Related Clues:

• Rationality
• Reason
• Good sense
• Marbles, so to speak
• Soundness of mind
• Sensibleness
• Loss of the certifiable
• Good reason
• Reasonableness
• Marbles you don't play with
• Lose yours and you're nuts
• Mental health
• Sound quality?
• Clearmindedness
• Reason and coherence