primary world n.

It seems fairly clear that Lang was using belief in its ordinary sense: belief that a thing exists or can happen in the real (primary) world.

I propose, therefore, to arrogate to myself the powers of Humpty-Dumpty, and to use Fantasy for this purpose: in a sense, that is, which combines with its older and higher use as an equivalent of Imagination the derived notions of 'unreality' (that is, of unlikeness to the Primary World), of freedom from the domination of observed 'fact', in short of the fantastic.

The fantastic assumption of sustained and consistent impossibility cannot long remain in a primary world whose physical laws and accompanying mentality must dismiss nonconforming phenomena as being either rationally explicable or incomprehensible.

The writer, as an omnipotent secondary creator, need only state that the world within the text mirrors the primary world to establish the fact to his own satisfaction.