There is an old myth about the spine: it is the last part of a mortal man to decay. While the worms take the flesh and the trees drink the blood, the spine remains resolute and firm. It is the rod that resists the dissolution into nothingness that comes at the end of a man's life.
In the secret ceremonies that initiate boy into man and man into penitent, the acolytes of the Abandoned Sun demonstrate how the spine of a man—regardless of its rigidity or its resistance to decay—is still nothing more than a stick by which the body may be controlled. "All of your secrets are revealed in the triangles of your spine," they tell the initiate. "Your love can be turned to hate with a simple cut. Your fear can be transformed into bravery with just a little squeeze. By removing one tiny bone, we can redirect your disgust and revulsion into a limitless passion."
No will is impervious. As long as there is doubt.