The Seventh Stricture is a book found in Dishonored.
[Excerpt from a work detailing one of the Seven Strictures]
Restrict an errant mind before it becomes fractious and divided. Can two enemies occupy the same body? No, for the first will direct it one way, and the second another, until they stumble into a ditch and its neck is broken. Likewise, two contrary thoughts cannot long abide in a man's mind, or he will become weak-willed and subject to any heresy.