Once a person becomes Awakened, she risks losing equilibrium with the real world. Her ability to literally make her dreams come true, to wield raw power over others, is a terrible temptation. Many succumb to the allure of power and Reach beyond their capabilities, enticed by their own Hubris and their obsessions with Mysteries. When Wisdom reaches zero, the mage breaks, becoming one of the Mad, his own soul jagged by his Hubris.
Wisdom measures how much control a mage has over his own magic. Wisdom lies in knowing when to employ magic and when not, in avoiding damaging and manipulating people with probably Paradox-infused magic, especially when they have no defense against the raw supernal powers a mage commands.
The Awakened measure Wisdom in roughly three tiers: Enlightened Wisdom, possessed by mages with a high understanding of their own actions; Understanding, the standard tier for most mages and Falling Wisdom, where a mage begins to become obsessive and more paradox-prone.
Not all Orders view a cultivation of Wisdom as positive. The Silver Ladder derides mages who deny themselves their powers, stating that "Hubris is a coward's word". Likewise, the Seers of the Throne rarely care much enough about Sleepers to grow beyond Understanding.