The arcane tradition, also known as the orthodox scheme, is a mainstream metaphysical philosophy that models the planes of the multiverse as a series of nested spheres.1
The arcane tradition organizes the planes into discrete groups in relation to one another. In the Inner Sphere, the Positive and Negative energy planes create and destroy life in opposition to one another, the Material Plane of our reality spreads across an infinite dimension, the adjacent Elemental Planes provide the fundamental materials of the multiverse, and the Ethereal Plane permeates the space in between. The Astral Plane surrounds the Inner Sphere and connects it to the Outer Sphere planes, the destination of all mortal souls.1
- ↑ 1.0 1.1 Jason Bulmahn et al. (2015). Occult Adventures, p. 238. Paizo Inc.