Within the Anima Mundi, the concepts a mage is exposed to become so grand, all-encompassing and complex that a mortal soul would be subsumed into them if exposed to long. Mages counter this by creating an Amnion around them. The Amnion is a sheath of individualism woven from the will and nimbus that protects mages from the dangers of the realm. This, however, makes it harder for a mage to comprehend the symbols and entities he witnesses in the Anima Mundi, so some eschew the use of an Amnion to better communicate with the realm.
- Astral Realms, p.72