Possible Clues:

• Principle of the change in command
• In principle that's the confusion, I see
• In principle this could sound high among all the rest
• The confusion, I see, is a moral matter
• Changing the 99 rules of behaviour
• On principle he may have a tic
• That's enough to finish off 10 across
• ... and this Roman acquired moral principles
• Hard work may be part of it
• The confusion, I see, is a moral one