Dissonance

A very essential part of the Lie is the inability of the Sleepers to cope with the higher truths of the Realms Supernal if confronted directly with them. If a sleeper bears witness to an act of vulgar magic, Disbelief forces him to forget the incident as anything unusual. This can diminish the spell potency and even dispell an effect completly. It also increases the chance of triggering Paradox.

Mages debate endlessly about why this is so. Ancient records have no references to any such effect before the fall of Atlantis and the division of the worlds. It seems that human souls, cut off from the Supernal World and exiled to the Fallen World, cannot cope with the truth of magic. Something violently tries to keep their eyes shut. Vampires, werewolves, spirits, ghosts, and other strange beings can use their powers freely before the eyes of Sleepers. Mages theorize that Disbelief is a Sleeper's soul denying the truth of the Supernal World, as displayed by vulgar Awakened magic. The powers of other creatures, mages believe, originate in the Fallen World and do not stir the soul's memory of its fallen tragedy. In a sense, Disbelief is a near Awakening, but one that denies Awakening itself.