A particular verse from Brain Damage which reads:
You re-arrange me 'till I'm sane.
I believe this verse to be speaking of how sometimes one needs another to take initiative in order to change or help someone for better or for worse.
Blade: This change is so drastic, yet so necessary (in the eyes of the beholder), that it can't help but be done with some pain or sacrifice involved. It also demonstrates how someone else must raise the blade, and take that first step.
Interesting that blade can be made out to mean anything from a surgical knife, to a sword. Thus, the method by which the change is made can vary drastically.
Change: The change must occur, and it must be done with someone else's hand. They make the change, and thus, they become responsible for the result.
Sane: It shouldn't be expected to succeed on the first try. You need to keep on trying until the desired result is achieved. Quiting and running away from the situation while you're half done will result in the focus being less sane than before. However, if you succeed in your desired changes, then the focus will be "sane".
*** But to what extent? Are such changes necessary in the first place? What if the focus agrees? What is the definition of sanity? Is it all relative? Thus either for good or for evil?