Nanwië may refer to the elvish concept of reality or realities. It also could describe the primary World-influence on the Secondary World. Arda was part of its inhabitants Nanwië, to them it was their own reality, but it was not part of the Nanwië of the First World. Instead the First World influences the reality of the Second World which in turn inspires the Poetry and Mythologies of the Primary World, both thus can be interpreted as different realities or different levels or layers of reality, the Secondary World representing the first Worlds sub-creation within a "poetic reality".
Notes[]
Nanwië is a Neo-Quenya term not invented by J.R.R. Tolkien or ever used by him.