Possible Clues:

• High ethical standards
• Doubts about the morality of an action
• Feelings of doubt produced by conscience
• Moral reservations
• Doubts prison officer holds back reportedly
• Units of precious material bringing a certain uneasiness
• What con artists lack
• Deterrents to improper conduct, namely regulations about parking
• 'The Game of Moral Dilemmas'
• Moral compass