Related Clues:

• One who questions people's motives
• Adherent to an ancient Greek school of philosophy founded by Antisthenes
• Sceptic, fault-finding critic
• Pessimist showing limits to civility, not entirely pleasant
• One who tends to think the worst of others
• Fallacy nicely traps one disinclined to believe
• Some kleptocracy — nicking? One believes the worst
• Misanthrope showing a little mercy? Nice!