Possible Clues:

• Madness
• Extreme foolishness
• 'Mind, it's not right, but it's only a tiny sin (8)'
• Perhaps where there's a nit there's a nut
• Lunacy, derangement
• Unmitigated folly
• A river flows out of dirty folly
• Stupidity, holding saint to show madness
• Such batty stupidity about the South!
• Psychopathy