primordial substance

The materia prima should not be understood merely as a primordial condition of the substance but also as an inner experience of the alchemist. The reduction of matter to its original condition of absolute indifferentiation, corresponds, on the plane of inner experience, to the regression to the pre-natal, embryonic state. The theme of rejuvenation and longevity by means of the regresses ad uterum is a leitmotif of Taoism. The most usual method is “embryonic respiration” (t'ai-si). But the alchemist also achieves this state by the smelting of various ingredients in his furnace.
—  Mircea Eliade, The Forge and the Crucible: The Origins and Structures of Alchemy

A lot of folks are fairly negative about the changes that Dungeons & Dragons 4th Edition made to the D&D cosmology, but for my part, I’m just impressed that it managed to come up with a cosmology that not only has clerics make any damn sense, but actually justifies the arcane/divine magic split.

In a nutshell, 4E’s cosmology is dominated by two realms: the Elemental, and the Astral. The Elemental is the realm of substance and expression, while the Astral is the realm of conception and purpose.

The exemplars of the Elemental realm are the Primordials, beings of infinite substance and unstoppable action. However, as they lack any Astral component, they have no will and their actions have no purpose.

The exemplars of the Astral realm are the Gods, beings of perfect conception and infinite will. However, as they lack any Elemental component, they have no substance and no capacity to act.

Mortals, partaking of the Elemental and Astral realms in equal measure, are able to form symbiotic relationships with both.

When a mortal exercises her will to give purpose and direction to Elemental substance, that’s where arcane magic comes from.

Similarly, when a mortal allows the perfected will of the Astral realm to find substance and expression through her, that’s where divine magic comes from.

It’s remarkably neat how it all fits together. Whatever 4E did wrong in terms of its setting design (a topic I’ve grumped about before), I can’t fault it for actually taking the time to think about what its default setting implies in terms of the game mechanics, nor for the answers it came up with in this particular respect.

A new existence develops during this process of interchange: a new body is created. Hermes calls it a fiery body. It is more dazzling than a flash of lightning and totally independent of the earthly vehicles of the personality. It is rightly called a spiritual body, a body formed by the spirit directly from the astral primordial substance, a soma psychikon, a golden wedding garment. And Hermes emphasizes that although this preparation takes place with the aid of an earthly body, it would be impossible for an earthly body to bear such great divinity. If ever there were too close contact between this fiery garment and the earthly body, the body would certainly be scorched.

So the time comes when there are two separate beings: the earthly man and the heavenly Man.