Related Clues:

• Motive questioner
• Misanthrope
• Negative sort of person
• Diogenes, notably
• Nonbeliever
• Doubting Thomas
• Greek philosopher
• Distrusting sort
• Pessimist
• Pessimistic type
• Sour sort
• Glass-half-empty type
• Distrustful sort
• Doubter
• Suspicious sourpuss