Orders is orders

Quote of the day:

Look to authority for orders, filter them through a fine mesh of common sense with a decent dollop of creative misunderstanding and occasional insidious deafness because authority doesn't understand the reality at street level.

For some reason I'm reminded of this in the midst of the various revelations about UK and US involvement and complicity in torture. I think this is from Terry Prachett's Night Watch but can't be entirely sure.