How we cite our quotes: (Chapter.Paragraph)
Quote #4
Five Great Charters knit the land / together linked, hand in hand / One in the people who wear the crown / Two in the folk who keep the Dead down / Three and Five became stone and mortar / Four sees all in frozen water. (17.81)
This nursery rhyme, recited to Sabriel by a young child from the village of Nestowe, explains the history and rules that form the basis of the Charter—this is what has ensured the stability of the Old Kingdom for centuries. Repeated in a child's rhyme, its school-like simplicity summarizes a system for controlling some seriously powerful magic.
Quote #5
"The people, or whatever they were who made the great Charters, put three in bloodlines and two in physical constructions: the Wall and the Great Stones. All the lesser stones draw power from one or the other." (18.51)
As Touchstone explains here, the need for order in the Old Kingdom is so great that the powerful magic system runs through walls, stone, and even blood. We don't get to find out how this system was created, and it doesn't sound like Touchstone knows even though he's been around for over two hundred years—which means this is a seriously old system of rules.
Quote #6
"Somewhere along the path of his studies, he'd swapped real Life for power and, like all the Dead, he needed to take life all the time to stay out of Death. But the Charter made it very difficult for him to do that anywhere in the Kingdom. So he decided to break the Charter." (18.67)
The rules that govern the use of magic are clearly in place so that corrupted sorcerers—like Kerrigor—don't take advantage of the supernatural powers in the Old Kingdom. Breaking these rules, in the form of the Charter, is seen as the ultimate in evil.