A World for Us aims to refute physical realism and establish in its place a form of idealism. Physical realism, in the sense in which John Foster understands it, takes the physical world to be something whose existence is both logically independent of the human mind and metaphysically fundamental. Foster identifies a number of problems for this realist view, but his main objection is that it does not accord the world the requisite empirical immanence. The form of idealism that he tries to establish in its place rejects the realist view in both its aspects. It takes the world to be something whose existence is ultimately constituted by facts about human sensory experience, or by some richer complex of non-physical facts in which such experiential facts centrally feature. Foster calls this phenomenalistic idealism. He tries to establish a specific version of such phenomenalistic idealism, in which the experiential facts that centrally feature in the constitutive creation of the world are ones that concern the organization of human sensory experience.
The basic idea of this version is that, in the context of certain other constitutively relevant factors, this sensory organization creates the physical world by disposing things to appear systematically world-wise at the human empirical viewpoint. Chief among these other relevant factors is the role of God as the one who is responsible for the sensory organization and ordains the system of appearance it yields. It is this that gives the idealistically created world its objectivity and allows it to qualify as a real world.