The Modern Theory of the World refers to the idea that, outside of Mundis, there exists four other "worlds": Mnemosyne, the World of Memory; Oneiris, the World of Dream; Panton, the Perfect World; and Niil, a void between the other four worlds.

The concept of this was created in Kendall's creation myth, and huge support was gathered for it after Morqa's initial research on the matter.