 The theory that ideas are efficacious becomes Malebranche’s mature position, and to mark this development changes are made to later editions of the Search and to other writings. With the advent of this theory, it becomes easier to see the relation between Vision in God and Malebranche’s other main doctrine of Occasionalism, or the view that God is the only genuine cause. Indeed, one can regard Vision in God as a corollary to Occasionalism. As the only true cause, God produces minds, bodies, and the various changes they endure. The mind’s nature is to think and to perceive, and God produces those modifications via ideas, which are the instruments by which he enlightens us.