affect the motion of the other, since there is no necessary connection between the two (contrary to Hume philosophy).
We see all in God
A corrolary of Malebranche’s view of causation is his famous thesis that “we see all things in God” : since an idea cannot be produced by external objects “all our ideas are in the efficacious substance of the divinity“. This curious doctrine was taken by the philosopher to explain our alleged knowledge of eternal and necessary thruths.